For regmove if we could not improve code by changing the source to the destination...

[official-gcc.git] / texinfo / texinfo.texi

\input texinfo.tex    @c -*-texinfo-*-
@comment %**start of header
@setfilename texinfo
@settitle Texinfo @value{edition}
@c Define a new index for options.
@defcodeindex op
@c Put everything except function (command, in this case) names in one
index (arbitrarily chosen to be the concept index).
@syncodeindex op cp
@syncodeindex vr cp
@syncodeindex pg cp
@footnotestyle separate
@paragraphindent 2
@finalout
@comment %**end of header
@comment $Id: texinfo.texi,v 1.2 1998/03/24 17:58:30 law Exp $

@c Before release, run C-u C-c C-u C-a (texinfo-all-menus-update with a
@c prefix arg).  This updates the node pointers, which texinfmt.el needs.

@dircategory Texinfo documentation system
@direntry
* Texinfo: (texinfo).           The GNU documentation format.
* install-info: (texinfo)Invoking install-info. Updating info/dir entries.
* texi2dvi: (texinfo)Format with texi2dvi.      Printing Texinfo documentation.
* texindex: (texinfo)Format with tex/texindex.  Sorting Texinfo index files.
@end direntry

@c Set smallbook if printing in smallbook format so the example of the
@c smallbook font is actually written using smallbook; in bigbook, a kludge
@c is used for TeX output.
@smallbook
@set smallbook
@c @@clear smallbook

@set edition 2.23
@set update-month October 1996
@set update-date 1 @value{update-month}

@c Currently undocumented command, 5 December 1993:
@c
@c nwnode          (Same as node, but no warnings; for `makeinfo'.)

@ifinfo
This file documents Texinfo, a documentation system that can produce
both on-line information and a printed manual from a single source file.

Copyright (C) 1988, 90, 91, 92, 93, 95, 1996 Free Software Foundation, Inc.

This is the second edition of the Texinfo documentation,@*
and is consistent with version 2 of @file{texinfo.tex}.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph
(this paragraph not being relevant to the printed manual).

@end ignore
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Free Software Foundation.
@end ifinfo

@setchapternewpage odd

@shorttitlepage Texinfo

@titlepage
@c use the new format for titles
@title Texinfo
@subtitle The GNU Documentation Format
@subtitle Edition @value{edition}, for Texinfo Version Three
@subtitle @value{update-month}

@author Robert J.@: Chassell
@author Richard M.@: Stallman

@c Include the Distribution inside the titlepage so
@c that headings are turned off.

@page
@vskip 0pt plus 1filll
Copyright @copyright{} 1988, 1990, 1991, 1992, 1993, 1995, 1996 Free Software Foundation, Inc.

@sp 2
This is the second edition of the Texinfo documentation,@*
and is consistent with version 2 of @file{texinfo.tex}.
@sp 2

Published by the Free Software Foundation @*
59 Temple Place Suite 330, @*
Boston, MA 02111-1307 USA @*
Printed copies are available for $15 each.@*
ISBN 1-882114-64-7
@c ISBN 1-882114-63-9 is for edition 2.20 of 28 February 1995
@c ISBN 1-882114-64-7 is for edition 2.23 of 1 October 1996.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Free Software Foundation.
@sp 2
Cover art by Etienne Suvasa.
@end titlepage

@ifinfo
@node Top, Copying, (dir), (dir)
@top Texinfo

Texinfo is a documentation system that uses a single source file to
produce both on-line information and printed output.@refill

The first part of this master menu lists the major nodes in this Info
document, including the @@-command and concept indices.  The rest of
the menu lists all the lower level nodes in the document.@refill

This is Edition @value{edition} of the Texinfo documentation,
@w{@value{update-date},} for Texinfo Version Three.
@end ifinfo

@c Here is a spare copy of the chapter menu entry descriptions,
@c in case they are accidently deleted
@ignore
Your rights.
Texinfo in brief.
How to use Texinfo mode.
What is at the beginning of a Texinfo file?
What is at the end of a Texinfo file?
How to create chapters, sections, subsections,
  appendices, and other parts.
How to provide structure for a document.
How to write nodes.
How to write menus.
How to write cross references.
How to mark words and phrases as code,
  keyboard input, meta-syntactic
  variables, and the like.
How to write quotations, examples, etc.
How to write lists and tables.
How to create indices.
How to insert @@-signs, braces, etc.
How to indicate results of evaluation,
  expansion of macros, errors, etc.
How to force and prevent line and page breaks.
How to describe functions and the like in a uniform manner.
How to write footnotes.
How to specify text for either @TeX{} or Info.
How to print hardcopy.
How to create an Info file.
How to install an Info file
A list of all the Texinfo @@-commands.
Hints on how to write a Texinfo document.
A sample Texinfo file to look at.
Tell readers they have the right to copy
  and distribute.
How to incorporate other Texinfo files.
How to write page headings and footings.
How to find formatting mistakes.
All about paragraph refilling.
A description of @@-Command syntax.
Texinfo second edition features.
A menu containing commands and variables.
A menu covering many topics.
@end ignore

@menu
* Copying::                     Your rights.
* Overview::                    Texinfo in brief.
* Texinfo Mode::                How to use Texinfo mode.
* Beginning a File::            What is at the beginning of a Texinfo file?
* Ending a File::               What is at the end of a Texinfo file?
* Structuring::                 How to create chapters, sections, subsections,
                                  appendices, and other parts.
* Nodes::                       How to write nodes.
* Menus::                       How to write menus.
* Cross References::            How to write cross references.
* Marking Text::                How to mark words and phrases as code,
                                  keyboard input, meta-syntactic
                                  variables, and the like.
* Quotations and Examples::     How to write quotations, examples, etc.
* Lists and Tables::            How to write lists and tables.
* Indices::                     How to create indices.
* Insertions::                  How to insert @@-signs, braces, etc.
* Glyphs::                      How to indicate results of evaluation,
                                  expansion of macros, errors, etc.
* Breaks::                      How to force and prevent line and page breaks.
* Definition Commands::         How to describe functions and the like
                                  in a uniform manner.
* Footnotes::                   How to write footnotes.
* Conditionals::                How to specify text for either @TeX{} or Info.
* Macros::                      Defining new Texinfo commands.
* Format/Print Hardcopy::       How to convert a Texinfo file to a file
                                  for printing and how to print that file.
* Create an Info File::         Convert a Texinfo file into an Info file.
* Install an Info File::        Make an Info file accessible to users.
* Command List::                All the Texinfo @@-commands.
* Tips::                        Hints on how to write a Texinfo document.
* Sample Texinfo File::         A sample Texinfo file to look at.
* Sample Permissions::          Tell readers they have the right to copy
                                  and distribute.
* Include Files::               How to incorporate other Texinfo files.
* Headings::                    How to write page headings and footings.
* Catching Mistakes::           How to find formatting mistakes.
* Refilling Paragraphs::        All about paragraph refilling.
* Command Syntax::              A description of @@-Command syntax.
* Obtaining TeX::               How to Obtain @TeX{}.
* New Features::                Texinfo second edition features.
* Command and Variable Index::  A menu containing commands and variables.
* Concept Index::               A menu covering many topics.

@detailmenu

 --- The Detailed Node Listing ---

Overview of Texinfo

* Using Texinfo::               Create a conventional printed book
                                  or an Info file.
* Info Files::                  What is an Info file?
* Printed Books::               Characteristics of a printed book or manual.
* Formatting Commands::         @@-commands are used for formatting.
* Conventions::                 General rules for writing a Texinfo file.
* Comments::                    How to write comments and mark regions that
                                  the formatting commands will ignore.
* Minimum::                     What a Texinfo file must have.
* Six Parts::                   Usually, a Texinfo file has six parts.
* Short Sample::                A short sample Texinfo file.
* Acknowledgements::            

Using Texinfo Mode

* Texinfo Mode Overview::       How Texinfo mode can help you.
* Emacs Editing::               Texinfo mode adds to GNU Emacs' general
                                  purpose editing features.
* Inserting::                   How to insert frequently used @@-commands.
* Showing the Structure::       How to show the structure of a file.
* Updating Nodes and Menus::    How to update or create new nodes and menus.
* Info Formatting::             How to format for Info.
* Printing::                    How to format and print part or all of a file.
* Texinfo Mode Summary::        Summary of all the Texinfo mode commands.

Updating Nodes and Menus

* Updating Commands::           Five major updating commands.
* Updating Requirements::       How to structure a Texinfo file for
                                  using the updating command.
* Other Updating Commands::     How to indent descriptions, insert
                                  missing nodes lines, and update
                                  nodes in sequence.

Beginning a Texinfo File

* Four Parts::                  Four parts begin a Texinfo file.
* Sample Beginning::            Here is a sample beginning for a Texinfo file.
* Header::                      The very beginning of a Texinfo file.
* Info Summary and Permissions::  Summary and copying permissions for Info.
* Titlepage & Copyright Page::  Creating the title and copyright pages.
* The Top Node::                Creating the `Top' node and master menu.
* Software Copying Permissions::  Ensure that you and others continue to
                                  have the right to use and share software.

The Texinfo File Header

* First Line::                  The first line of a Texinfo file.
* Start of Header::             Formatting a region requires this.
* setfilename::                 Tell Info the name of the Info file.
* settitle::                    Create a title for the printed work.
* setchapternewpage::           Start chapters on right-hand pages.
* paragraphindent::             An option to specify paragraph indentation.
* End of Header::               Formatting a region requires this.

The Title and Copyright Pages

* titlepage::                   Create a title for the printed document.
* titlefont center sp::         The @code{@@titlefont}, @code{@@center},
                                  and @code{@@sp} commands.
* title subtitle author::       The @code{@@title}, @code{@@subtitle},
                                  and @code{@@author} commands.
* Copyright & Permissions::     How to write the copyright notice and
                                  include copying permissions.
* end titlepage::               Turn on page headings after the title and
                                  copyright pages.
* headings on off::             An option for turning headings on and off
                                  and double or single sided printing.

The `Top' Node and Master Menu

* Title of Top Node::           Sketch what the file is about.
* Master Menu Parts::           A master menu has three or more parts.

Ending a Texinfo File

* Printing Indices & Menus::    How to print an index in hardcopy and
                                  generate index menus in Info.
* Contents::                    How to create a table of contents.
* File End::                    How to mark the end of a file.

Chapter Structuring

* Tree Structuring::            A manual is like an upside down tree @dots{}
* Structuring Command Types::   How to divide a manual into parts.
* makeinfo top::                The @code{@@top} command, part of the `Top' node.
* chapter::                     
* unnumbered & appendix::       
* majorheading & chapheading::  
* section::                     
* unnumberedsec appendixsec heading::  
* subsection::                  
* unnumberedsubsec appendixsubsec subheading::  
* subsubsection::               Commands for the lowest level sections.
* Raise/lower sections::        How to change commands' hierarchical level.

Nodes

* Two Paths::                   Different commands to structure
                                  Info output and printed output.
* Node Menu Illustration::      A diagram, and sample nodes and menus.
* node::                        How to write a node, in detail.
* makeinfo Pointer Creation::   How to create node pointers with @code{makeinfo}.

The @code{@@node} Command

* Node Names::                  How to choose node and pointer names.
* Writing a Node::              How to write an @code{@@node} line.
* Node Line Tips::              Keep names short.
* Node Line Requirements::      Keep names unique, without @@-commands.
* First Node::                  How to write a `Top' node.
* makeinfo top command::        How to use the @code{@@top} command.
* Top Node Summary::            Write a brief description for readers.

Menus

* Menu Location::               Put a menu in a short node.
* Writing a Menu::              What is a menu?
* Menu Parts::                  A menu entry has three parts.
* Less Cluttered Menu Entry::   Two part menu entry.
* Menu Example::                Two and three part menu entries.
* Other Info Files::            How to refer to a different Info file.

Cross References

* References::                  What cross references are for.
* Cross Reference Commands::    A summary of the different commands.
* Cross Reference Parts::       A cross reference has several parts.
* xref::                        Begin a reference with `See' @dots{}
* Top Node Naming::             How to refer to the beginning of another file.
* ref::                         A reference for the last part of a sentence.
* pxref::                       How to write a parenthetical cross reference.
* inforef::                     How to refer to an Info-only file.

@code{@@xref}

* Reference Syntax::            What a reference looks like and requires.
* One Argument::                @code{@@xref} with one argument.
* Two Arguments::               @code{@@xref} with two arguments.
* Three Arguments::             @code{@@xref} with three arguments.
* Four and Five Arguments::     @code{@@xref} with four and five arguments.

Marking Words and Phrases

* Indicating::                  How to indicate definitions, files, etc.
* Emphasis::                    How to emphasize text.

Indicating Definitions, Commands, etc.

* Useful Highlighting::         Highlighting provides useful information.
* code::                        How to indicate code.
* kbd::                         How to show keyboard input.
* key::                         How to specify keys.
* samp::                        How to show a literal sequence of characters.
* var::                         How to indicate a metasyntactic variable.
* file::                        How to indicate the name of a file.
* dfn::                         How to specify a definition.
* cite::                        How to refer to a book that is not in Info.
* url::                         How to indicate a world wide web reference.
* email::                       How to indicate an electronic mail address.

Emphasizing Text

* emph & strong::               How to emphasize text in Texinfo.
* Smallcaps::                   How to use the small caps font.
* Fonts::                       Various font commands for printed output.
* Customized Highlighting::     How to define highlighting commands.

Quotations and Examples

* Block Enclosing Commands::    Use different constructs for
                                  different purposes.
* quotation::                   How to write a quotation.
* example::                     How to write an example in a fixed-width font.
* noindent::                    How to prevent paragraph indentation.
* Lisp Example::                How to illustrate Lisp code.
* smallexample & smalllisp::    Forms for the @code{@@smallbook} option.
* display::                     How to write an example in the current font.
* format::                      How to write an example that does not narrow
                                  the margins.
* exdent::                      How to undo the indentation of a line.
* flushleft & flushright::      How to push text flushleft or flushright.
* cartouche::                   How to draw cartouches around examples.

Making Lists and Tables

* Introducing Lists::           Texinfo formats lists for you.
* itemize::                     How to construct a simple list.
* enumerate::                   How to construct a numbered list.
* Two-column Tables::           How to construct a two-column table.
* Multi-column Tables::         How to construct generalized tables.

Making a Two-column Table

* table::                       How to construct a two-column table.
* ftable vtable::               How to construct a two-column table
                                  with automatic indexing.
* itemx::                       How to put more entries in the first column.

Multi-column Tables

* Multitable Column Widths::    Defining multitable column widths.
* Multitable Rows::             Defining multitable rows, with examples.

Creating Indices

* Index Entries::               Choose different words for index entries.
* Predefined Indices::          Use different indices for different kinds
                                  of entry.
* Indexing Commands::           How to make an index entry.
* Combining Indices::           How to combine indices.
* New Indices::                 How to define your own indices.

Combining Indices

* syncodeindex::                How to merge two indices, using @code{@@code}
                                  font for the merged-from index.
* synindex::                    How to merge two indices, using the
                                  default font of the merged-to index.

Special Insertions

* Braces Atsigns::              How to insert braces, @samp{@@}.
* Inserting Space::             How to insert the right amount of space
                                  within a sentence.
* Inserting Accents::           How to insert accents and special characters.
* Dots Bullets::                How to insert dots and bullets.
* TeX and copyright::           How to insert the @TeX{} logo
                                  and the copyright symbol.
* pounds::                      How to insert the pounds currency symbol.
* minus::                       How to insert a minus sign.
* math::                        How to format a mathematical expression.

Inserting @@ and Braces

* Inserting An Atsign::         How to insert @samp{@@}.
* Inserting Braces::            How to insert @samp{@{} and @samp{@}}.

Inserting Space

* Not Ending a Sentence::       Sometimes a . doesn't end a sentence.
* Ending a Sentence::           Sometimes it does.
* Multiple Spaces::             Inserting multiple spaces.
* dmn::                         How to format a dimension.

Inserting Ellipsis, Dots, and Bullets

* dots::                        How to insert dots @dots{}
* bullet::                      How to insert a bullet.

Inserting @TeX{} and the Copyright Symbol

* tex::                         How to insert the @TeX{} logo.
* copyright symbol::            How to use @code{@@copyright}@{@}.

Glyphs for Examples

* Glyphs Summary::              
* result::                      How to show the result of expression.
* expansion::                   How to indicate an expansion.
* Print Glyph::                 How to indicate printed output.
* Error Glyph::                 How to indicate an error message.
* Equivalence::                 How to indicate equivalence.
* Point Glyph::                 How to indicate the location of point.

Making and Preventing Breaks

* Break Commands::              Cause and prevent splits.
* Line Breaks::                 How to force a single line to use two lines.
* - and hyphenation::           How to tell TeX about hyphenation points.
* w::                           How to prevent unwanted line breaks.
* sp::                          How to insert blank lines.
* page::                        How to force the start of a new page.
* group::                       How to prevent unwanted page breaks.
* need::                        Another way to prevent unwanted page breaks.

Definition Commands

* Def Cmd Template::            How to structure a description using a
                                  definition command.
* Optional Arguments::          How to handle optional and repeated arguments.
* deffnx::                      How to group two or more `first' lines.
* Def Cmds in Detail::          All the definition commands.
* Def Cmd Conventions::         Conventions for writing definitions.
* Sample Function Definition::  

The Definition Commands

* Functions Commands::          Commands for functions and similar entities.
* Variables Commands::          Commands for variables and similar entities.
* Typed Functions::             Commands for functions in typed languages.
* Typed Variables::             Commands for variables in typed languages.
* Abstract Objects::            Commands for object-oriented programming.
* Data Types::                  The definition command for data types.

Footnotes

* Footnote Commands::           How to write a footnote in Texinfo.
* Footnote Styles::             Controlling how footnotes appear in Info.

Conditionally Visible Text

* Conditional Commands::        How to specify text for HTML, Info, or @TeX{}.
* Using Ordinary TeX Commands::  You can use any and all @TeX{} commands.
* set clear value::             How to designate which text to format (for
                                  both Info and @TeX{}); and how to set a
                                  flag to a string that you can insert.

@code{@@set}, @code{@@clear}, and @code{@@value}

* ifset ifclear::               Format a region if a flag is set.
* value::                       Replace a flag with a string.
* value Example::               An easy way to update edition information.

Macros: Defining New Texinfo Commands

* Defining Macros::             Both defining and undefining new commands.
* Invoking Macros::             Using a macro, once you've defined it.

Format and Print Hardcopy

* Use TeX::                     Use @TeX{} to format for hardcopy.
* Format with tex/texindex::    How to format in a shell.
* Format with texi2dvi::        A simpler way to use the shell.
* Print with lpr::              How to print.
* Within Emacs::                How to format and print from an Emacs shell.
* Texinfo Mode Printing::       How to format and print in Texinfo mode.
* Compile-Command::             How to print using Emacs's compile command.
* Requirements Summary::        @TeX{} formatting requirements summary.
* Preparing for TeX::           What you need to do to use @TeX{}.
* Overfull hboxes::             What are and what to do with overfull hboxes.
* smallbook::                   How to print small format books and manuals.
* A4 Paper::                    How to print on European A4 paper.
* Cropmarks and Magnification::  How to print marks to indicate the size
                                of pages and how to print scaled up output.

Creating an Info File

* makeinfo advantages::         @code{makeinfo} provides better error checking.
* Invoking makeinfo::           How to run @code{makeinfo} from a shell.
* makeinfo options::            Specify fill-column and other options.
* Pointer Validation::          How to check that pointers point somewhere.
* makeinfo in Emacs::           How to run @code{makeinfo} from Emacs.
* texinfo-format commands::     Two Info formatting commands written
                                  in Emacs Lisp are an alternative
                                  to @code{makeinfo}.
* Batch Formatting::            How to format for Info in Emacs Batch mode.
* Tag and Split Files::         How tagged and split files help Info
                                  to run better.

Installing an Info File

* Directory file::              The top level menu for all Info files.
* New Info File::               Listing a new info file.
* Other Info Directories::      How to specify Info files that are
                                  located in other directories.
* Installing Dir Entries::      How to specify what menu entry to add
                                  to the Info directory.
* Invoking install-info::       @code{install-info} options.

Sample Permissions

* Inserting Permissions::       How to put permissions in your document.
* ifinfo Permissions::          Sample @samp{ifinfo} copying permissions.
* Titlepage Permissions::       Sample Titlepage copying permissions.

Include Files

* Using Include Files::         How to use the @code{@@include} command.
* texinfo-multiple-files-update::  How to create and update nodes and
                                  menus when using included files.
* Include File Requirements::   What @code{texinfo-multiple-files-update} expects.
* Sample Include File::         A sample outer file with included files
                                  within it; and a sample included file.
* Include Files Evolution::     How use of the @code{@@include} command
                                  has changed over time.

Page Headings

* Headings Introduced::         Conventions for using page headings.
* Heading Format::              Standard page heading formats.
* Heading Choice::              How to specify the type of page heading.
* Custom Headings::             How to create your own headings and footings.

Formatting Mistakes

* makeinfo preferred::          @code{makeinfo} finds errors.
* Debugging with Info::         How to catch errors with Info formatting.
* Debugging with TeX::          How to catch errors with @TeX{} formatting.
* Using texinfo-show-structure::  How to use @code{texinfo-show-structure}.
* Using occur::                 How to list all lines containing a pattern.
* Running Info-Validate::       How to find badly referenced nodes.

Finding Badly Referenced Nodes

* Using Info-validate::         How to run @code{Info-validate}.
* Unsplit::                     How to create an unsplit file.
* Tagifying::                   How to tagify a file.
* Splitting::                   How to split a file manually.

Second Edition Features

* New Texinfo Mode Commands::   The updating commands are especially useful.
* New Commands::                Many newly described @@-commands.
@end detailmenu
@end menu

@node Copying, Overview, Top, Top
@comment  node-name, next, previous,  up
@unnumbered Texinfo Copying Conditions
@cindex Copying conditions
@cindex Conditions for copying Texinfo

The programs currently being distributed that relate to Texinfo include
portions of GNU Emacs, plus other separate programs (including
@code{makeinfo}, @code{info}, @code{texindex}, and @file{texinfo.tex}).
These programs are @dfn{free}; this means that everyone is free to use
them and free to redistribute them on a free basis.  The Texinfo-related
programs are not in the public domain; they are copyrighted and there
are restrictions on their distribution, but these restrictions are
designed to permit everything that a good cooperating citizen would want
to do.  What is not allowed is to try to prevent others from further
sharing any version of these programs that they might get from
you.@refill

  Specifically, we want to make sure that you have the right to give
away copies of the programs that relate to Texinfo, that you receive
source code or else can get it if you want it, that you can change these
programs or use pieces of them in new free programs, and that you know
you can do these things.@refill

  To make sure that everyone has such rights, we have to forbid you to
deprive anyone else of these rights.  For example, if you distribute
copies of the Texinfo related programs, you must give the recipients all
the rights that you have.  You must make sure that they, too, receive or
can get the source code.  And you must tell them their rights.@refill

  Also, for our own protection, we must make certain that everyone finds
out that there is no warranty for the programs that relate to Texinfo.
If these programs are modified by someone else and passed on, we want
their recipients to know that what they have is not what we distributed,
so that any problems introduced by others will not reflect on our
reputation.@refill

  The precise conditions of the licenses for the programs currently
being distributed that relate to Texinfo are found in the General Public
Licenses that accompany them.@refill

@node Overview, Texinfo Mode, Copying, Top
@comment  node-name,  next,  previous,  up
@chapter Overview of Texinfo
@cindex Overview of Texinfo
@cindex Texinfo overview

@dfn{Texinfo}@footnote{Note that the first syllable of ``Texinfo'' is
pronounced like ``speck'', not ``hex''.  This odd pronunciation is
derived from, but is not the same as, the pronunciation of @TeX{}.  In
the word @TeX{}, the @samp{X} is actually the Greek letter ``chi''
rather than the English letter ``ex''.  Pronounce @TeX{} as if the
@samp{X} were the last sound in the name `Bach'; but pronounce Texinfo
as if the @samp{x} were a `k'.  Spell ``Texinfo'' with a capital ``T''
and write the other letters in lower case.}
is a documentation system that uses a single source file to produce both
on-line information and printed output.  This means that instead of
writing two different documents, one for the on-line help or other on-line
information and the other for a typeset manual or other printed work, you
need write only one document.  When the work is revised, you need revise
only one document.  (You can read the on-line information, known as an
@dfn{Info file}, with an Info documentation-reading program.)@refill

@menu
* Using Texinfo::               Create a conventional printed book
                                  or an Info file.
* Info Files::                  What is an Info file?
* Printed Books::               Characteristics of a printed book or manual.
* Formatting Commands::         @@-commands are used for formatting.
* Conventions::                 General rules for writing a Texinfo file.
* Comments::                    How to write comments and mark regions that
                                  the formatting commands will ignore.
* Minimum::                     What a Texinfo file must have.
* Six Parts::                   Usually, a Texinfo file has six parts.
* Short Sample::                A short sample Texinfo file.
* Acknowledgements::            
@end menu

@node Using Texinfo, Info Files, Overview, Overview
@ifinfo
@heading Using Texinfo
@end ifinfo

Using Texinfo, you can create a printed document with the normal
features of a book, including chapters, sections, cross references,
and indices.  From the same Texinfo source file, you can create a
menu-driven, on-line Info file with nodes, menus, cross references,
and indices.  You can, if you wish, make the chapters and sections of
the printed document correspond to the nodes of the on-line
information; and you use the same cross references and indices for
both the Info file and the printed work.  @cite{The GNU
Emacs Manual} is a good example of a Texinfo file, as is this manual.@refill

To make a printed document, you process a Texinfo source file with the
@TeX{} typesetting program.  This creates a @sc{dvi} file that you can
typeset and print as a book or report.  (Note that the Texinfo language
is completely different from @TeX{}'s usual language, plain @TeX{}.)  If
you do not have @TeX{}, but do have @code{troff} or @code{nroff}, you
can use the @code{texi2roff} program instead.@refill

To make an Info file, you process a Texinfo source file with the
@code{makeinfo} utility or Emacs's @code{texinfo-format-buffer} command;
this creates an Info file that you can install on-line.@refill

@TeX{} and @code{texi2roff} work with many types of printer; similarly,
Info works with almost every type of computer terminal.  This power
makes Texinfo a general purpose system, but brings with it a constraint,
which is that a Texinfo file may contain only the customary
``typewriter'' characters (letters, numbers, spaces, and punctuation
marks) but no special graphics.@refill

A Texinfo file is a plain @sc{ascii} file containing text and
@dfn{@@-commands} (words preceded by an @samp{@@}) that tell the
typesetting and formatting programs what to do.  You may edit a
Texinfo file with any text editor; but it is especially convenient to
use GNU Emacs since that editor has a special mode, called Texinfo
mode, that provides various Texinfo-related features.  (@xref{Texinfo
Mode}.)@refill

Before writing a Texinfo source file, you should become familiar with
the Info documentation reading program and learn about nodes,
menus, cross references, and the rest.  (@inforef{Top, info, info},
for more information.)@refill

You can use Texinfo to create both on-line help and printed manuals;
moreover, Texinfo is freely redistributable.  For these reasons, Texinfo
is the format in which documentation for GNU utilities and libraries is
written.@refill

@node Info Files, Printed Books, Using Texinfo, Overview
@comment  node-name,  next,  previous,  up
@section Info files
@cindex Info files

An Info file is a Texinfo file formatted so that the Info documentation
reading program can operate on it.  (@code{makeinfo}
and @code{texinfo-format-buffer} are two commands that convert a Texinfo file
into an Info file.)@refill

Info files are divided into pieces called @dfn{nodes}, each of which
contains the discussion of one topic.  Each node has a name, and
contains both text for the user to read and pointers to other nodes,
which are identified by their names.  The Info program displays one node
at a time, and provides commands with which the user can move to other
related nodes.@refill

@ifinfo
@inforef{Top, info, info}, for more information about using Info.@refill
@end ifinfo

Each node of an Info file may have any number of child nodes that
describe subtopics of the node's topic.  The names of child
nodes are listed in a @dfn{menu} within the parent node; this
allows you to use certain Info commands to move to one of the child
nodes.  Generally, an Info file is organized like a book.  If a node
is at the logical level of a chapter, its child nodes are at the level
of sections; likewise, the child nodes of sections are at the level
of subsections.@refill

All the children of any one parent are linked together in a
bidirectional chain of `Next' and `Previous' pointers.  The `Next'
pointer provides a link to the next section, and the `Previous' pointer
provides a link to the previous section.  This means that all the nodes
that are at the level of sections within a chapter are linked together.
Normally the order in this chain is the same as the order of the
children in the parent's menu.  Each child node records the parent node
name as its `Up' pointer.  The last child has no `Next' pointer, and the
first child has the parent both as its `Previous' and as its `Up'
pointer.@footnote{In some documents, the first child has no `Previous'
pointer.  Occasionally, the last child has the node name of the next
following higher level node as its `Next' pointer.}@refill

The book-like structuring of an Info file into nodes that correspond
to chapters, sections, and the like is a matter of convention, not a
requirement.  The `Up', `Previous', and `Next' pointers of a node can
point to any other nodes, and a menu can contain any other nodes.
Thus, the node structure can be any directed graph.  But it is usually
more comprehensible to follow a structure that corresponds to the
structure of chapters and sections in a printed book or report.@refill

In addition to menus and to `Next', `Previous', and `Up' pointers, Info
provides pointers of another kind, called references, that can be
sprinkled throughout the text.  This is usually the best way to
represent links that do not fit a hierarchical structure.@refill

Usually, you will design a document so that its nodes match the
structure of chapters and sections in the printed output.  But there
are times when this is not right for the material being discussed.
Therefore, Texinfo uses separate commands to specify the node
structure for the Info file and the section structure for the printed
output.@refill

Generally, you enter an Info file through a node that by convention is
called @samp{Top}.  This node normally contains just a brief summary
of the file's purpose, and a large menu through which the rest of the
file is reached.  From this node, you can either traverse the file
systematically by going from node to node, or you can go to a specific
node listed in the main menu, or you can search the index menus and
then go directly to the node that has the information you want.@refill
@c !!! With the standalone Info system you may go to specific nodes
@c directly..

If you want to read through an Info file in sequence, as if it were a
printed manual, you can get the whole file with the advanced Info
command @kbd{g* @key{RET}}.  (@inforef{Expert, Advanced Info commands,
info}.)@refill

@c !!! dir file may be located in one of many places:
@c     /usr/local/emacs/info            mentioned in info.c DEFAULT_INFOPATH
@c     /usr/local/lib/emacs/info        mentioned in info.c DEFAULT_INFOPATH
@c     /usr/gnu/info                    mentioned in info.c DEFAULT_INFOPATH
@c     /usr/local/info
@c     /usr/local/lib/info
The @file{dir} file in the @file{info} directory serves as the
departure point for the whole Info system.  From it, you can reach the
`Top' nodes of each of the documents in a complete Info system.@refill

@node Printed Books, Formatting Commands, Info Files, Overview
@comment  node-name,  next,  previous,  up
@section Printed Books
@cindex Printed book and manual characteristics
@cindex Manual characteristics, printed
@cindex Book characteristics, printed
@cindex Texinfo printed book characteristics
@cindex Characteristics, printed books or manuals

@cindex Knuth, Donald
A Texinfo file can be formatted and typeset as a printed book or manual.
To do this, you need @TeX{}, a powerful, sophisticated typesetting
program written by Donald Knuth.@footnote{You can also use the
@code{texi2roff} program if you do not have @TeX{}; since Texinfo is
designed for use with @TeX{}, @code{texi2roff} is not described here.
@code{texi2roff} is part of the standard GNU distribution.}@refill

A Texinfo-based book is similar to any other typeset, printed work: it
can have a title page, copyright page, table of contents, and preface,
as well as chapters, numbered or unnumbered sections and subsections,
page headers, cross references, footnotes, and indices.@refill

You can use Texinfo to write a book without ever having the intention
of converting it into on-line information.  You can use Texinfo for
writing a printed novel, and even to write a printed memo, although
this latter application is not recommended since electronic mail is so
much easier.@refill

@TeX{} is a general purpose typesetting program.  Texinfo provides a
file called @file{texinfo.tex} that contains information (definitions or
@dfn{macros}) that @TeX{} uses when it typesets a Texinfo file.
(@file{texinfo.tex} tells @TeX{} how to convert the Texinfo @@-commands
to @TeX{} commands, which @TeX{} can then process to create the typeset
document.)  @file{texinfo.tex} contains the specifications for printing
a document.@refill

Most often, documents are printed on 8.5 inch by 11 inch
pages (216@dmn{mm} by 280@dmn{mm}; this is the default size), but you
can also print for 7 inch by 9.25 inch pages (178@dmn{mm} by
235@dmn{mm}; the @code{@@smallbook} size) or on European A4 size paper
(@code{@@afourpaper}).  (@xref{smallbook, , Printing ``Small'' Books}.
Also, see @ref{A4 Paper, ,Printing on A4 Paper}.)@refill

By changing the parameters in @file{texinfo.tex}, you can change the
size of the printed document.  In addition, you can change the style in
which the printed document is formatted; for example, you can change the
sizes and fonts used, the amount of indentation for each paragraph, the
degree to which words are hyphenated, and the like.  By changing the
specifications, you can make a book look dignified, old and serious, or
light-hearted, young and cheery.@refill

@TeX{} is freely distributable.  It is written in a dialect of Pascal
called WEB and can be compiled either in Pascal or (by using a
conversion program that comes with the @TeX{} distribution) in C.
(@xref{TeX Mode, ,@TeX{} Mode, emacs, The GNU Emacs Manual}, for information
about @TeX{}.)@refill

@TeX{} is very powerful and has a great many features.  Because a
Texinfo file must be able to present information both on a
character-only terminal in Info form and in a typeset book, the
formatting commands that Texinfo supports are necessarily
limited.@refill

@xref{Obtaining TeX, , How to Obtain @TeX{}}.


@node Formatting Commands, Conventions, Printed Books, Overview
@comment  node-name,  next,  previous,  up
@section @@-commands
@cindex @@-commands
@cindex Formatting commands

In a Texinfo file, the commands that tell @TeX{} how to typeset the
printed manual and tell @code{makeinfo} and
@code{texinfo-format-buffer} how to create an Info file are preceded
by @samp{@@}; they are called @dfn{@@-commands}.  For example,
@code{@@node} is the command to indicate a node and @code{@@chapter}
is the command to indicate the start of a chapter.@refill

@quotation
@strong{Please note:} All the @@-commands, with the exception of the
@code{@@TeX@{@}} command, must be written entirely in lower
case.@refill
@end quotation

The Texinfo @@-commands are a strictly limited set of constructs.  The
strict limits make it possible for Texinfo files to be understood both
by @TeX{} and by the code that converts them into Info files.  You can
display Info files on any terminal that displays alphabetic and
numeric characters.  Similarly, you can print the output generated by
@TeX{} on a wide variety of printers.@refill

Depending on what they do or what arguments@footnote{The word
@dfn{argument} comes from the way it is used in mathematics and does
not refer to a disputation between two people; it refers to the
information presented to the command.  According to the @cite{Oxford
English Dictionary}, the word derives from the Latin for @dfn{to make
clear, prove}; thus it came to mean `the evidence offered as proof',
which is to say, `the information offered', which led to its
mathematical meaning.  In its other thread of derivation, the word
came to mean `to assert in a manner against which others may make
counter assertions', which led to the meaning of `argument' as a
disputation.} they take, you need to write @@-commands on lines of
their own or as part of sentences:@refill

@itemize @bullet
@item
Write a command such as @code{@@noindent} at the beginning of a line as
the only text on the line.  (@code{@@noindent} prevents the beginning of
the next line from being indented as the beginning of a
paragraph.)@refill

@item
Write a command such as @code{@@chapter} at the beginning of a line
followed by the command's arguments, in this case the chapter title, on
the rest of the line.  (@code{@@chapter} creates chapter titles.)@refill

@item
Write a command such as @code{@@dots@{@}} wherever you wish but usually
within a sentence. (@code{@@dots@{@}} creates dots @dots{})@refill

@item
Write a command such as @code{@@code@{@var{sample-code}@}} wherever you
wish (but usually within a sentence) with its argument,
@var{sample-code} in this example, between the braces.  (@code{@@code}
marks text as being code.)@refill

@item
Write a command such as @code{@@example} at the beginning of a line of
its own; write the body-text on following lines; and write the matching
@code{@@end} command, @code{@@end example} in this case, at the
beginning of a line of its own after the body-text. (@code{@@example}
@dots{} @code{@@end example} indents and typesets body-text as an
example.)@refill
@end itemize

@noindent
@cindex Braces, when to use
As a general rule, a command requires braces if it mingles among other
text; but it does not need braces if it starts a line of its own.  The
non-alphabetic commands, such as @code{@@:}, are exceptions to the rule;
they do not need braces.@refill

As you gain experience with Texinfo, you will rapidly learn how to
write the different commands: the different ways to write commands
make it easier to write and read Texinfo files than if all commands
followed exactly the same syntax.  (For details about @@-command
syntax, see @ref{Command Syntax, , @@-Command Syntax}.)@refill

@node Conventions, Comments, Formatting Commands, Overview
@comment  node-name,  next,  previous,  up
@section General Syntactic Conventions
@cindex General syntactic conventions
@cindex Syntactic conventions
@cindex Conventions, syntactic

All printable @sc{ascii} characters except @samp{@@}, @samp{@{} and
@samp{@}} can appear in a Texinfo file and stand for themselves.
@samp{@@} is the escape character which introduces commands.
@samp{@{} and @samp{@}} should be used only to surround arguments to
certain commands.  To put one of these special characters into the
document, put an @samp{@@} character in front of it, like this:
@samp{@@@@}, @samp{@@@{}, and @samp{@@@}}.@refill

@ifinfo
It is customary in @TeX{} to use doubled single-quote characters to
begin and end quotations: ` ` and ' ' (but without a space between the
two single-quote characters).  This convention should be followed in
Texinfo files.  @TeX{} converts doubled single-quote characters to
left- and right-hand doubled quotation marks and Info converts doubled
single-quote characters to @sc{ascii} double-quotes: ` ` and ' ' to " .@refill
@end ifinfo
@iftex
It is customary in @TeX{} to use doubled single-quote characters to
begin and end quotations: @w{@tt{ `` }} and @w{@tt{ '' }}.  This
convention should be followed in Texinfo files.  @TeX{} converts
doubled single-quote characters to left- and right-hand doubled
quotation marks, ``like this'', and Info converts doubled single-quote
characters to @sc{ascii} double-quotes: @w{@tt{ `` }} and
@w{@tt{ '' }} to @w{@tt{ " }}.@refill
@end iftex

Use three hyphens in a row, @samp{---}, for a dash---like this.  In
@TeX{}, a single or even a double hyphen produces a printed dash that
is shorter than the usual typeset dash. Info reduces three hyphens to two for
display on the screen.@refill

To prevent a paragraph from being indented in the printed manual, put
the command @code{@@noindent} on a line by itself before the
paragraph.@refill

If you mark off a region of the Texinfo file with the @code{@@iftex}
and @w{@code{@@end iftex}} commands, that region will appear only in
the printed copy; in that region, you can use certain commands
borrowed from plain @TeX{} that you cannot use in Info.  Likewise, if
you mark off a region with the @code{@@ifinfo} and @code{@@end ifinfo}
commands, that region will appear only in the Info file; in that
region, you can use Info commands that you cannot use in @TeX{}.
Similarly for @code{@@ifhtml} and @code{@@end ifhtml}.
@xref{Conditionals}.

@cindex Tabs; don't use!
@quotation
@strong{Caution:} Do not use tabs in a Texinfo file!  @TeX{} uses
variable-width fonts, which means that it cannot predefine a tab to work
in all circumstances.  Consequently, @TeX{} treats tabs like single
spaces, and that is not what they look like.@refill

@noindent
To avoid this problem, Texinfo mode causes GNU Emacs to insert multiple
spaces when you press the @key{TAB} key.@refill

@noindent
Also, you can run @code{untabify} in Emacs to convert tabs in a region
to multiple spaces.@refill
@end quotation

@node Comments, Minimum, Conventions, Overview
@comment  node-name,  next,  previous,  up
@section Comments

You can write comments in a Texinfo file that will not appear in
either the Info file or the printed manual by using the
@code{@@comment} command (which may be abbreviated to @code{@@c}).
Such comments are for the person who reads the Texinfo file.  All the
text on a line that follows either @code{@@comment} or @code{@@c} is a
comment; the rest of the line does not appear in either the Info file
or the printed manual. (Often, you can write the @code{@@comment} or
@code{@@c} in the middle of a line, and only the text that follows after
the @code{@@comment} or @code{@@c} command does not appear; but some
commands, such as @code{@@settitle} and @code{@@setfilename}, work on a
whole line.  You cannot use @code{@@comment} or @code{@@c} in a line
beginning with such a command.)@refill
@cindex Comments
@findex comment
@findex c @r{(comment)}

You can write long stretches of text that will not appear in either
the Info file or the printed manual by using the @code{@@ignore} and
@code{@@end ignore} commands.  Write each of these commands on a line
of its own, starting each command at the beginning of the line.  Text
between these two commands does not appear in the processed output.
You can use @code{@@ignore} and @code{@@end ignore} for writing
comments.  Often, @code{@@ignore} and @code{@@end ignore} is used
to enclose a part of the copying permissions that applies to the
Texinfo source file of a document, but not to the Info or printed
version of the document.@refill
@cindex Ignored text
@cindex Unprocessed text
@findex ignore
@c !!! Perhaps include this comment about ignore and ifset:
@ignore
Text enclosed by @code{@@ignore} or by failing @code{@@ifset} or
@code{@@ifclear} conditions is ignored in the sense that it will not
contribute to the formatted output.  However, TeX and makeinfo must
still parse the ignored text, in order to understand when to
@emph{stop} ignoring text from the source file; that means that you
will still get error messages if you have invalid Texinfo markup
within ignored text.
@end ignore

@node Minimum, Six Parts, Comments, Overview
@comment  node-name,  next,  previous,  up
@section What a Texinfo File Must Have
@cindex Minimal Texinfo file (requirements)
@cindex Must have in Texinfo file
@cindex Required in Texinfo file
@cindex Texinfo file minimum

By convention, the names of Texinfo files end with one of the
extensions @file{.texinfo}, @file{.texi}, or @file{.tex}.  The longer
extension is preferred since it describes more clearly to a human
reader the nature of the file.  The shorter extensions are for
operating systems that cannot handle long file names.@refill

In order to be made into a printed manual and an Info file, a Texinfo
file @strong{must} begin with lines like this:@refill

@example
@group
\input texinfo
@@setfilename @var{info-file-name}
@@settitle @var{name-of-manual}
@end group
@end example

@noindent
The contents of the file follow this beginning, and then you @strong{must} end
a Texinfo file with a line like this:@refill

@example
@@bye
@end example

@findex input @r{(@TeX{} command)}
@noindent
The @samp{\input texinfo} line tells @TeX{} to use the
@file{texinfo.tex} file, which tells @TeX{} how to translate the Texinfo
@@-commands into @TeX{} typesetting commands.  (Note the use of the
backslash, @samp{\}; this is correct for @TeX{}.)  The
@samp{@@setfilename} line provides a name for the Info file and tells
@TeX{} to open auxiliary files.  The @samp{@@settitle} line specifies a
title for the page headers (or footers) of the printed manual.@refill

The @code{@@bye} line at the end of the file on a line of its own tells
the formatters that the file is ended and to stop formatting.@refill

Usually, you will not use quite such a spare format, but will include
mode setting and start-of-header and end-of-header lines at the
beginning of a Texinfo file, like this:@refill

@example
@group
\input texinfo   @@c -*-texinfo-*-
@@c %**start of header
@@setfilename @var{info-file-name}
@@settitle @var{name-of-manual}
@@c %**end of header
@end group
@end example

@noindent
In the first line, @samp{-*-texinfo-*-} causes Emacs to switch into
Texinfo mode when you edit the file.

The @code{@@c} lines which surround the @samp{@@setfilename} and
@samp{@@settitle} lines are optional, but you need them in order to
run @TeX{} or Info on just part of the file.  (@xref{Start of Header},
for more information.)@refill

Furthermore, you will usually provide a Texinfo file with a title
page, indices, and the like.  But the minimum, which can be useful
for short documents, is just the three lines at the beginning and the
one line at the end.@refill

@node Six Parts, Short Sample, Minimum, Overview
@comment  node-name,  next,  previous,  up
@section Six Parts of a Texinfo File

Generally, a Texinfo file contains more than the minimal
beginning and end---it usually contains six parts:@refill

@table @r
@item 1. Header
The @dfn{Header} names the file, tells @TeX{} which definitions' file to
use, and performs other ``housekeeping'' tasks.@refill

@item 2. Summary Description and Copyright
The @dfn{Summary Description and Copyright} segment describes the document
and contains the copyright notice and copying permissions for the Info
file.  The segment must be enclosed between @code{@@ifinfo} and
@code{@@end ifinfo} commands so that the formatters place it only in the Info
file.@refill

@item 3. Title and Copyright
The @dfn{Title and Copyright} segment contains the title and copyright pages
and copying permissions for the printed manual.  The segment must be
enclosed between @code{@@titlepage} and @code{@@end titlepage} commands.
The title and copyright page appear only in the printed @w{manual}.@refill

@item 4. `Top' Node and Master Menu
The @dfn{Master Menu} contains a complete menu of all the nodes in the whole
Info file.  It appears only in the Info file, in the `Top' node.@refill

@item 5. Body
The @dfn{Body} of the document may be structured like a traditional book or
encyclopedia or it may be free form.@refill

@item 6. End
The @dfn{End} contains commands for printing indices and generating
the table of contents, and the @code{@@bye} command on a line of its
own.@refill
@end table

@node Short Sample, Acknowledgements, Six Parts, Overview
@comment  node-name,  next,  previous,  up
@section A Short Sample Texinfo File
@cindex Sample Texinfo file

Here is a complete but very short Texinfo file, in 6 parts.  The first
three parts of the file, from @samp{\input texinfo} through to
@samp{@@end titlepage}, look more intimidating than they are.  Most of
the material is standard boilerplate; when you write a manual, simply
insert the names for your own manual in this segment. (@xref{Beginning a
File}.)@refill

@noindent
In the following, the sample text is @emph{indented}; comments on it are
not.  The complete file, without any comments, is shown in
@ref{Sample Texinfo File}.

@subheading Part 1: Header

@noindent
The header does not appear in either the Info file or the@*
printed output.  It sets various parameters, including the@*
name of the Info file and the title used in the header.

@example
@group
\input texinfo   @@c -*-texinfo-*-
@@c %**start of header
@@setfilename sample.info
@@settitle Sample Document
@@c %**end of header

@@setchapternewpage odd
@end group
@end example

@subheading Part 2: Summary Description and Copyright

@noindent
The summary description and copyright segment does not@*
appear in the printed document.

@example
@group
@@ifinfo
This is a short example of a complete Texinfo file.

Copyright @@copyright@{@} 1990 Free Software Foundation, Inc.
@@end ifinfo
@end group
@end example

@subheading Part 3: Titlepage and Copyright

@noindent
The titlepage segment does not appear in the Info file.

@example
@group
@@titlepage
@@sp 10
@@comment The title is printed in a large font.
@@center @@titlefont@{Sample Title@}
@end group

@group
@@c The following two commands start the copyright page.
@@page
@@vskip 0pt plus 1filll
Copyright @@copyright@{@} 1990 Free Software Foundation, Inc.
@@end titlepage
@end group
@end example

@subheading Part 4: `Top' Node and Master Menu

@noindent
The `Top' node contains the master menu for the Info file.@*
Since a printed manual uses a table of contents rather than@*
a menu, the master menu appears only in the Info file.

@example
@group
@@node    Top,       First Chapter, (dir),    (dir)
@@comment node-name, next,          previous, up
@end group
@end example

@example
@group
@@menu
* First Chapter::    The first chapter is the
                     only chapter in this sample.
* Concept Index::    This index has two entries.
@@end menu
@end group
@end example

@subheading Part 5:  The Body of the Document

@noindent
The body segment contains all the text of the document, but not the
indices or table of contents.  This example illustrates a node and a
chapter containing an enumerated list.@refill

@example
@group
@@node    First Chapter, Concept Index, Top,      Top
@@comment node-name,     next,          previous, up
@@chapter First Chapter
@@cindex Sample index entry
@end group

@group
This is the contents of the first chapter.
@@cindex Another sample index entry
@end group

@group
Here is a numbered list.

@@enumerate
@@item
This is the first item.

@@item
This is the second item.
@@end enumerate
@end group

@group
The @@code@{makeinfo@} and @@code@{texinfo-format-buffer@}
commands transform a Texinfo file such as this into
an Info file; and @@TeX@{@} typesets it for a printed
manual.
@end group
@end example

@subheading Part 6: The End of the Document

@noindent
The end segment contains commands both for generating an index in a node
and unnumbered chapter of its own and for generating the table of
contents; and it contains the @code{@@bye} command that marks the end of
the document.@refill

@example
@group
@@node    Concept Index,    ,  First Chapter, Top
@@comment node-name,    next,  previous,      up
@@unnumbered Concept Index
@end group

@group
@@printindex cp

@@contents
@@bye
@end group
@end example

@subheading The Results

Here is what the contents of the first chapter of the sample look like:

@sp 1
@need 700
@quotation
This is the contents of the first chapter.

Here is a numbered list.

@enumerate
@item
This is the first item.

@item
This is the second item.
@end enumerate

The @code{makeinfo} and @code{texinfo-format-buffer}
commands transform a Texinfo file such as this into
an Info file; and @TeX{} typesets it for a printed
manual.
@end quotation

@node Acknowledgements, , Short Sample, Overview
@comment  node-name,  next,  previous,  up
@section Acknowledgements

@cindex Stallman, Richard M.
@cindex Chassell, Robert J.
@cindex Berry, Karl
Richard M.@: Stallman wrote Edition 1.0 of this manual.  @w{Robert J.@:
Chassell} revised and extended it, starting with Edition 1.1.  Karl
Berry made updates for the Texinfo 3.8 and subsequent releases, starting
with Edition 2.22.

@cindex Pinard, Fran@,{c}ois
@cindex Zuhn, David D.
@cindex Weisshaus, Melissa
Our thanks go out to all who helped improve this work, particularly to
Fran@,{c}ois Pinard and @w{David D.@: Zuhn}, who tirelessly recorded and
reported mistakes and obscurities; our special thanks go to Melissa
Weisshaus for her frequent and often tedious reviews of nearly similar
editions.  Our mistakes are our own.

Please send suggestions and corrections to:

@example
@group
@r{Internet address:}
    bug-texinfo@@prep.ai.mit.edu
@end group
@end example

@noindent
Please include the manual's edition number and update date in your messages.

@node Texinfo Mode, Beginning a File, Overview, Top
@comment  node-name,  next,  previous,  up
@chapter Using Texinfo Mode
@cindex Texinfo mode
@cindex Mode, using Texinfo
@cindex GNU Emacs
@cindex Emacs

You may edit a Texinfo file with any text editor you choose.  A Texinfo
file is no different from any other @sc{ascii} file.  However, GNU Emacs
comes with a special mode, called Texinfo
mode, that provides  Emacs commands and tools to help ease your work.@refill

This chapter describes features of GNU Emacs' Texinfo mode but not any
features of the Texinfo formatting language.  If you are reading this
manual straight through from the beginning, you may want to skim through
this chapter briefly and come back to it after reading succeeding
chapters which describe the Texinfo formatting language in
detail.@refill

@menu
* Texinfo Mode Overview::       How Texinfo mode can help you.
* Emacs Editing::               Texinfo mode adds to GNU Emacs' general
                                  purpose editing features.
* Inserting::                   How to insert frequently used @@-commands.
* Showing the Structure::       How to show the structure of a file.
* Updating Nodes and Menus::    How to update or create new nodes and menus.
* Info Formatting::             How to format for Info.
* Printing::                    How to format and print part or all of a file.
* Texinfo Mode Summary::        Summary of all the Texinfo mode commands.
@end menu

@node Texinfo Mode Overview, Emacs Editing, Texinfo Mode, Texinfo Mode
@ifinfo
@heading Texinfo Mode Overview
@end ifinfo

Texinfo mode provides special features for working with Texinfo
files:@refill

@itemize @bullet
@item
Insert frequently used @@-commands. @refill

@item
Automatically create @code{@@node} lines.

@item
Show the structure of a Texinfo source file.@refill

@item
Automatically create or update the `Next',@*
`Previous', and `Up' pointers of a node.

@item
Automatically create or update menus.@refill

@item
Automatically create a master menu.@refill

@item
Format a part or all of a file for Info.@refill

@item
Typeset and print part or all of a file.@refill
@end itemize

Perhaps the two most helpful features are those for inserting frequently
used @@-commands and for creating node pointers and menus.@refill

@node Emacs Editing, Inserting, Texinfo Mode Overview, Texinfo Mode
@section The Usual GNU Emacs Editing Commands

In most cases, the usual Text mode commands work the same in Texinfo
mode as they do in Text mode.  Texinfo mode adds new editing commands
and tools to GNU Emacs' general purpose editing features.  The major
difference concerns filling.  In Texinfo mode, the paragraph
separation variable and syntax table are redefined so that Texinfo
commands that should be on lines of their own are not inadvertently
included in paragraphs.  Thus, the @kbd{M-q} (@code{fill-paragraph})
command will refill a paragraph but not mix an indexing command on a
line adjacent to it into the paragraph.@refill

In addition, Texinfo mode sets the @code{page-delimiter} variable to
the value of @code{texinfo-chapter-level-regexp}; by default, this is
a regular expression matching the commands for chapters and their
equivalents, such as appendices.  With this value for the page
delimiter, you can jump from chapter title to chapter title with the
@kbd{C-x ]} (@code{forward-page}) and @kbd{C-x [}
(@code{backward-page}) commands and narrow to a chapter with the
@kbd{C-x p} (@code{narrow-to-page}) command.  (@xref{Pages, , ,emacs,
The GNU Emacs Manual}, for details about the page commands.)@refill

You may name a Texinfo file however you wish, but the convention is to
end a Texinfo file name with one of the three extensions
@file{.texinfo}, @file{.texi}, or @file{.tex}.  A longer extension is
preferred, since it is explicit, but a shorter extension may be
necessary for operating systems that limit the length of file names.
GNU Emacs automatically enters Texinfo mode when you visit a file with
a @file{.texinfo} or  @file{.texi}
extension.  Also, Emacs switches to Texinfo mode
when you visit a
file that has @samp{-*-texinfo-*-} in its first line.  If ever you are
in another mode and wish to switch to Texinfo mode, type @code{M-x
texinfo-mode}.@refill

Like all other Emacs features, you can customize or enhance Texinfo
mode as you wish.  In particular, the keybindings are very easy to
change.  The keybindings described here are the default or standard
ones.@refill

@node Inserting, Showing the Structure, Emacs Editing, Texinfo Mode
@comment  node-name,  next,  previous,  up
@section Inserting Frequently Used Commands
@cindex Inserting frequently used commands
@cindex Frequently used commands, inserting
@cindex Commands, inserting them

Texinfo mode provides commands to insert various frequently used
@@-commands into the buffer.  You can use these commands to save
keystrokes.@refill

The insert commands are invoked by typing @kbd{C-c} twice and then the
first letter of the @@-command:@refill

@table @kbd
@item  C-c C-c c
@itemx M-x texinfo-insert-@@code
@findex texinfo-insert-@@code
Insert @code{@@code@{@}} and put the
cursor between the braces.@refill

@item  C-c C-c d
@itemx M-x texinfo-insert-@@dfn
@findex texinfo-insert-@@dfn
Insert @code{@@dfn@{@}} and put the
cursor between the braces.@refill

@item  C-c C-c e
@itemx M-x texinfo-insert-@@end
@findex texinfo-insert-@@end
Insert @code{@@end} and attempt to insert the correct following word,
such as @samp{example} or @samp{table}.  (This command does not handle
nested lists correctly, but inserts the word appropriate to the
immediately preceding list.)@refill

@item  C-c C-c i
@itemx M-x texinfo-insert-@@item
@findex texinfo-insert-@@item
Insert @code{@@item} and put the
cursor at the beginning of the next line.@refill

@item  C-c C-c k
@itemx M-x texinfo-insert-@@kbd
@findex texinfo-insert-@@kbd
Insert @code{@@kbd@{@}} and put the
cursor between the braces.@refill

@item  C-c C-c n
@itemx M-x texinfo-insert-@@node
@findex texinfo-insert-@@node
Insert @code{@@node} and a comment line
listing the sequence for the `Next',
`Previous', and `Up' nodes.
Leave point after the @code{@@node}.@refill

@item  C-c C-c o
@itemx M-x texinfo-insert-@@noindent
@findex texinfo-insert-@@noindent
Insert @code{@@noindent} and put the
cursor at the beginning of the next line.@refill

@item  C-c C-c s
@itemx M-x texinfo-insert-@@samp
@findex texinfo-insert-@@samp
Insert @code{@@samp@{@}} and put the
cursor between the braces.@refill

@item  C-c C-c t
@itemx M-x texinfo-insert-@@table
@findex texinfo-insert-@@table
Insert @code{@@table} followed by a @key{SPC}
and leave the cursor after the @key{SPC}.@refill

@item  C-c C-c v
@itemx M-x texinfo-insert-@@var
@findex texinfo-insert-@@var
Insert @code{@@var@{@}} and put the
cursor between the braces.@refill

@item  C-c C-c x
@itemx M-x texinfo-insert-@@example
@findex texinfo-insert-@@example
Insert @code{@@example} and put the
cursor at the beginning of the next line.@refill

@c M-@{  was the binding for texinfo-insert-braces;
@c in Emacs 19, backward-paragraph will take this binding.
@item C-c C-c @{
@itemx M-x texinfo-insert-braces
@findex texinfo-insert-braces
Insert @code{@{@}} and put the cursor between the braces.@refill

@item C-c C-c @}
@itemx C-c C-c ]
@itemx M-x up-list
@findex up-list
Move from between a pair of braces forward past the closing brace.
Typing @kbd{C-c C-c ]} is easier than typing @kbd{C-c C-c @}}, which
is, however, more mnemonic; hence the two keybindings.  (Also, you can
move out from between braces by typing @kbd{C-f}.)@refill
@end table

To put a command such as @w{@code{@@code@{@dots{}@}}} around an
@emph{existing} word, position the cursor in front of the word and type
@kbd{C-u 1 C-c C-c c}.  This makes it easy to edit existing plain text.
The value of the prefix argument tells Emacs how many words following
point to include between braces---1 for one word, 2 for two words, and
so on.  Use a negative argument to enclose the previous word or words.
If you do not specify a prefix argument, Emacs inserts the @@-command
string and positions the cursor between the braces.  This feature works
only for those @@-commands that operate on a word or words within one
line, such as @code{@@kbd} and @code{@@var}.@refill

This set of insert commands was created after analyzing the frequency
with which different @@-commands are used in the @cite{GNU Emacs
Manual} and the @cite{GDB Manual}.  If you wish to add your own insert
commands, you can bind a keyboard macro to a key, use abbreviations,
or extend the code in @file{texinfo.el}.@refill

@findex texinfo-start-menu-description
@cindex Menu description, start
@cindex Description for menu, start
@kbd{C-c C-c C-d} (@code{texinfo-start-menu-description}) is an insert
command that works differently from the other insert commands.  It
inserts a node's section or chapter title in the space for the
description in a menu entry line.  (A menu entry has three parts, the
entry name, the node name, and the description.  Only the node name is
required, but a description helps explain what the node is about.
@xref{Menu Parts, , The Parts of a Menu}.)@refill

To use @code{texinfo-start-menu-description}, position point in a menu
entry line and type @kbd{C-c C-c C-d}.  The command looks for and copies
the title that goes with the node name, and inserts the title as a
description; it positions point at beginning of the inserted text so you
can edit it.  The function does not insert the title if the menu entry
line already contains a description.@refill

This command is only an aid to writing descriptions; it does not do the
whole job.  You must edit the inserted text since a title tends to use
the same words as a node name but a useful description uses different
words.@refill

@node Showing the Structure, Updating Nodes and Menus, Inserting, Texinfo Mode
@comment  node-name,  next,  previous,  up
@section Showing the Section Structure of a File
@cindex Showing the section structure of a file
@cindex Section structure of a file, showing it
@cindex Structure of a file, showing it
@cindex Outline of file structure, showing it
@cindex Contents-like outline of file structure
@cindex File section structure, showing it
@cindex Texinfo file section structure, showing it

You can show the section structure of a Texinfo file by using the
@kbd{C-c C-s} command (@code{texinfo-show-structure}).  This command
shows the section structure of a Texinfo file by listing the lines
that begin with the @@-commands for @code{@@chapter},
@code{@@section}, and the like.  It constructs what amounts
to a table of contents.  These lines are displayed in another buffer
called the @samp{*Occur*} buffer.  In that buffer, you can position
the cursor over one of the lines and use the @kbd{C-c C-c} command
(@code{occur-mode-goto-occurrence}), to jump to the corresponding spot
in the Texinfo file.@refill

@table @kbd
@item  C-c C-s
@itemx M-x texinfo-show-structure
@findex texinfo-show-structure
Show the @code{@@chapter}, @code{@@section}, and such lines of a
Texinfo file.@refill

@item  C-c C-c
@itemx M-x occur-mode-goto-occurrence
@findex occur-mode-goto-occurrence
Go to the line in the Texinfo file corresponding to the line under the
cursor in the @file{*Occur*} buffer.@refill
@end table

If you call @code{texinfo-show-structure} with a prefix argument by
typing @w{@kbd{C-u C-c C-s}}, it will list not only those lines with the
@@-commands for @code{@@chapter}, @code{@@section}, and the like,
but also the @code{@@node} lines.  (This is how the
@code{texinfo-show-structure} command worked without an argument in
the first version of Texinfo.  It was changed because @code{@@node}
lines clutter up the @samp{*Occur*} buffer and are usually not
needed.)  You can use @code{texinfo-show-structure} with a prefix
argument to check whether the `Next', `Previous', and `Up' pointers of
an @code{@@node} line are correct.@refill

Often, when you are working on a manual, you will be interested only
in the structure of the current chapter.  In this case, you can mark
off the region of the buffer that you are interested in by using the
@kbd{C-x n n} (@code{narrow-to-region}) command and
@code{texinfo-show-structure} will work on only that region.  To see
the whole buffer again, use @w{@kbd{C-x n w}} (@code{widen}).
(@xref{Narrowing, , , emacs, The GNU Emacs Manual}, for more
information about the narrowing commands.)@refill

@vindex page-delimiter
@cindex Page delimiter in Texinfo mode
In addition to providing the @code{texinfo-show-structure} command,
Texinfo mode sets the value of the page delimiter variable to match
the chapter-level @@-commands.  This enables you to use the @kbd{C-x
]} (@code{forward-page}) and @kbd{C-x [} (@code{backward-page})
commands to move forward and backward by chapter, and to use the
@kbd{C-x p} (@code{narrow-to-page}) command to narrow to a chapter.
@xref{Pages, , , emacs, The GNU Emacs Manual}, for more information
about the page commands.@refill

@node Updating Nodes and Menus, Info Formatting, Showing the Structure, Texinfo Mode
@comment  node-name,  next,  previous,  up
@section Updating Nodes and Menus
@cindex Updating nodes and menus
@cindex Create nodes, menus automatically
@cindex Insert nodes, menus automatically
@cindex Automatically insert nodes, menus

Texinfo mode provides commands for automatically creating or updating
menus and node pointers.  The commands are called ``update'' commands
because their most frequent use is for updating a Texinfo file after
you have worked on it; but you can use them to insert the `Next',
`Previous', and `Up' pointers into an @code{@@node} line that has none and to
create menus in a file that has none.@refill

If you do not use the updating commands, you need to write menus and
node pointers by hand, which is a tedious task.@refill

@menu
* Updating Commands::           Five major updating commands.
* Updating Requirements::       How to structure a Texinfo file for
                                  using the updating command.
* Other Updating Commands::     How to indent descriptions, insert
                                  missing nodes lines, and update
                                  nodes in sequence.
@end menu

@node Updating Commands, Updating Requirements, Updating Nodes and Menus, Updating Nodes and Menus
@ifinfo
@subheading The Updating Commands
@end ifinfo

You can use the updating commands@refill

@itemize @bullet
@item
to insert or update the `Next', `Previous', and `Up' pointers of a
node,@refill

@item
to insert or update the menu for a section, and@refill

@item
to create a master menu for a Texinfo source file.@refill
@end itemize

You can also use the commands to update all the nodes and menus in a
region or in a whole Texinfo file.@refill

The updating commands work only with conventional Texinfo files, which
are structured hierarchically like books.  In such files, a structuring
command line must follow closely after each @code{@@node} line, except
for the `Top' @code{@@node} line.  (A @dfn{structuring command line} is
a line beginning with @code{@@chapter}, @code{@@section}, or other
similar command.)

You can write the structuring command line on the line that follows
immediately after an @code{@@node} line or else on the line that
follows after a single @code{@@comment} line or a single
@code{@@ifinfo} line.  You cannot interpose more than one line between
the @code{@@node} line and the structuring command line; and you may
interpose only an @code{@@comment} line or an @code{@@ifinfo} line.

Commands which work on a whole buffer require that the `Top' node be
followed by a node with an @code{@@chapter} or equivalent-level command.
Note that the menu updating commands will not create a main or master
menu for a Texinfo file that has only @code{@@chapter}-level nodes!  The
menu updating commands only create menus @emph{within} nodes for lower level
nodes.  To create a menu of chapters, you must provide a `Top'
node.@refill

The menu updating commands remove menu entries that refer to other Info
files since they do not refer to nodes within the current buffer.  This
is a deficiency.  Rather than use menu entries, you can use cross
references to refer to other Info files.  None of the updating commands
affect cross references.@refill

Texinfo mode has five updating commands that are used most often: two
are for updating the node pointers or menu of a single node (or a
region); two are for updating every node pointer and menu in a file;
and one, the @code{texinfo-master-menu} command, is for creating a
master menu for a complete file, and optionally, for updating every
node and menu in the whole Texinfo file.@refill

The @code{texinfo-master-menu} command is the primary command:@refill

@table @kbd
@item C-c C-u m
@itemx M-x texinfo-master-menu
@findex texinfo-master-menu
Create or update a master menu that includes all the other menus
(incorporating the descriptions from pre-existing menus, if
any).@refill

With an argument (prefix argument, @kbd{C-u,} if interactive), first create or
update all the nodes and all the regular menus in the buffer before
constructing the master menu.  (@xref{The Top Node, , The Top Node and
Master Menu}, for more about a master menu.)@refill

For @code{texinfo-master-menu} to work, the Texinfo file must have a
`Top' node and at least one subsequent node.@refill

After extensively editing a Texinfo file, you can type the following:

@example
C-u M-x texinfo-master-menu
@exdent or
C-u C-c C-u m
@end example

@noindent
This updates all the nodes and menus completely and all at once.@refill
@end table

The other major updating commands do smaller jobs and are designed for
the person  who updates nodes and menus as he or she writes a Texinfo
file.@refill

@need 1000
The commands are:@refill

@table @kbd
@item C-c C-u C-n
@itemx M-x texinfo-update-node
@findex texinfo-update-node
Insert the `Next', `Previous', and `Up' pointers for the node that point is
within (i.e., for the @code{@@node} line preceding point).  If the
@code{@@node} line has pre-existing `Next', `Previous', or `Up'
pointers in it, the old pointers are removed and new ones inserted.
With an argument (prefix argument, @kbd{C-u}, if interactive), this command
updates all @code{@@node} lines in the region (which is the text
between point and mark).@refill

@item C-c C-u C-m
@itemx M-x texinfo-make-menu
@findex texinfo-make-menu
Create or update the menu in the node that point is within.
With an argument (@kbd{C-u} as prefix argument, if
interactive), the command makes or updates menus for the
nodes which are either within or a part of the
region.@refill

Whenever @code{texinfo-make-menu} updates an existing menu, the
descriptions from that menu are incorporated into the new menu.  This
is done by copying descriptions from the existing menu to the entries
in the new menu that have the same node names.  If the node names are
different, the descriptions are not copied to the new menu.@refill

@item C-c C-u C-e
@itemx M-x texinfo-every-node-update
@findex texinfo-every-node-update
Insert or update the `Next', `Previous', and `Up' pointers for every
node in the buffer.@refill

@item C-c C-u C-a
@itemx M-x texinfo-all-menus-update
@findex texinfo-all-menus-update
Create or update all the menus in the buffer.  With an argument
(@kbd{C-u} as prefix argument, if interactive), first insert
or update all the node
pointers before working on the menus.@refill

If a master menu exists, the @code{texinfo-all-menus-update} command
updates it; but the command does not create a new master menu if none
already exists.  (Use the @code{texinfo-master-menu} command for
that.)@refill

When working on a document that does not merit a master menu, you can
type the following:

@example
C-u C-c C-u C-a
@exdent or
C-u M-x texinfo-all-menus-update
@end example

@noindent
This updates all the nodes and menus.@refill
@end table

The @code{texinfo-column-for-description} variable specifies the
column to which menu descriptions are indented.  By default, the value
is 32 although it is often useful to reduce it to as low as 24.  You
can set the variable with the @kbd{M-x edit-options} command
(@pxref{Edit Options, , Editing Variable Values, emacs, The GNU Emacs
Manual}) or with the @kbd{M-x set-variable} command (@pxref{Examining,
, Examining and Setting Variables, emacs, The GNU Emacs
Manual}).@refill

Also, the @code{texinfo-indent-menu-description} command may be used to
indent existing menu descriptions to a specified column.  Finally, if
you wish, you can use the @code{texinfo-insert-node-lines} command to
insert missing @code{@@node} lines into a file.  (@xref{Other Updating
Commands}, for more information.)@refill

@node Updating Requirements, Other Updating Commands, Updating Commands, Updating Nodes and Menus
@comment  node-name,  next,  previous,  up
@subsection Updating Requirements
@cindex Updating requirements
@cindex Requirements for updating commands

To use the updating commands, you must organize the Texinfo file
hierarchically with chapters, sections, subsections, and the like.
When you construct the hierarchy of the manual, do not `jump down'
more than one level at a time: you can follow the `Top' node with a
chapter, but not with a section; you can follow a chapter with a
section, but not with a subsection.  However, you may `jump up' any
number of levels at one time---for example, from a subsection to a
chapter.@refill

Each @code{@@node} line, with the exception of the line for the `Top'
node, must be followed by a line with a structuring command such as
@code{@@chapter}, @code{@@section}, or
@code{@@unnumberedsubsec}.@refill

Each @code{@@node} line/structuring-command line combination
must look either like this:@refill

@example
@group
@@node     Comments,  Minimum, Conventions, Overview
@@comment  node-name, next,    previous,    up
@@section Comments
@end group
@end example

or like this (without the @code{@@comment} line):

@example
@group
@@node Comments, Minimum, Conventions, Overview
@@section Comments
@end group
@end example

@noindent
In this example, `Comments' is the name of both the node and the
section.  The next node is called `Minimum' and the previous node is
called `Conventions'.  The `Comments' section is within the `Overview'
node, which is specified by the `Up' pointer.  (Instead of an
@code{@@comment} line, you can write an @code{@@ifinfo} line.)@refill

If a file has a `Top' node, it must be called @samp{top} or @samp{Top}
and be the first node in the file.@refill

The menu updating commands create a menu of sections within a chapter,
a menu of subsections within a section, and so on.  This means that
you must have a `Top' node if you want a menu of chapters.@refill

Incidentally, the @code{makeinfo} command will create an Info file for
a hierarchically organized Texinfo file that lacks `Next', `Previous'
and `Up' pointers.  Thus, if you can be sure that your Texinfo file
will be formatted with @code{makeinfo}, you have no need for the
`update node' commands.  (@xref{Create an Info File, , Creating an
Info File}, for more information about @code{makeinfo}.)  However,
both @code{makeinfo} and the @code{texinfo-format-@dots{}} commands
require that you insert menus in the file.@refill

@node Other Updating Commands, , Updating Requirements, Updating Nodes and Menus
@comment  node-name,  next,  previous,  up
@subsection Other Updating Commands

In addition to the five major updating commands, Texinfo mode
possesses several less frequently used updating commands:@refill

@table @kbd
@item M-x texinfo-insert-node-lines
@findex texinfo-insert-node-lines
Insert @code{@@node} lines before the @code{@@chapter},
@code{@@section}, and other sectioning commands wherever they are
missing throughout a region in a Texinfo file.@refill

With an argument (@kbd{C-u} as prefix argument, if interactive), the
@code{texinfo-insert-node-lines} command not only inserts
@code{@@node} lines but also inserts the chapter or section titles as
the names of the corresponding nodes.  In addition, it inserts the
titles as node names in pre-existing @code{@@node} lines that lack
names.  Since node names should be more concise than section or
chapter titles, you must manually edit node names so inserted.@refill

For example, the following marks a whole buffer as a region and inserts
@code{@@node} lines and titles throughout:@refill

@example
C-x h C-u M-x texinfo-insert-node-lines
@end example

(Note that this command inserts titles as node names in @code{@@node}
lines; the @code{texinfo-start-menu-description} command
(@pxref{Inserting, Inserting Frequently Used Commands}) inserts titles
as descriptions in menu entries, a different action.  However, in both
cases, you need to edit the inserted text.)@refill

@item M-x texinfo-multiple-files-update
@findex texinfo-multiple-files-update @r{(in brief)}
Update nodes and menus in a document built from several separate files.
With @kbd{C-u} as a prefix argument, create and insert a master menu in
the outer file.  With a numeric prefix argument, such as @kbd{C-u 2}, first
update all the menus and all the `Next', `Previous', and `Up' pointers
of all the included files before creating and inserting a master menu in
the outer file.  The @code{texinfo-multiple-files-update} command is
described in the appendix on @code{@@include} files.
@ifinfo
@xref{texinfo-multiple-files-update}.@refill
@end ifinfo
@iftex
@xref{texinfo-multiple-files-update, ,
@code{texinfo-multiple-files-update}}.@refill
@end iftex

@item M-x texinfo-indent-menu-description
@findex texinfo-indent-menu-description
Indent every description in the menu following point to the specified
column.  You can use this command to give yourself more space for
descriptions.  With an argument (@kbd{C-u} as prefix argument, if
interactive), the @code{texinfo-indent-menu-description} command indents
every description in every menu in the region.  However, this command
does not indent the second and subsequent lines of a multi-line
description.@refill

@item M-x texinfo-sequential-node-update
@findex texinfo-sequential-node-update
Insert the names of the nodes immediately following and preceding the
current node as the `Next' or `Previous' pointers regardless of those
nodes' hierarchical level.  This means that the `Next' node of a
subsection may well be the next chapter.  Sequentially ordered nodes are
useful for novels and other documents that you read through
sequentially.  (However, in Info, the @code{g* @key{RET}} command lets
you look through the file sequentially, so sequentially ordered nodes
are not strictly necessary.)  With an argument (prefix argument, if
interactive), the @code{texinfo-sequential-node-update} command
sequentially updates all the nodes in the region.@refill
@end table

@node Info Formatting, Printing, Updating Nodes and Menus, Texinfo Mode
@comment  node-name,  next,  previous,  up
@section Formatting for Info
@cindex Formatting for Info
@cindex Running an Info formatter
@cindex Info formatting

Texinfo mode provides several commands for formatting part or all of a
Texinfo file for Info.  Often, when you are writing a document, you
want to format only part of a file---that is, a region.@refill

You can use either the @code{texinfo-format-region} or the
@code{makeinfo-region} command to format a region:@refill

@table @kbd
@findex texinfo-format-region
@item  C-c C-e C-r
@itemx M-x texinfo-format-region
@itemx C-c C-m C-r
@itemx M-x makeinfo-region
Format the current region for Info.@refill
@end table

You can use either the @code{texinfo-format-buffer} or the
@code{makeinfo-buffer} command to format a whole buffer:@refill

@table @kbd
@findex texinfo-format-buffer
@item  C-c C-e C-b
@itemx M-x texinfo-format-buffer
@itemx C-c C-m C-b
@itemx M-x makeinfo-buffer
Format the current buffer for Info.@refill
@end table

@need 1000
For example, after writing a Texinfo file, you can type the following:

@example
C-u C-c C-u m
@exdent or
C-u M-x texinfo-master-menu
@end example

@noindent
This updates all the nodes and menus.  Then type the following to create
an Info file:

@example
C-c C-m C-b
@exdent or
M-x makeinfo-buffer
@end example

For @TeX{} or the Info formatting commands to work, the file @emph{must}
include a line that has @code{@@setfilename} in its header.@refill

@xref{Create an Info File}, for details about Info formatting.@refill

@node Printing, Texinfo Mode Summary, Info Formatting, Texinfo Mode
@comment node-name,  next,  previous,  up
@section Formatting and Printing
@cindex Formatting for printing
@cindex Printing a region or buffer
@cindex Region formatting and printing
@cindex Buffer formatting and printing
@cindex Part of file formatting and printing

Typesetting and printing a Texinfo file is a multi-step process in which
you first create a file for printing (called a @sc{dvi} file), and then
print the file.  Optionally, you may also create indices.  To do this,
you must run the @code{texindex} command after first running the
@code{tex} typesetting command; and then you must run the @code{tex}
command again.  Or else run the @code{texi2dvi} command which
automatically creates indices as needed.@refill

Often, when you are writing a document, you want to typeset and print
only part of a file to see what it will look like.  You can use the
@code{texinfo-tex-region} and related commands for this purpose.  Use
the @code{texinfo-tex-buffer} command to format all of a
buffer.@refill

@table @kbd
@item  C-c C-t C-b
@itemx M-x texinfo-tex-buffer
@findex texinfo-tex-buffer
Run @code{texi2dvi} on the buffer.  In addition to running @TeX{} on the
buffer, this command automatically creates or updates indices as
needed.@refill

@item  C-c C-t C-r
@itemx M-x texinfo-tex-region
@findex texinfo-tex-region
Run @TeX{} on the region.@refill

@item C-c C-t C-i
@itemx M-x texinfo-texindex
Run @code{texindex} to sort the indices of a Texinfo file formatted with
@code{texinfo-tex-region}.  The @code{texinfo-tex-region} command does
not run @code{texindex} automatically; it only runs the @code{tex}
typesetting command.  You must run the @code{texinfo-tex-region} command
a second time after sorting the raw index files with the @code{texindex}
command.  (Usually, you do not format an index when you format a region,
only when you format a buffer.  Now that the @code{texi2dvi} command
exists, there is no little need for this command.)@refill

@item C-c C-t C-p
@itemx M-x texinfo-tex-print
@findex texinfo-tex-print
Print the file (or the part of the file) previously formatted with
@code{texinfo-tex-buffer} or @code{texinfo-tex-region}.@refill
@end table

For @code{texinfo-tex-region} or @code{texinfo-tex-buffer} to work, the
file @emph{must} start with a @samp{\input texinfo} line and must
include an @code{@@settitle} line.  The file must end with @code{@@bye}
on a line by itself.  (When you use @code{texinfo-tex-region}, you must
surround the @code{@@settitle} line with start-of-header and
end-of-header lines.)@refill

@xref{Format/Print Hardcopy}, for a description of the other @TeX{} related
commands, such as @code{tex-show-print-queue}.@refill

@node Texinfo Mode Summary, , Printing, Texinfo Mode
@comment  node-name,  next,  previous,  up
@section Texinfo Mode Summary

In Texinfo mode, each set of commands has default keybindings that
begin with the same keys.  All the commands that are custom-created
for Texinfo mode begin with @kbd{C-c}.  The keys are somewhat
mnemonic.@refill

@subheading Insert Commands

The insert commands are invoked by typing @kbd{C-c} twice and then the
first letter of the @@-command to be inserted.  (It might make more
sense mnemonically to use @kbd{C-c C-i}, for `custom insert', but
@kbd{C-c C-c} is quick to type.)@refill

@example
C-c C-c c       @r{Insert} @samp{@@code}.
C-c C-c d       @r{Insert} @samp{@@dfn}.
C-c C-c e       @r{Insert} @samp{@@end}.
C-c C-c i       @r{Insert} @samp{@@item}.
C-c C-c n       @r{Insert} @samp{@@node}.
C-c C-c s       @r{Insert} @samp{@@samp}.
C-c C-c v       @r{Insert} @samp{@@var}.
C-c C-c @{       @r{Insert braces.}
C-c C-c ]
C-c C-c @}       @r{Move out of enclosing braces.}

@group
C-c C-c C-d     @r{Insert a node's section title}
                @r{in the space for the description}
                @r{in a menu entry line.}
@end group
@end example

@subheading Show Structure

The @code{texinfo-show-structure} command is often used within a
narrowed region.@refill

@example
C-c C-s         @r{List all the headings.}
@end example

@subheading The Master Update Command

The @code{texinfo-master-menu} command creates a master menu; and can
be used to update every node and menu in a file as well.@refill

@example
@group
C-c C-u m
M-x texinfo-master-menu
                @r{Create or update a master menu.}
@end group

@group
C-u C-c C-u m   @r{With @kbd{C-u} as a prefix argument, first}
                @r{create or update all nodes and regular}
                @r{menus, and then create a master menu.}
@end group
@end example

@subheading Update Pointers

The update pointer commands are invoked by typing @kbd{C-c C-u} and
then either @kbd{C-n} for @code{texinfo-update-node} or @kbd{C-e} for
@code{texinfo-every-node-update}.@refill

@example
C-c C-u C-n     @r{Update a node.}
C-c C-u C-e     @r{Update every node in the buffer.}
@end example

@subheading Update Menus

Invoke the  update menu commands by typing @kbd{C-c C-u}
and then either @kbd{C-m} for @code{texinfo-make-menu} or
@kbd{C-a} for @code{texinfo-all-menus-update}.  To update
both nodes and menus at the same time, precede @kbd{C-c C-u
C-a} with @kbd{C-u}.@refill

@example
C-c C-u C-m     @r{Make or update a menu.}

@group
C-c C-u C-a     @r{Make or update all}
                @r{menus in a buffer.}
@end group

@group
C-u C-c C-u C-a @r{With @kbd{C-u} as a prefix argument,}
                @r{first create or update all nodes and}
                @r{then create or update all menus.}
@end group
@end example

@subheading Format for Info

The Info formatting commands that are written in Emacs Lisp are
invoked by typing @kbd{C-c C-e} and then either @kbd{C-r} for a region
or @kbd{C-b} for the whole buffer.@refill

The Info formatting commands that are written in C and based on the
@code{makeinfo} program are invoked by typing @kbd{C-c C-m} and then
either @kbd{C-r} for a region or @kbd{C-b} for the whole buffer.@refill

@need 800
@noindent
Use the @code{texinfo-format@dots{}} commands:

@example
@group
C-c C-e C-r     @r{Format the region.}
C-c C-e C-b     @r{Format the buffer.}
@end group
@end example

@need 750
@noindent
Use @code{makeinfo}:

@example
C-c C-m C-r     @r{Format the region.}
C-c C-m C-b     @r{Format the buffer.}
C-c C-m C-l     @r{Recenter the @code{makeinfo} output buffer.}
C-c C-m C-k     @r{Kill the @code{makeinfo} formatting job.}
@end example

@subheading Typeset and Print

The @TeX{} typesetting and printing commands are invoked by typing
@kbd{C-c C-t} and then another control command: @kbd{C-r} for
@code{texinfo-tex-region}, @kbd{C-b} for @code{texinfo-tex-buffer},
and so on.@refill

@example
C-c C-t C-r     @r{Run @TeX{} on the region.}
C-c C-t C-b     @r{Run} @code{texi2dvi} @r{on the buffer.}
C-c C-t C-i     @r{Run} @code{texindex}.
C-c C-t C-p     @r{Print the @sc{dvi} file.}
C-c C-t C-q     @r{Show the print queue.}
C-c C-t C-d     @r{Delete a job from the print queue.}
C-c C-t C-k     @r{Kill the current @TeX{} formatting job.}
C-c C-t C-x     @r{Quit a currently stopped @TeX{} formatting job.}
C-c C-t C-l     @r{Recenter the output buffer.}
@end example

@subheading Other Updating Commands

The `other updating commands' do not have standard keybindings because
they are rarely used.

@example
@group
M-x texinfo-insert-node-lines
                @r{Insert missing @code{@@node} lines in region.}
                @r{With @kbd{C-u} as a prefix argument,}
                @r{use section titles as node names.}
@end group

@group
M-x texinfo-multiple-files-update
                @r{Update a multi-file document.}
                @r{With @kbd{C-u 2} as a prefix argument,}
                @r{create or update all nodes and menus}
                @r{in all included files first.}
@end group

@group
M-x texinfo-indent-menu-description
                @r{Indent descriptions.}
@end group

@group
M-x texinfo-sequential-node-update
                @r{Insert node pointers in strict sequence.}
@end group
@end example

@node Beginning a File, Ending a File, Texinfo Mode, Top
@comment  node-name,  next,  previous,  up
@chapter Beginning a Texinfo File
@cindex Beginning a Texinfo file
@cindex Texinfo file beginning
@cindex File beginning

Certain pieces of information must be provided at the beginning of a
Texinfo file, such as the name of the file and the title of the
document.@refill

@menu
* Four Parts::                  Four parts begin a Texinfo file.
* Sample Beginning::            Here is a sample beginning for a Texinfo file.
* Header::                      The very beginning of a Texinfo file.
* Info Summary and Permissions::  Summary and copying permissions for Info.
* Titlepage & Copyright Page::  Creating the title and copyright pages.
* The Top Node::                Creating the `Top' node and master menu.
* Software Copying Permissions::  Ensure that you and others continue to
                                  have the right to use and share software.
@end menu

@node Four Parts, Sample Beginning, Beginning a File, Beginning a File
@ifinfo
@heading Four Parts Begin a File
@end ifinfo

Generally, the beginning of a Texinfo file has four parts:@refill

@enumerate
@item
The header, delimited by special comment lines, that includes the
commands for naming the Texinfo file and telling @TeX{} what
definitions' file to use when processing the Texinfo file.@refill

@item
A short statement of what the file is about, with a copyright notice
and copying permissions.  This is enclosed in @code{@@ifinfo} and
@code{@@end ifinfo} commands so that the formatters place it only
in the Info file.@refill

@item
A title page and copyright page, with a copyright notice and copying
permissions.  This is enclosed between @code{@@titlepage} and
@code{@@end titlepage} commands.  The title and copyright page appear
only in the printed @w{manual}.@refill

@item
The `Top' node that contains a menu for the whole Info file.  The
contents of this node appear only in the Info file.@refill
@end enumerate

Also, optionally, you may include the copying conditions for a program
and a warranty disclaimer.  The copying section will be followed by an
introduction or else by the first chapter of the manual.@refill

Since the copyright notice and copying permissions for the Texinfo
document (in contrast to the copying permissions for a program) are in
parts that appear only in the Info file or only in the printed manual,
this information must be given twice.@refill

@node Sample Beginning, Header, Four Parts, Beginning a File
@comment  node-name,  next,  previous,  up
@section Sample Texinfo File Beginning

The following sample shows what is needed.@refill

@example
\input texinfo   @@c -*-texinfo-*-
@@c %**start of header
@@setfilename @var{name-of-info-file}
@@settitle @var{name-of-manual}
@@setchapternewpage odd
@@c %**end of header

@@ifinfo
This file documents @dots{}

Copyright @var{year} @var{copyright-owner}

@group
Permission is granted to @dots{}
@@end ifinfo
@end group

@group
@@c  This title page illustrates only one of the
@@c  two methods of forming a title page.
@end group

@group
@@titlepage
@@title @var{name-of-manual-when-printed}
@@subtitle @var{subtitle-if-any}
@@subtitle @var{second-subtitle}
@@author @var{author}
@end group

@group
@@c  The following two commands
@@c  start the copyright page.
@@page
@@vskip 0pt plus 1filll
Copyright @@copyright@{@} @var{year} @var{copyright-owner}
@end group

Published by @dots{}

Permission is granted to @dots{}
@@end titlepage

@@node Top, Overview, (dir), (dir)

@@ifinfo
This document describes @dots{}

This document applies to version @dots{}
of the program named @dots{}
@@end ifinfo

@group
@@menu
* Copying::          Your rights and freedoms.
* First Chapter::    Getting started @dots{}
* Second Chapter::              @dots{}
  @dots{}
  @dots{}
@@end menu
@end group

@group
@@node    First Chapter, Second Chapter, top,      top
@@comment node-name,     next,           previous, up
@@chapter First Chapter
@@cindex Index entry for First Chapter
@end group
@end example

@node Header, Info Summary and Permissions, Sample Beginning, Beginning a File
@comment  node-name,  next,  previous,  up
@section The Texinfo File Header
@cindex Header for Texinfo files
@cindex Texinfo file header

Texinfo files start with at least three lines that provide Info and
@TeX{} with necessary information.  These are the @code{\input
texinfo} line, the @code{@@settitle} line, and the
@code{@@setfilename} line.  If you want to run @TeX{} on just a part
of the Texinfo File, you must write the @code{@@settitle}
and @code{@@setfilename} lines between start-of-header and end-of-header
lines.@refill

Thus, the beginning of a Texinfo file looks like this:

@example
@group
\input texinfo   @@c -*-texinfo-*-
@@setfilename sample.info
@@settitle Sample Document
@end group
@end example

@noindent
or else like this:

@example
@group
\input texinfo   @@c -*-texinfo-*-
@@c %**start of header
@@setfilename sample.info
@@settitle Sample Document
@@c %**end of header
@end group
@end example

@menu
* First Line::                  The first line of a Texinfo file.
* Start of Header::             Formatting a region requires this.
* setfilename::                 Tell Info the name of the Info file.
* settitle::                    Create a title for the printed work.
* setchapternewpage::           Start chapters on right-hand pages.
* paragraphindent::             An option to specify paragraph indentation.
* End of Header::               Formatting a region requires this.
@end menu

@node First Line, Start of Header, Header, Header
@comment  node-name,  next,  previous,  up
@subsection The First Line of a Texinfo File
@cindex First line of a Texinfo file
@cindex Beginning line of a Texinfo file
@cindex Header of a Texinfo file

Every Texinfo file that is to be the top-level input to @TeX{} must begin
with a line that looks like this:@refill

@example
\input texinfo   @@c -*-texinfo-*-
@end example

@noindent
This line serves two functions:

@enumerate
@item
When the file is processed by @TeX{}, the @code{\input texinfo} command
tells @TeX{} to load the macros needed for processing a Texinfo file.
These are in a file called @file{texinfo.tex}, which is usually located
in the @file{/usr/lib/tex/macros} directory.  @TeX{} uses the backslash,
@samp{\}, to mark the beginning of a command, just as Texinfo uses
@code{@@}.  The @file{texinfo.tex} file causes the switch from @samp{\}
to @samp{@@}; before the switch occurs, @TeX{} requires @samp{\}, which
is why it appears at the beginning of the file.@refill

@item
When the file is edited in GNU Emacs, the @samp{-*-texinfo-*-} mode
specification tells Emacs to use Texinfo mode.@refill
@end enumerate

@node Start of Header, setfilename, First Line, Header
@comment  node-name,  next,  previous,  up
@subsection Start of Header
@cindex Start of header line

Write a start-of-header line on the second line of a Texinfo file.
Follow the start-of-header line with @code{@@setfilename} and
@code{@@settitle} lines and, optionally, with other command lines, such
as @code{@@smallbook} or @code{@@footnotestyle}; and then by an
end-of-header line (@pxref{End of Header}).@refill

With these lines, you can format part of a Texinfo file for Info or
typeset part for printing.@refill

A start-of-header line looks like this:@refill

@example
@@c %**start of header
@end example

The odd string of characters, @samp{%**}, is to ensure that no other
comment is accidentally taken for a start-of-header line.@refill

@node setfilename, settitle, Start of Header, Header
@comment  node-name,  next,  previous,  up
@subsection @code{@@setfilename}
@cindex Info file requires @code{@@setfilename}
@findex setfilename

In order to serve as the primary input file for either @code{makeinfo}
or @TeX{}, a Texinfo file must contain a line that looks like this:

@example
@@setfilename @var{info-file-name}
@end example

Write the @code{@@setfilename} command at the beginning of a line and
follow it on the same line by the Info file name.  Do not write
anything else on the line; anything on the line after the command is
considered part of the file name, including a comment.@refill

The @code{@@setfilename} line specifies the name of the Info file to be
generated.  This name should be different from the name of the Texinfo
file.  There are two conventions for choosing the name: you can either
remove the @samp{.tex} extension from the input file name, or replace it
with the @samp{.info} extension.

Some operating systems cannot handle long file names.  You can run into
a problem even when the file name you specify is itself short enough.
This occurs because the Info formatters split a long Info file into
short indirect subfiles, and name them by appending `-1', `-2', @dots{},
`-10', `-11', and so on, to the original file name.  (@xref{Tag and
Split Files, , Tag Files and Split Files}.)  The subfile name
@file{texinfo.info-10}, for example, is too long for some systems; so
the Info file name for this document is @file{texinfo} rather than
@file{texinfo.info}.@refill

The Info formatting commands ignore everything written before the
@code{@@setfilename} line, which is why the very first line of
the file (the @code{\input} line) does not need to be commented out.

The @code{@@setfilename} line produces no output when you typeset a
printed manual, but is does an essential job: it opens the index,
cross-reference, and other auxiliary files used by Texinfo.

@node settitle, setchapternewpage, setfilename, Header
@comment  node-name,  next,  previous,  up
@subsection @code{@@settitle}
@findex settitle

In order to be made into a printed manual, a Texinfo file must contain
a line that looks like this:@refill

@example
@@settitle @var{title}
@end example

Write the @code{@@settitle} command at the beginning of a line and
follow it on the same line by the title.  This tells @TeX{} the title
to use in a header or footer.  Do not write anything else on the line;
anything on the line after the command is considered part of the
title, including a comment.@refill

Conventionally, when @TeX{} formats a Texinfo file for double-sided
output, the title is printed in the left-hand (even-numbered) page
headings and the current chapter title is printed in the right-hand
(odd-numbered) page headings.  (@TeX{} learns the title of each chapter
from each @code{@@chapter} command.)  Page footers are not
printed.@refill

Even if you are printing in a single-sided style, @TeX{} looks for an
@code{@@settitle} command line, in case you include the manual title
in the heading. @refill

The @code{@@settitle} command should precede everything that generates
actual output in @TeX{}.@refill

Although the title in the @code{@@settitle} command is usually the
same as the title on the title page, it does not affect the title as
it appears on the title page.  Thus, the two do not need not match
exactly;  and the title in the @code{@@settitle} command can be a
shortened or expanded version of the title as it appears on the title
page. (@xref{titlepage, , @code{@@titlepage}}.)@refill

@TeX{} prints page headings only for that text that comes after the
@code{@@end titlepage} command in the Texinfo file, or that comes
after an @code{@@headings} command that turns on headings.
(@xref{headings on off, , The @code{@@headings} Command}, for more
information.)@refill

You may, if you wish, create your own, customized headings and
footings.  @xref{Headings, , Page Headings}, for a detailed discussion
of this process.@refill

@node setchapternewpage, paragraphindent, settitle, Header
@comment  node-name,  next,  previous,  up
@subsection @code{@@setchapternewpage}
@cindex Starting chapters
@cindex Pages, starting odd
@findex setchapternewpage

In a book or a manual, text is usually printed on both sides of the
paper, chapters start on right-hand pages, and right-hand pages have
odd numbers.  But in short reports, text often is printed only on one
side of the paper.  Also in short reports, chapters sometimes do not
start on new pages, but are printed on the same page as the end of the
preceding chapter, after a small amount of vertical whitespace.@refill

You can use the @code{@@setchapternewpage} command with various
arguments to specify how @TeX{} should start chapters and whether it
should typeset pages for printing on one or both sides of the paper
(single-sided or double-sided printing).@refill

Write the @code{@@setchapternewpage} command at the beginning of a
line followed by its argument.@refill

For example, you would write the following to cause each chapter to
start on a fresh odd-numbered page:@refill

@example
@@setchapternewpage odd
@end example

You can specify one of three alternatives with the
@code{@@setchapternewpage} command:@refill

@table @asis
@ignore
@item No @code{@@setchapternewpage} command
If the Texinfo file does not contain an @code{@@setchapternewpage}
command before the @code{@@titlepage} command, @TeX{} automatically
begins chapters on new pages and prints headings in the standard
format for single-sided printing.  This is the conventional format for
single-sided printing.@refill

The result is exactly the same as when you write
@code{@@setchapternewpage on}.@refill
@end ignore
@item @code{@@setchapternewpage off}
Cause @TeX{} to typeset a new chapter on the same page as the last
chapter, after skipping some vertical whitespace.  Also, cause @TeX{} to
format page headers for single-sided printing. (You can override the
headers format with the @code{@@headings double} command; see
@ref{headings on off, , The @code{@@headings} Command}.)@refill

@item @code{@@setchapternewpage on}
Cause @TeX{} to start new chapters on new pages and to typeset page
headers for single-sided printing.  This is the form most often
used for short reports.@refill

This alternative is the default.@refill

@item @code{@@setchapternewpage odd}
Cause @TeX{} to start new chapters on new, odd-numbered pages
(right-handed pages) and to typeset for double-sided printing.  This is
the form most often used for books and manuals.@refill
@end table

@noindent
Texinfo does not have an @code{@@setchapternewpage even} command.@refill

@noindent
(You can countermand or modify an @code{@@setchapternewpage} command
with an @code{@@headings} command.  @xref{headings on off, , The
@code{@@headings} Command}.)@refill

At the beginning of a manual or book, pages are not numbered---for
example, the title and copyright pages of a book are not numbered.
By convention, table of contents pages are numbered with roman
numerals and not in sequence with the rest of the document.@refill

Since an Info file does not have pages, the @code{@@setchapternewpage}
command has no effect on it.@refill

Usually, you do not write an @code{@@setchapternewpage} command for
single-sided printing, but accept the default which is to typeset for
single-sided printing and to start new chapters on new pages.  Usually,
you write an @code{@@setchapternewpage odd} command for double-sided
printing.@refill

@node paragraphindent, End of Header, setchapternewpage, Header
@comment  node-name,  next,  previous,  up
@subsection Paragraph Indenting
@cindex Indenting paragraphs
@cindex Paragraph indentation
@findex paragraphindent

The Info formatting commands may insert spaces at the beginning of the
first line of each paragraph, thereby indenting that paragraph.  You
can use the @code{@@paragraphindent} command to specify the
indentation.  Write an @code{@@paragraphindent} command at the
beginning of a line followed by either @samp{asis} or a number.  The
template is:@refill

@example
@@paragraphindent @var{indent}
@end example

The Info formatting commands indent according to the value of
@var{indent}:@refill

@itemize @bullet
@item
If the value of @var{indent} is @samp{asis}, the Info formatting
commands do not change the existing indentation.@refill

@item
If the value of @var{indent} is 0, the Info formatting commands delete
existing indentation.@refill

@item
If the value of @var{indent} is greater than 0, the Info formatting
commands indent the paragraph by that number of spaces.@refill
@end itemize

The default value of @var{indent} is @samp{asis}.@refill

Write the @code{@@paragraphindent} command before or shortly after the
end-of-header line at the beginning of a Texinfo file.  (If you write
the command between the start-of-header and end-of-header lines, the
region formatting commands indent paragraphs as specified.)@refill

A peculiarity of the @code{texinfo-format-buffer} and
@code{texinfo-format-region} commands is that they do not indent (nor
fill) paragraphs that contain @code{@@w} or @code{@@*} commands.
@xref{Refilling Paragraphs}, for a detailed description of what goes
on.@refill

@node End of Header, , paragraphindent, Header
@comment  node-name,  next,  previous,  up
@subsection End of Header
@cindex End of header line

Follow the header lines with an @w{end-of-header} line.
An end-of-header line looks like this:@refill

@example
@@c %**end of header
@end example

If you include the @code{@@setchapternewpage} command between the
start-of-header and end-of-header lines, @TeX{} will typeset a region as
that command specifies.  Similarly, if you include an @code{@@smallbook}
command between the start-of-header and end-of-header lines, @TeX{} will
typeset a region in the ``small'' book format.@refill

@ifinfo
The reason for the odd string of characters (@samp{%**}) is so that the
@code{texinfo-tex-region} command does not accidentally find
something that it should not when it is looking for the header.@refill

The start-of-header line and the end-of-header line are Texinfo mode
variables that you can change.@refill
@end ifinfo

@iftex
@xref{Start of Header}.
@end iftex

@node Info Summary and Permissions, Titlepage & Copyright Page, Header, Beginning a File
@comment  node-name,  next,  previous,  up
@section Summary and Copying Permissions for Info

The title page and the copyright page appear only in the printed copy of
the manual; therefore, the same information must be inserted in a
section that appears only in the Info file.  This section usually
contains a brief description of the contents of the Info file, a
copyright notice, and copying permissions.@refill

The copyright notice should read:@refill

@example
Copyright @var{year} @var{copyright-owner}
@end example

@noindent
and be put on a line by itself.@refill

Standard text for the copyright permissions is contained in an appendix
to this manual; see @ref{ifinfo Permissions, , @samp{ifinfo} Copying
Permissions}, for the complete text.@refill

The permissions text appears in an Info file @emph{before} the first
node.  This mean that a reader does @emph{not} see this text when
reading the file using Info, except when using the advanced Info command
@kbd{g *}.

@node Titlepage & Copyright Page, The Top Node, Info Summary and Permissions, Beginning a File
@comment  node-name,  next,  previous,  up
@section The Title and Copyright Pages

A manual's name and author are usually printed on a title page.
Sometimes copyright information is printed on the title page as well;
more often, copyright information is printed on the back of the title
page.

The title and copyright pages appear in the printed manual, but not in the
Info file.  Because of this, it is possible to use several slightly
obscure @TeX{} typesetting commands that cannot be used in an Info file.
In addition, this part of the beginning of a Texinfo file contains the text
of the copying permissions that will appear in the printed manual.@refill

@xref{Titlepage Permissions, , Titlepage Copying Permissions}, for the
standard text for the copyright permissions.@refill

@menu
* titlepage::                   Create a title for the printed document.
* titlefont center sp::         The @code{@@titlefont}, @code{@@center},
                                  and @code{@@sp} commands.
* title subtitle author::       The @code{@@title}, @code{@@subtitle},
                                  and @code{@@author} commands.
* Copyright & Permissions::     How to write the copyright notice and
                                  include copying permissions.
* end titlepage::               Turn on page headings after the title and
                                  copyright pages.
* headings on off::             An option for turning headings on and off
                                  and double or single sided printing.
@end menu

@node titlepage, titlefont center sp, Titlepage & Copyright Page, Titlepage & Copyright Page
@comment  node-name,  next,  previous,  up
@subsection @code{@@titlepage}
@cindex Title page
@findex titlepage

Start the material for the title page and following copyright page
with @code{@@titlepage} on a line by itself and end it with
@code{@@end titlepage} on a line by itself.@refill

The @code{@@end titlepage} command starts a new page and turns on page
numbering.  (@xref{Headings, , Page Headings}, for details about how to
generate page headings.)  All the material that you want to
appear on unnumbered pages should be put between the
@code{@@titlepage} and @code{@@end titlepage} commands.  By using the
@code{@@page} command you can force a page break within the region
delineated by the @code{@@titlepage} and @code{@@end titlepage}
commands and thereby create more than one unnumbered page.  This is
how the copyright page is produced.  (The @code{@@titlepage} command
might perhaps have been better named the
@code{@@titleandadditionalpages} command, but that would have been
rather long!)@refill

@c !!! append refill to footnote when makeinfo can handle it.
When you write a manual about a computer program, you should write the
version of the program to which the manual applies on the title
page.  If the manual changes more frequently than the program or is
independent of it, you should also include an edition
number@footnote{We have found that it is helpful to refer to versions
of manuals as `editions' and versions of programs as `versions';
otherwise, we find we are liable to confuse each other in conversation
by referring to both the documentation and the software with the same
words.} for the manual.  This helps readers keep track of which manual
is for which version of the program.  (The `Top' node
should also contain this information; see @ref{makeinfo top, ,
@code{@@top}}.)@refill

Texinfo provides two main methods for creating a title page.  One method
uses the @code{@@titlefont}, @code{@@sp}, and @code{@@center} commands
to generate a title page in which the words on the page are
centered.@refill

The second method uses the @code{@@title}, @code{@@subtitle}, and
@code{@@author} commands to create a title page with black rules under
the title and author lines and the subtitle text set flush to the
right hand side of the page.  With this method, you do not specify any
of the actual formatting of the title page.  You specify the text
you want, and Texinfo does the formatting.  You may use either
method.@refill

@findex shorttitlepage
For extremely simple applications, Texinfo also provides a command
@code{@@shorttitlepage} which takes a single argument as the title.
The argument is typeset on a page by itself and followed by a blank
page.


@node titlefont center sp, title subtitle author, titlepage, Titlepage & Copyright Page
@comment  node-name,  next,  previous,  up
@subsection @code{@@titlefont}, @code{@@center}, and @code{@@sp}
@findex titlefont
@findex center
@findex sp @r{(titlepage line spacing)}

You can use the @code{@@titlefont}, @code{@@sp}, and @code{@@center}
commands to create a title page for a printed document.  (This is the
first of the two methods for creating a title page in Texinfo.)@refill

Use the @code{@@titlefont} command to select a large font suitable for
the title itself.@refill

@need 700
For example:

@example
@@titlefont@{Texinfo@}
@end example

Use the @code{@@center} command at the beginning of a line to center
the remaining text on that line.  Thus,@refill

@example
@@center @@titlefont@{Texinfo@}
@end example

@noindent
centers the title, which in this example is ``Texinfo'' printed
in the title font.@refill

Use the @code{@@sp} command to insert vertical space.  For example:@refill

@example
@@sp 2
@end example

@noindent
This inserts two blank lines on the printed page.  (@xref{sp, ,
@code{@@sp}}, for more information about the @code{@@sp}
command.)@refill

A template for this method looks like this:@refill

@example
@group
@@titlepage
@@sp 10
@@center @@titlefont@{@var{name-of-manual-when-printed}@}
@@sp 2
@@center @var{subtitle-if-any}
@@sp 2
@@center @var{author}
@dots{}
@@end titlepage
@end group
@end example

The spacing of the example fits an 8 1/2 by 11 inch manual.@refill

@node title subtitle author, Copyright & Permissions, titlefont center sp, Titlepage & Copyright Page
@comment  node-name,  next,  previous,  up
@subsection @code{@@title}, @code{@@subtitle}, and @code{@@author}
@findex title
@findex subtitle
@findex author

You can use the @code{@@title}, @code{@@subtitle}, and @code{@@author}
commands to create a title page in which the vertical and horizontal
spacing is done for you automatically.  This contrasts with the method
described in
the previous section, in which the @code{@@sp} command is needed to
adjust vertical spacing.@refill

Write the @code{@@title}, @code{@@subtitle}, or @code{@@author}
commands at the beginning of a line followed by the title, subtitle,
or author.@refill

The @code{@@title} command produces a line in which the title is set
flush to the left-hand side of the page in a larger than normal font.
The title is underlined with a black rule.@refill

The @code{@@subtitle} command sets subtitles in a normal-sized font
flush to the right-hand side of the page.@refill

The @code{@@author} command sets the names of the author or authors in
a middle-sized font flush to the left-hand side of the page on a line
near the bottom of the title page.  The names are underlined with a
black rule that is thinner than the rule that underlines the title.
(The black rule only occurs if the @code{@@author} command line is
followed by an @code{@@page} command line.)@refill

There are two ways to use the @code{@@author} command: you can write
the name or names on the remaining part of the line that starts with
an @code{@@author} command:@refill

@example
@@author by Jane Smith and John Doe
@end example

@noindent
or you can write the names one above each other by using two (or more)
@code{@@author} commands:@refill

@example
@group
@@author Jane Smith
@@author John Doe
@end group
@end example

@noindent
(Only the bottom name is underlined with a black rule.)@refill

@need 950
A template for this method looks like this:@refill

@example
@group
@@titlepage
@@title @var{name-of-manual-when-printed}
@@subtitle @var{subtitle-if-any}
@@subtitle @var{second-subtitle}
@@author @var{author}
@@page
@dots{}
@@end titlepage
@end group
@end example

@ifinfo
@noindent
Contrast this form with the form of a title page written using the
@code{@@sp}, @code{@@center}, and @code{@@titlefont} commands:@refill

@example
@@titlepage
@@sp 10
@@center @@titlefont@{Name of Manual When Printed@}
@@sp 2
@@center Subtitle, If Any
@@sp 1
@@center Second subtitle
@@sp 2
@@center Author
@@page
@dots{}
@@end titlepage
@end example
@end ifinfo

@node Copyright & Permissions, end titlepage, title subtitle author, Titlepage & Copyright Page
@comment  node-name,  next,  previous,  up
@subsection Copyright Page and Permissions
@cindex Copyright page
@cindex Printed permissions
@cindex Permissions, printed

By international treaty, the copyright notice for a book should be
either on the title page or on the back of the title page.  The
copyright notice should include the year followed by the name of the
organization or person who owns the copyright.@refill

When the copyright notice is on the back of the title page, that page
is customarily not numbered.  Therefore, in Texinfo, the information
on the copyright page should be within @code{@@titlepage} and
@code{@@end titlepage} commands.@refill

@findex vskip
@findex filll
@cindex Vertical whitespace (@samp{vskip})
Use the @code{@@page} command to cause a page break.  To push the
copyright notice and the other text on the copyright page towards the
bottom of the page, you can write a somewhat mysterious line after the
@code{@@page} command that reads like this:@refill

@example
@@vskip 0pt plus 1filll
@end example

@noindent
This is a @TeX{} command that is not supported by the Info formatting
commands.  The @code{@@vskip} command inserts whitespace.  The
@samp{0pt plus 1filll} means to put in zero points of mandatory whitespace,
and as much optional whitespace as needed to push the
following text to the bottom of the page.  Note the use of three
@samp{l}s in the word @samp{filll}; this is the correct usage in
@TeX{}.@refill

@findex copyright
In a printed manual, the @code{@@copyright@{@}} command generates a
@samp{c} inside a circle.  (In Info, it generates @samp{(C)}.)  The
copyright notice itself has the following legally defined sequence:@refill

@example
Copyright @copyright{} @var{year} @var{copyright-owner}
@end example

It is customary to put information on how to get a manual after the
copyright notice, followed by the copying permissions for the
manual.@refill

Note that permissions must be given here as well as in the summary
segment within @code{@@ifinfo} and @code{@@end ifinfo} that
immediately follows the header since this text appears only in the
printed manual and the @samp{ifinfo} text appears only in the Info
file.@refill

@xref{Sample Permissions}, for the standard text.@refill

@node end titlepage, headings on off, Copyright & Permissions, Titlepage & Copyright Page
@comment  node-name,  next,  previous,  up
@subsection Heading Generation
@findex end titlepage
@cindex Headings, page, begin to appear
@cindex Titlepage end starts headings
@cindex End titlepage starts headings

An @code{@@end titlepage} command on a line by itself not only marks
the end of the title and copyright pages, but also causes @TeX{} to start
generating page headings and page numbers.

To repeat what is said elsewhere,  Texinfo has two standard page heading
formats, one for documents which are printed on one side of each sheet of paper
(single-sided printing), and the other for documents which are printed on both
sides of each sheet (double-sided printing).
(@xref{setchapternewpage, ,@code{@@setchapternewpage}}.)
You can specify these formats in different ways:@refill

@itemize @bullet
@item
The conventional way is to write an @code{@@setchapternewpage} command
before the title page commands, and then have the @code{@@end
titlepage} command start generating page headings in the manner desired.
(@xref{setchapternewpage, , @code{@@setchapternewpage}}.)@refill

@item
Alternatively, you can use the @code{@@headings} command to prevent page
headings from being generated or to start them for either single or
double-sided printing.  (Write an @code{@@headings} command immediately
after the @code{@@end titlepage} command.  @xref{headings on off, , The
@code{@@headings} Command}, for more information.)@refill

@item
Or, you may specify your own page heading and footing format.
@xref{Headings, , Page Headings}, for detailed
information about page headings and footings.@refill
@end itemize

Most documents are formatted with the standard single-sided or
double-sided format, using @code{@@setchapternewpage odd} for
double-sided printing and no @code{@@setchapternewpage} command for
single-sided printing.@refill

@node headings on off, , end titlepage, Titlepage & Copyright Page
@comment  node-name,  next,  previous,  up
@subsection The @code{@@headings} Command
@findex headings

The @code{@@headings} command is rarely used.  It specifies what kind of
page headings and footings to print on each page.  Usually, this is
controlled by the @code{@@setchapternewpage} command.  You need the
@code{@@headings} command only if the @code{@@setchapternewpage} command
does not do what you want, or if you want to turn off pre-defined page
headings prior to defining your own.  Write an @code{@@headings} command
immediately after the @code{@@end titlepage} command.@refill

You can use @code{@@headings} as follows:@refill

@table @code
@item @@headings off
Turn off printing of page headings.@refill

@item @@headings single
Turn on page headings appropriate for single-sided printing.
@refill

@item @@headings double
Turn on page headings appropriate for double-sided printing.  The two
commands, @code{@@headings on} and @code{@@headings double}, are
synonymous.@refill

@item @@headings singleafter
@itemx @@headings doubleafter
Turn on @code{single} or @code{double} headings, respectively, after the
current page is output.

@item @@headings on
Turn on page headings: @code{single} if @samp{@@setchapternewpage
on}, @code{double} otherwise.
@end table

For example, suppose you write @code{@@setchapternewpage off} before the
@code{@@titlepage} command to tell @TeX{} to start a new chapter on the
same page as the end of the last chapter.  This command also causes
@TeX{} to typeset page headers for single-sided printing.  To cause
@TeX{} to typeset for double sided printing, write @code{@@headings
double} after the @code{@@end titlepage} command.

You can stop @TeX{} from generating any page headings at all by
writing @code{@@headings off} on a line of its own immediately after the
line containing the @code{@@end titlepage} command, like this:@refill

@example
@@end titlepage
@@headings off
@end example

@noindent
The @code{@@headings off} command overrides the @code{@@end titlepage}
command, which would otherwise cause @TeX{} to print page
headings.@refill

You can also specify your own style of page heading and footing.
@xref{Headings, , Page Headings}, for more information.@refill

@node The Top Node, Software Copying Permissions, Titlepage & Copyright Page, Beginning a File
@comment  node-name,  next,  previous,  up
@section The `Top' Node and Master Menu
@cindex @samp{@r{Top}} node
@cindex Master menu
@cindex Node, `Top'

The `Top' node is the node from which you enter an Info file.@refill

A `Top' node should contain a brief description of the Info file and an
extensive, master menu for the whole Info file.
This helps the reader understand what the Info file is
about.  Also, you should write the version number of the program to
which the Info file applies; or, at least, the edition number.@refill

The contents of the `Top' node should appear only in the Info file; none
of it should appear in printed output, so enclose it between
@code{@@ifinfo} and @code{@@end ifinfo} commands.  (@TeX{} does not
print either an @code{@@node} line or a menu; they appear only in Info;
strictly speaking, you are not required to enclose these parts between
@code{@@ifinfo} and @code{@@end ifinfo}, but it is simplest to do so.
@xref{Conditionals, , Conditionally Visible Text}.)@refill

@menu
* Title of Top Node::           Sketch what the file is about.
* Master Menu Parts::           A master menu has three or more parts.
@end menu

@node Title of Top Node, Master Menu Parts, The Top Node, The Top Node
@ifinfo
@subheading `Top' Node Title
@end ifinfo

Sometimes, you will want to place an @code{@@top} sectioning command
line containing the title of the document immediately after the
@code{@@node Top} line (@pxref{makeinfo top command, , The @code{@@top}
Sectioning Command}, for more information).@refill

For example, the beginning of the Top node of this manual contains an
@code{@@top} sectioning command, a short description, and edition and
version information.  It looks like this:@refill

@example
@group
@dots{}
@@end titlepage

@@ifinfo
@@node Top, Copying, (dir), (dir)
@@top Texinfo

Texinfo is a documentation system@dots{}
@end group

@group
This is edition@dots{}
@dots{}
@@end ifinfo
@end group

@group
@@menu
* Copying::                 Texinfo is freely
                              redistributable.
* Overview::                What is Texinfo?
@dots{}
@end group
@@end menu
@end example

In a `Top' node, the `Previous', and `Up' nodes usually refer to the top
level directory of the whole Info system, which is called @samp{(dir)}.
The `Next' node refers to the first node that follows the main or master
menu, which is usually the copying permissions, introduction, or first
chapter.@refill

@node Master Menu Parts, , Title of Top Node, The Top Node
@subsection Parts of a Master Menu
@cindex Master menu parts
@cindex Parts of a master menu

A @dfn{master menu} is a detailed main menu listing all the nodes in a
file.

A master menu is enclosed in @code{@@menu} and @code{@@end menu}
commands and does not appear in the printed document.@refill

Generally, a master menu is divided into parts.@refill

@itemize @bullet
@item
The first part contains the major nodes in the Texinfo file: the nodes
for the chapters, chapter-like sections, and the appendices.@refill

@item
The second part contains nodes for the indices.@refill

@item
The third and subsequent parts contain a listing of the other, lower
level nodes, often ordered by chapter.  This way, rather than go
through an intermediary menu, an inquirer can go directly to a
particular node when searching for specific information.  These menu
items are not required; add them if you think they are a
convenience.  If you do use them, put @code{@@detailmenu} before the
first one, and @code{@@end detailmenu} after the last; otherwise,
@code{makeinfo} will get confused.
@end itemize

Each section in the menu can be introduced by a descriptive line.  So
long as the line does not begin with an asterisk, it will not be
treated as a menu entry.  (@xref{Writing a Menu}, for more
information.)@refill

For example, the master menu for this manual looks like the following
(but has many more entries):@refill

@example
@group
@@menu
* Copying::             Texinfo is freely
                          redistributable.
* Overview::            What is Texinfo?
* Texinfo Mode::        Special features in GNU Emacs.
@dots{}
@dots{}
@end group
@group
* Command and Variable Index::
                        An entry for each @@-command.
* Concept Index::       An entry for each concept.
@end group

@group
@@detailmenu
 --- The Detailed Node Listing ---

Overview of Texinfo

* Info Files::          What is an Info file?
* Printed Manuals::     Characteristics of
                          a printed manual.
@dots{}
@dots{}
@end group

@group
Using Texinfo Mode

* Info on a Region::    Formatting part of a file
                          for Info.
@dots{}
@dots{}
@@end detailmenu
@@end menu
@end group
@end example

@node Software Copying Permissions, , The Top Node, Beginning a File
@comment  node-name,  next,  previous,  up
@section Software Copying Permissions
@cindex Software copying permissions
@cindex Copying software
@cindex Distribution
@cindex License agreement

If the Texinfo file has a section containing the ``General Public
License'' and the distribution information and a warranty disclaimer
for the software that is documented, this section usually follows the
`Top' node.  The General Public License is very important to Project
GNU software.  It ensures that you and others will continue to have a
right to use and share the software.@refill

The copying and distribution information and the disclaimer are
followed by an introduction or else by the first chapter of the
manual.@refill

@cindex Introduction, as part of file
Although an introduction is not a required part of a Texinfo file, it
is very helpful.  Ideally, it should state clearly and concisely what
the file is about and who would be interested in reading it.  In
general, an introduction would follow the licensing and distribution
information, although sometimes people put it earlier in the document.
Usually, an introduction is put in an @code{@@unnumbered} section.
(@xref{unnumbered & appendix, , The @code{@@unnumbered} and
@code{@@appendix} Commands}.)@refill

@node Ending a File, Structuring, Beginning a File, Top
@comment  node-name,  next,  previous,  up
@chapter Ending a Texinfo File
@cindex Ending a Texinfo file
@cindex Texinfo file ending
@cindex File ending
@findex bye

The end of a Texinfo file should include the commands that create
indices and generate detailed and summary tables of contents.
And it must include the @code{@@bye} command that marks the last line
processed by @TeX{}.@refill

@need 700
For example:

@example
@@node    Concept Index,     , Variables Index, Top
@@c        node-name,    next, previous,        up
@@unnumbered Concept Index

@@printindex cp

@@contents
@@bye
@end example

@menu
* Printing Indices & Menus::    How to print an index in hardcopy and
                                  generate index menus in Info.
* Contents::                    How to create a table of contents.
* File End::                    How to mark the end of a file.
@end menu

@node Printing Indices & Menus, Contents, Ending a File, Ending a File
@comment  node-name,  next,  previous,  up
@section Index Menus and Printing an Index
@findex printindex
@cindex Printing an index
@cindex Indices, printing and menus
@cindex Generating menus with indices
@cindex Menus generated with indices

To print an index means to include it as part of a manual or Info
file.  This does not happen automatically just because you use
@code{@@cindex} or other index-entry generating commands in the
Texinfo file; those just cause the raw data for the index to be
accumulated.  To generate an index, you must include the
@code{@@printindex} command at the place in the document where you
want the index to appear.  Also, as part of the process of creating a
printed manual, you must run a program called @code{texindex}
(@pxref{Format/Print Hardcopy}) to sort the raw data to produce a sorted
index file.  The sorted index file is what is actually used to
print the index.@refill

Texinfo offers six different types of predefined index: the concept
index, the function index, the variables index, the keystroke index, the
program index, and the data type index (@pxref{Predefined Indices}).  Each
index type has a two-letter name: @samp{cp}, @samp{fn}, @samp{vr},
@samp{ky}, @samp{pg}, and @samp{tp}.  You may merge indices, or put them
into separate sections (@pxref{Combining Indices}); or you may define
your own indices (@pxref{New Indices, , Defining New Indices}).@refill

The @code{@@printindex} command takes a two-letter index name, reads
the corresponding sorted index file and formats it appropriately into
an index.@refill

@ignore
The two-letter index names are:

@table @samp
@item cp
concept index
@item fn
function index
@item vr
variable index
@item ky
key index
@item pg
program index
@item tp
data type index
@end table
@end ignore
The @code{@@printindex} command does not generate a chapter heading
for the index.  Consequently, you should precede the
@code{@@printindex} command with a suitable section or chapter command
(usually @code{@@unnumbered}) to supply the chapter heading and put
the index into the table of contents.  Precede the @code{@@unnumbered}
command with an @code{@@node} line.@refill

@need 1200
For example:

@smallexample
@group
@@node Variable Index, Concept Index, Function Index, Top
@@comment    node-name,         next,       previous, up
@@unnumbered Variable Index

@@printindex vr
@end group

@group
@@node     Concept Index,     , Variable Index, Top
@@comment      node-name, next,       previous, up
@@unnumbered Concept Index

@@printindex cp
@end group

@group
@@summarycontents
@@contents
@@bye
@end group
@end smallexample

@noindent
(Readers often prefer that the concept index come last in a book,
since that makes it easiest to find.)@refill

@ignore
In @TeX{}, the @code{@@printindex} command needs a sorted index file
to work from.  @TeX{} does not know how to do sorting; this is a
deficiency.  @TeX{} writes output files of raw index data; use the
@code{texindex} program to convert these files to sorted index files.
(@xref{Format/Print Hardcopy}, for more information.)@refill
@end ignore
@node Contents, File End, Printing Indices & Menus, Ending a File
@comment  node-name,  next,  previous,  up
@section Generating a Table of Contents
@cindex Table of contents
@cindex Contents, Table of
@findex contents
@findex summarycontents
@findex shortcontents

The @code{@@chapter}, @code{@@section}, and other structuring commands
supply the information to make up a table of contents, but they do not
cause an actual table to appear in the manual.  To do this, you must
use the @code{@@contents} and @code{@@summarycontents}
commands:@refill

@table @code
@item @@contents
Generate a table of contents in a printed manual, including all
chapters, sections, subsections, etc., as well as appendices and
unnumbered chapters.  (Headings generated by the @code{@@heading}
series of commands do not appear in the table of contents.)  The
@code{@@contents} command should be written on a line by
itself.@refill

@item @@shortcontents
@itemx @@summarycontents
(@code{@@summarycontents} is a synonym for @code{@@shortcontents}; the
two commands are exactly the same.)@refill

Generate a short or summary table of contents that lists only the
chapters (and appendices and unnumbered chapters).  Omit sections, subsections
and subsubsections.  Only a long manual needs a short table
of contents in addition to the full table of contents.@refill

Write the @code{@@shortcontents} command on a line by itself right
@emph{before} the @code{@@contents} command.@refill
@end table

The table of contents commands automatically generate a chapter-like
heading at the top of the first table of contents page.  Write the table
of contents commands at the very end of a Texinfo file, just before the
@code{@@bye} command, following any index sections---anything in the
Texinfo file after the table of contents commands will be omitted from
the table of contents.@refill

When you print a manual with a table of contents, the table of
contents are printed last and numbered with roman numerals.  You need
to place those pages in their proper place, after the title page,
yourself.  (This is the only collating you need to do for a printed
manual.  The table of contents is printed last because it is generated
after the rest of the manual is typeset.)@refill

@need 700
Here is an example of where to write table of contents commands:@refill

@example
@group
@var{indices}@dots{}
@@shortcontents
@@contents
@@bye
@end group
@end example

Since an Info file uses menus instead of tables of contents, the Info
formatting commands ignore the @code{@@contents} and
@code{@@shortcontents} commands.@refill

@node File End, , Contents, Ending a File
@comment  node-name,  next,  previous,  up
@section @code{@@bye} File Ending
@findex bye

An @code{@@bye} command terminates @TeX{} or Info formatting.  None of
the formatting commands see any of the file following @code{@@bye}.
The @code{@@bye} command should be on a line by itself.@refill

If you wish, you may follow the @code{@@bye} line with notes. These notes
will not be formatted and will not appear in either Info or a printed
manual; it is as if text after @code{@@bye} were within @code{@@ignore}
@dots{} @code{@@end ignore}.  Also, you may follow the @code{@@bye} line
with a local variables list.  @xref{Compile-Command, , Using Local
Variables and the Compile Command}, for more information.@refill

@node Structuring, Nodes, Ending a File, Top
@comment  node-name,  next,  previous,  up
@chapter Chapter Structuring
@cindex Chapter structuring
@cindex Structuring of chapters

The @dfn{chapter structuring} commands divide a document into a hierarchy of
chapters, sections, subsections, and subsubsections.  These commands
generate large headings; they also provide information for the table
of contents of a printed manual (@pxref{Contents, , Generating a Table
of Contents}).@refill

The chapter structuring commands do not create an Info node structure,
so normally you should put an @code{@@node} command immediately before
each chapter structuring command (@pxref{Nodes}).  The only time you
are likely to use the chapter structuring commands without using the
node structuring commands is if you are writing a document that
contains no cross references and will never be transformed into Info
format.@refill

It is unlikely that you will ever write a Texinfo file that is
intended only as an Info file and not as a printable document.  If you
do, you might still use chapter structuring commands to create a
heading at the top of each node---but you don't need to.@refill

@menu
* Tree Structuring::            A manual is like an upside down tree @dots{}
* Structuring Command Types::   How to divide a manual into parts.
* makeinfo top::                The @code{@@top} command, part of the `Top' node.
* chapter::                     
* unnumbered & appendix::       
* majorheading & chapheading::  
* section::                     
* unnumberedsec appendixsec heading::  
* subsection::                  
* unnumberedsubsec appendixsubsec subheading::  
* subsubsection::               Commands for the lowest level sections.
* Raise/lower sections::        How to change commands' hierarchical level.
@end menu

@node Tree Structuring, Structuring Command Types, Structuring, Structuring
@comment  node-name,  next,  previous,  up
@section Tree Structure of Sections
@cindex Tree structuring

A Texinfo file is usually structured like a book with chapters,
sections, subsections, and the like.  This structure can be visualized
as a tree (or rather as an upside-down tree) with the root at the top
and the levels corresponding to chapters, sections, subsection, and
subsubsections.@refill

Here is a diagram that shows a Texinfo file with three chapters,
each of which has two sections.@refill

@example
@group
                          Top
                           |
         -------------------------------------
        |                  |                  |
     Chapter 1          Chapter 2          Chapter 3
        |                  |                  |
     --------           --------           --------
    |        |         |        |         |        |
 Section  Section   Section  Section   Section  Section
   1.1      1.2       2.1      2.2       3.1      3.2

@end group
@end example

In a Texinfo file that has this structure, the beginning of Chapter 2
looks like this:@refill

@example
@group
@@node    Chapter 2,  Chapter 3, Chapter 1, top
@@chapter Chapter 2
@end group
@end example

The chapter structuring commands are described in the sections that
follow; the @code{@@node} and @code{@@menu} commands are described in
following chapters. (@xref{Nodes}, and see @ref{Menus}.)@refill

@node Structuring Command Types, makeinfo top, Tree Structuring, Structuring
@comment  node-name,  next,  previous,  up
@section Types of Structuring Command

The chapter structuring commands fall into four groups or series, each
of which contains structuring commands corresponding to the
hierarchical levels of chapters, sections, subsections, and
subsubsections.@refill

The four groups are the @code{@@chapter} series, the
@code{@@unnumbered} series, the @code{@@appendix} series, and the
@code{@@heading} series.@refill

Each command produces titles that have a different appearance on the
printed page or Info file; only some of the commands produce
titles that are listed in the table of contents of a printed book or
manual.@refill

@itemize @bullet
@item
The @code{@@chapter} and @code{@@appendix} series of commands produce
numbered or lettered entries both in the body of a printed work and in
its table of contents.@refill

@item
The @code{@@unnumbered} series of commands produce unnumbered entries
both in the body of a printed work and in its table of contents.  The
@code{@@top} command, which has a special use, is a member of this
series (@pxref{makeinfo top, , @code{@@top}}).@refill

@item
The @code{@@heading} series of commands produce unnumbered headings
that do not appear in a table of contents.  The heading commands never
start a new page.@refill

@item
The @code{@@majorheading} command produces results similar to using
the @code{@@chapheading} command but generates a larger vertical
whitespace before the heading.@refill

@item
When an @code{@@setchapternewpage} command says to do so, the
@code{@@chapter}, @code{@@unnumbered}, and @code{@@appendix} commands
start new pages in the printed manual; the @code{@@heading} commands
do not.@refill
@end itemize

@need 1000
Here are the four groups of chapter structuring commands:@refill

@c Slightly different formatting for regular sized books and smallbooks.
@ifset smallbook
@sp 1
@tex
{\let\rm=\indrm \let\tt=\indtt
\halign{\hskip\itemindent#\hfil&  \hskip.5em#\hfil&  \hskip.5em#\hfil&
\hskip.5em#\hfil\cr

& & &                                                \rm No new pages\cr
\rm Numbered&    \rm Unnumbered&  \rm Lettered and numbered& \rm Unnumbered\cr
\rm In contents&  \rm In contents&  \rm In contents&  \rm Not in contents\cr

& & & \cr
 &              \tt  @@top&            &               \tt @@majorheading\cr
\tt @@chapter& \tt @@unnumbered&    \tt @@appendix&     \tt @@chapheading\cr
\tt @@section&   \tt @@unnumberedsec&   \tt @@appendixsec&   \tt @@heading\cr
\tt @@subsection&\tt @@unnumberedsubsec&\tt @@appendixsubsec&
\tt @@subheading\cr
\tt @@subsubsection& \tt @@unnumberedsubsubsec& \tt @@appendixsubsubsec&
\tt @@subsubheading\cr}}
@end tex
@end ifset
@ifclear smallbook
@sp 1
@tex
\vbox{
\halign{\hskip\itemindent\hskip.5em#\hfil&  \hskip.5em#\hfil&
\hskip.5em#\hfil& \hskip.5em #\hfil\cr

& & & \cr
& & &                                                \rm No new pages\cr
\rm Numbered&    \rm Unnumbered&  \rm Lettered and numbered& \rm Unnumbered\cr
\rm In contents&  \rm In contents&  \rm In contents&  \rm Not in contents\cr

& & & \cr
 &              \tt  @@top&            &               \tt @@majorheading\cr
\tt @@chapter& \tt @@unnumbered&    \tt @@appendix&     \tt @@chapheading\cr
\tt @@section&   \tt @@unnumberedsec&   \tt @@appendixsec&   \tt @@heading\cr
\tt @@subsection&\tt @@unnumberedsubsec&\tt @@appendixsubsec&
\tt @@subheading\cr
\tt @@subsubsection& \tt @@unnumberedsubsubsec& \tt @@appendixsubsubsec&
\tt @@subsubheading\cr}}
@end tex
@end ifclear
@ifinfo
@example
@group
                                                       @r{No new pages}
@r{Numbered}       @r{Unnumbered}       @r{Lettered and numbered}  @r{Unnumbered}
@r{In contents}    @r{In contents}          @r{In contents}        @r{Not in contents}

               @@top                                    @@majorheading
@@chapter       @@unnumbered          @@appendix          @@chapheading
@@section       @@unnumberedsec       @@appendixsec       @@heading
@@subsection    @@unnumberedsubsec    @@appendixsubsec    @@subheading
@@subsubsection @@unnumberedsubsubsec @@appendixsubsubsec @@subsubheading
@end group
@end example
@end ifinfo

@c Cannot line up columns properly inside of an example because of roman
@c proportional fonts.
@ignore
@ifset smallbook
@iftex
@smallexample
@group
                                                       @r{No new pages}
@r{Numbered}      @r{Unnumbered}       @r{Lettered and numbered}  @r{Unnumbered}
@r{In contents}      @r{In contents}           @r{In contents}         @r{Not in contents}

               @@top                                    @@majorheading
@@chapter       @@unnumbered          @@appendix          @@chapheading
@@section       @@unnumberedsec       @@appendixsec       @@heading
@@subsection    @@unnumberedsubsec    @@appendixsubsec    @@subheading
@@subsubsection @@unnumberedsubsubsec @@appendixsubsubsec @@subsubheading
@end group
@end smallexample
@end iftex
@end ifset
@ifclear smallbook
@iftex
@smallexample
@group
                                                      @r{No new pages}
@r{Numbered}      @r{Unnumbered}       @r{Lettered and numbered}  @r{Unnumbered}
@r{In contents}      @r{In contents}           @r{In contents}         @r{Not in contents}

               @@top                                    @@majorheading
@@chapter       @@unnumbered          @@appendix          @@chapheading
@@section       @@unnumberedsec       @@appendixsec       @@heading
@@subsection    @@unnumberedsubsec    @@appendixsubsec    @@subheading
@@subsubsection @@unnumberedsubsubsec @@appendixsubsubsec @@subsubheading
@end group
@end smallexample
@end iftex
@end ignore

@node makeinfo top, chapter, Structuring Command Types, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@top}

The @code{@@top} command is a special sectioning command that you use
only after an @code{@@node Top} line at the beginning of a Texinfo file.
The @code{@@top} command tells the @code{makeinfo} formatter
which node is the `Top'
node.  It has the same typesetting effect as @code{@@unnumbered}
(@pxref{unnumbered & appendix, , @code{@@unnumbered}, @code{@@appendix}}).
For detailed information, see
@ref{makeinfo top command, , The @code{@@top} Command}.@refill

@node chapter, unnumbered & appendix, makeinfo top, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@chapter}
@findex chapter

@code{@@chapter} identifies a chapter in the document.  Write the
command at the beginning of a line and follow it on the same line by
the title of the chapter.@refill

For example, this chapter in this manual is entitled ``Chapter
Structuring''; the @code{@@chapter} line looks like this:@refill

@example
@@chapter Chapter Structuring
@end example

In @TeX{}, the @code{@@chapter} command creates a chapter in the
document, specifying the chapter title.  The chapter is numbered
automatically.@refill

In Info, the @code{@@chapter} command causes the title to appear on a
line by itself, with a line of asterisks inserted underneath.  Thus,
in Info, the above example produces the following output:@refill

@example
Chapter Structuring
*******************
@end example

@findex centerchap
Texinfo also provides a command @code{@@centerchap}, which is analogous
to @code{@@unnumbered}, but centers its argument in the printed output.
This kind of stylistic choice is not usually offered by Texinfo.
@c but the Hacker's Dictionary wanted it ...


@node unnumbered & appendix, majorheading & chapheading, chapter, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@unnumbered}, @code{@@appendix}
@findex unnumbered
@findex appendix

Use the @code{@@unnumbered} command to create a chapter that appears
in a printed manual without chapter numbers of any kind.  Use the
@code{@@appendix} command to create an appendix in a printed manual
that is labelled by letter instead of by number.@refill

For Info file output, the @code{@@unnumbered} and @code{@@appendix}
commands are equivalent to @code{@@chapter}: the title is printed on a
line by itself with a line of asterisks underneath.  (@xref{chapter, ,
@code{@@chapter}}.)@refill

To create an appendix or an unnumbered chapter, write an
@code{@@appendix} or @code{@@unnumbered} command at the beginning of a
line and follow it on the same line by the title, as you would if you
were creating a chapter.@refill


@node majorheading & chapheading, section, unnumbered & appendix, Structuring
@section @code{@@majorheading}, @code{@@chapheading}
@findex majorheading
@findex chapheading

The @code{@@majorheading} and @code{@@chapheading} commands put
chapter-like headings in the body of a document.@refill

However, neither command causes @TeX{} to produce a numbered heading
or an entry in the table of contents; and neither command causes
@TeX{} to start a new page in a printed manual.@refill

In @TeX{}, an @code{@@majorheading} command generates a larger vertical
whitespace before the heading than an @code{@@chapheading} command but
is otherwise the same.@refill

In Info,
the @code{@@majorheading} and
@code{@@chapheading} commands are equivalent to
@code{@@chapter}: the title is printed on a line by itself with a line
of asterisks underneath.  (@xref{chapter, , @code{@@chapter}}.)@refill

@node section, unnumberedsec appendixsec heading, majorheading & chapheading, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@section}
@findex section

In a printed manual, an @code{@@section} command identifies a
numbered section within a chapter.  The section title appears in the
table of contents.  In Info, an @code{@@section} command provides a
title for a segment of text, underlined with @samp{=}.@refill

This section is headed with an @code{@@section} command and looks like
this in the Texinfo file:@refill

@example
@@section @@code@{@@@@section@}
@end example

To create a section, write the @code{@@section} command at the
beginning of a line and follow it on the same line by the section
title.@refill

Thus,

@example
@@section This is a section
@end example

@noindent
produces

@example
@group
This is a section
=================
@end group
@end example

@noindent
in Info.

@node unnumberedsec appendixsec heading, subsection, section, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@unnumberedsec}, @code{@@appendixsec}, @code{@@heading}
@findex unnumberedsec
@findex appendixsec
@findex heading

The @code{@@unnumberedsec}, @code{@@appendixsec}, and @code{@@heading}
commands are, respectively, the unnumbered, appendix-like, and
heading-like equivalents of the @code{@@section} command.
(@xref{section, , @code{@@section}}.)@refill

@table @code
@item @@unnumberedsec
The @code{@@unnumberedsec} command may be used within an
unnumbered chapter or within a regular chapter or appendix to
provide an unnumbered section.@refill

@item @@appendixsec
@itemx @@appendixsection
@code{@@appendixsection} is a longer spelling of the
@code{@@appendixsec} command; the two are synonymous.@refill
@findex appendixsection

Conventionally, the @code{@@appendixsec} or @code{@@appendixsection}
command is used only within appendices.@refill

@item @@heading
You may use the @code{@@heading} command anywhere you wish for a
section-style heading that will not appear in the table of contents.@refill
@end table

@node subsection, unnumberedsubsec appendixsubsec subheading, unnumberedsec appendixsec heading, Structuring
@comment  node-name,  next,  previous,  up
@section The @code{@@subsection} Command
@findex subsection

Subsections are to sections as sections are to chapters.
(@xref{section, , @code{@@section}}.)  In Info, subsection titles are
underlined with @samp{-}.  For example,@refill

@example
@@subsection This is a subsection
@end example

@noindent
produces

@example
@group
This is a subsection
--------------------
@end group
@end example

In a printed manual, subsections are listed in the table of contents
and are numbered three levels deep.@refill

@node unnumberedsubsec appendixsubsec subheading, subsubsection, subsection, Structuring
@comment  node-name,  next,  previous,  up
@section The @code{@@subsection}-like Commands
@cindex Subsection-like commands
@findex unnumberedsubsec
@findex appendixsubsec
@findex subheading

The @code{@@unnumberedsubsec}, @code{@@appendixsubsec}, and
@code{@@subheading} commands are, respectively, the unnumbered,
appendix-like, and heading-like equivalents of the @code{@@subsection}
command.  (@xref{subsection, , @code{@@subsection}}.)@refill

In Info, the @code{@@subsection}-like commands generate a title
underlined with hyphens.  In a printed manual, an @code{@@subheading}
command produces a heading like that of a subsection except that it is
not numbered and does not appear in the table of contents.  Similarly,
an @code{@@unnumberedsubsec} command produces an unnumbered heading like
that of a subsection and an @code{@@appendixsubsec} command produces a
subsection-like heading labelled with a letter and numbers; both of
these commands produce headings that appear in the table of
contents.@refill

@node subsubsection, Raise/lower sections, unnumberedsubsec appendixsubsec subheading, Structuring
@comment  node-name,  next,  previous,  up
@section The `subsub' Commands
@cindex Subsub commands
@findex subsubsection
@findex unnumberedsubsubsec
@findex appendixsubsubsec
@findex subsubheading

The fourth and lowest level sectioning commands in Texinfo are the
`subsub' commands.  They are:@refill

@table @code
@item @@subsubsection
Subsubsections are to subsections as subsections are to sections.
(@xref{subsection, , @code{@@subsection}}.)  In a printed manual,
subsubsection titles appear in the table of contents and are numbered
four levels deep.@refill

@item @@unnumberedsubsubsec
Unnumbered subsubsection titles appear in the table of contents of a
printed manual, but lack numbers.  Otherwise, unnumbered
subsubsections are the same as subsubsections.  In Info, unnumbered
subsubsections look exactly like ordinary subsubsections.@refill

@item @@appendixsubsubsec
Conventionally, appendix commands are used only for appendices and are
lettered and numbered appropriately in a printed manual.  They also
appear in the table of contents.  In Info, appendix subsubsections look
exactly like ordinary subsubsections.@refill

@item @@subsubheading
The @code{@@subsubheading} command may be used anywhere that you need
a small heading that will not appear in the table of contents.  In
Info, subsubheadings look exactly like ordinary subsubsection
headings.@refill
@end table

In Info,  `subsub' titles are underlined with periods.
For example,@refill

@example
@@subsubsection This is a subsubsection
@end example

@noindent
produces

@example
@group
This is a subsubsection
.......................
@end group
@end example

@node Raise/lower sections, , subsubsection, Structuring
@comment  node-name,  next,  previous,  up
@section @code{@@raisesections} and @code{@@lowersections}
@findex raisesections
@findex lowersections
@cindex Raising and lowering sections
@cindex Sections, raising and lowering

The @code{@@raisesections} and @code{@@lowersections} commands raise and
lower the hierarchical level of chapters, sections, subsections and the
like.  The @code{@@raisesections} command changes sections to chapters,
subsections to sections, and so on.  The @code{@@lowersections} command
changes chapters to sections, sections to subsections, and so on.

An @code{@@lowersections} command is useful if you wish to include text
that is written as an outer or standalone Texinfo file in another
Texinfo file as an inner, included file.  If you write the command at
the beginning of the file, all your @code{@@chapter} commands are
formatted as if they were @code{@@section} commands, all your
@code{@@section} command are formatted as if they were
@code{@@subsection} commands, and so on.

@need 1000
@code{@@raisesections} raises a command one level in the chapter
structuring hierarchy:@refill

@example
@group
  @r{Change}           @r{To}

@@subsection     @@section,
@@section        @@chapter,
@@heading        @@chapheading,
          @r{etc.}
@end group
@end example

@need 1000
@code{@@lowersections} lowers a command one level in the chapter
structuring hierarchy:@refill

@example
@group
  @r{Change}           @r{To}

@@chapter        @@section,
@@subsection     @@subsubsection,
@@heading        @@subheading,
          @r{etc.}
@end group
@end example

An @code{@@raisesections} or @code{@@lowersections} command changes only
those structuring commands that follow the command in the Texinfo file.
Write an @code{@@raisesections} or @code{@@lowersections} command on a
line of its own.

An @code{@@lowersections} command cancels an @code{@@raisesections}
command, and vice versa.

Repeated use of the commands continue to raise or lower the hierarchical
level a step at a time.

An attempt to raise above `chapters' reproduces chapter commands; an
attempt to lower below `subsubsections' reproduces subsubsection
commands.

@node Nodes, Menus, Structuring, Top
@comment  node-name,  next,  previous,  up
@chapter Nodes

@dfn{Nodes} are the primary segments of a Texinfo file.  They do not
themselves impose a hierarchic or any other kind of structure on a file.
Nodes contain @dfn{node pointers} that name other nodes, and can contain
@dfn{menus} which are lists of nodes.  In Info, the movement commands
can carry you to a pointed-to node or to a node listed in a menu.  Node
pointers and menus provide structure for Info files just as chapters,
sections, subsections, and the like, provide structure for printed
books.@refill

@menu
* Two Paths::                   Different commands to structure
                                  Info output and printed output.
* Node Menu Illustration::      A diagram, and sample nodes and menus.
* node::                        How to write a node, in detail.
* makeinfo Pointer Creation::   How to create node pointers with @code{makeinfo}.
@end menu

@node Two Paths, Node Menu Illustration, Nodes, Nodes
@ifinfo
@heading Two Paths
@end ifinfo

The node and menu commands and the chapter structuring commands are
independent of each other:

@itemize @bullet
@item
In Info, node and menu commands provide structure.  The chapter
structuring commands generate headings with different kinds of
underlining---asterisks for chapters, hyphens for sections, and so on;
they do nothing else.@refill

@item
In @TeX{}, the chapter structuring commands generate chapter and section
numbers and tables of contents.  The node and menu commands provide
information for cross references; they do nothing else.@refill
@end itemize

You can use node pointers and menus to structure an Info file any way
you want; and you can write a Texinfo file so that its Info output has a
different structure than its printed output.  However, most Texinfo
files are written such that the structure for the Info output
corresponds to the structure for the printed output.  It is not
convenient to do otherwise.@refill

Generally, printed output is structured in a tree-like hierarchy in
which the chapters are the major limbs from which the sections branch
out.  Similarly, node pointers and menus are organized to create a
matching structure in the Info output.@refill

@node Node Menu Illustration, node, Two Paths, Nodes
@comment  node-name,  next,  previous,  up
@section Node and Menu Illustration

Here is a copy of the diagram shown earlier that illustrates a Texinfo
file with three chapters, each of which contains two sections.@refill

Note that the ``root'' is at the top of the diagram and the ``leaves''
are at the bottom.  This is how such a diagram is drawn conventionally;
it illustrates an upside-down tree.  For this reason, the root node is
called the `Top' node, and `Up' node pointers carry you closer to the
root.@refill

@example
@group
                          Top
                           |
         -------------------------------------
        |                  |                  |
     Chapter 1          Chapter 2          Chapter 3
        |                  |                  |
     --------           --------           --------
    |        |         |        |         |        |
 Section  Section   Section  Section   Section  Section
   1.1      1.2       2.1      2.2       3.1      3.2

@end group
@end example

Write the beginning of the node for Chapter 2 like this:@refill

@example
@group
@@node     Chapter 2,  Chapter 3, Chapter 1, top
@@comment  node-name,  next,      previous,  up
@end group
@end example

@noindent
This @code{@@node} line says that the name of this node is ``Chapter 2'', the
name of the `Next' node is ``Chapter 3'', the name of the `Previous'
node is ``Chapter 1'', and the name of the `Up' node is ``Top''.

@quotation
@strong{Please Note:} `Next' refers to the next node at the same
hierarchical level in the manual, not necessarily to the next node
within the Texinfo file.  In the Texinfo file, the subsequent node may
be at a lower level---a section-level node may follow a chapter-level
node, and a subsection-level node may follow a section-level node.
`Next' and `Previous' refer to nodes at the @emph{same} hierarchical
level.  (The `Top' node contains the exception to this rule.  Since the
`Top' node is the only node at that level, `Next' refers to the first
following node, which is almost always a chapter or chapter-level
node.)@refill
@end quotation

To go to Sections 2.1 and 2.2 using Info, you need a menu inside Chapter
2.  (@xref{Menus}.)  You would write the menu just
before the beginning of Section 2.1, like this:@refill

@example
@group
    @@menu
    * Sect. 2.1::    Description of this section.
    * Sect. 2.2::
    @@end menu
@end group
@end example

Write the node for Sect. 2.1 like this:@refill

@example
@group
    @@node     Sect. 2.1, Sect. 2.2, Chapter 2, Chapter 2
    @@comment  node-name, next,      previous,  up
@end group
@end example

In Info format, the `Next' and `Previous' pointers of a node usually
lead to other nodes at the same level---from chapter to chapter or from
section to section (sometimes, as shown, the `Previous' pointer points
up); an `Up' pointer usually leads to a node at the level above (closer
to the `Top' node); and a `Menu' leads to nodes at a level below (closer
to `leaves').  (A cross reference can point to a node at any level;
see @ref{Cross References}.)@refill

Usually, an @code{@@node} command and a chapter structuring command are
used in sequence, along with indexing commands.  (You may follow the
@code{@@node} line with a comment line that reminds you which pointer is
which.)@refill

Here is the beginning of the chapter in this manual called ``Ending a
Texinfo File''.  This shows an @code{@@node} line followed by a comment
line, an @code{@@chapter} line, and then by indexing lines.@refill

@example
@group
@@node    Ending a File, Structuring, Beginning a File, Top
@@comment node-name,     next,        previous,         up
@@chapter Ending a Texinfo File
@@cindex Ending a Texinfo file
@@cindex Texinfo file ending
@@cindex File ending
@end group
@end example

@node node, makeinfo Pointer Creation, Node Menu Illustration, Nodes
@comment  node-name,  next,  previous,  up
@section The @code{@@node} Command

@cindex Node, defined
A @dfn{node} is a segment of text that begins at an @code{@@node}
command and continues until the next @code{@@node} command.  The
definition of node is different from that for chapter or section.  A
chapter may contain sections and a section may contain subsections;
but a node cannot contain subnodes; the text of a node continues only
until the next @code{@@node} command in the file.  A node usually
contains only one chapter structuring command, the one that follows
the @code{@@node} line.  On the other hand, in printed output nodes
are used only for cross references, so a chapter or section may
contain any number of nodes.  Indeed, a chapter usually contains
several nodes, one for each section, subsection, and
subsubsection.@refill

To create a node, write an @code{@@node} command at the beginning of a
line, and follow it with four arguments, separated by commas, on the
rest of the same line.  These arguments are the name of the node, and
the names of the `Next', `Previous', and `Up' pointers, in that order.
You may insert spaces before each pointer if you wish; the spaces are
ignored.  You must write the name of the node, and the names of the
`Next', `Previous', and `Up' pointers, all on the same line.  Otherwise,
the formatters fail.  (@inforef{Top, info, info}, for more information
about nodes in Info.)@refill

Usually, you write one of the chapter-structuring command lines
immediately after an @code{@@node} line---for example, an
@code{@@section} or @code{@@subsection} line.  (@xref{Structuring
Command Types, , Types of Structuring Command}.)@refill

@quotation
@strong{Please note:} The GNU Emacs Texinfo mode updating commands work
only with Texinfo files in which @code{@@node} lines are followed by chapter
structuring lines.  @xref{Updating Requirements}.@refill
@end quotation

@TeX{} uses @code{@@node} lines to identify the names to use for cross
references.  For this reason, you must write @code{@@node} lines in a
Texinfo file that you intend to format for printing, even if you do not
intend to format it for Info.  (Cross references, such as the one at the
end of this sentence, are made with @code{@@xref} and its related
commands; see @ref{Cross References}.)@refill

@menu
* Node Names::                  How to choose node and pointer names.
* Writing a Node::              How to write an @code{@@node} line.
* Node Line Tips::              Keep names short.
* Node Line Requirements::      Keep names unique, without @@-commands.
* First Node::                  How to write a `Top' node.
* makeinfo top command::        How to use the @code{@@top} command.
* Top Node Summary::            Write a brief description for readers.
@end menu

@node Node Names, Writing a Node, node, node
@ifinfo
@subheading Choosing Node and Pointer Names
@end ifinfo

The name of a node identifies the node.  The pointers enable
you to reach other nodes and consist of the names of those nodes.@refill

Normally, a node's `Up' pointer contains the name of the node whose menu
mentions that node.  The node's `Next' pointer contains the name of the
node that follows that node in that menu and its `Previous' pointer
contains the name of the node that precedes it in that menu.  When a
node's `Previous' node is the same as its `Up' node, both node pointers
name the same node.@refill

Usually, the first node of a Texinfo file is the `Top' node, and its
`Up' and `Previous' pointers point to the @file{dir} file, which
contains the main menu for all of Info.@refill

The `Top' node itself contains the main or master menu for the manual.
Also, it is helpful to include a brief description of the manual in the
`Top' node.  @xref{First Node}, for information on how to write the
first node of a Texinfo file.@refill

@node Writing a Node, Node Line Tips, Node Names, node
@comment  node-name,  next,  previous,  up
@subsection How to Write an @code{@@node} Line
@cindex Writing an @code{@@node} line
@cindex @code{@@node} line writing
@cindex Node line writing

The easiest way to write an @code{@@node} line is to write @code{@@node}
at the beginning of a line and then the name of the node, like
this:@refill

@example
@@node @var{node-name}
@end example

If you are using GNU Emacs, you can use the update node commands
provided by Texinfo mode to insert the names of the pointers; or you
can leave the pointers out of the Texinfo file and let @code{makeinfo}
insert node pointers into the Info file it creates.  (@xref{Texinfo
Mode}, and @ref{makeinfo Pointer Creation}.)@refill

Alternatively, you can insert the `Next', `Previous', and `Up'
pointers yourself.  If you do this, you may find it helpful to use the
Texinfo mode keyboard command @kbd{C-c C-c n}.  This command inserts
@samp{@@node} and a comment line listing the names of the pointers in
their proper order.  The comment line helps you keep track of which
arguments are for which pointers.  This comment line is especially useful
if you are not familiar with Texinfo.@refill

The template for a node line with `Next', `Previous', and `Up' pointers
looks like this:@refill

@example
@@node @var{node-name}, @var{next}, @var{previous}, @var{up}
@end example

If you wish, you can ignore @code{@@node} lines altogether in your first
draft and then use the @code{texinfo-insert-node-lines} command to
create @code{@@node} lines for you.  However, we do not
recommend this practice.  It is better to name the node itself
at the same time that you
write a segment so you can easily make cross references.  A large number
of cross references are an especially important feature of a good Info
file.@refill

After you have inserted an @code{@@node} line, you should immediately
write an @@-command for the chapter or section and insert its name.
Next (and this is important!), put in several index entries.  Usually,
you will find at least two and often as many as four or five ways of
referring to the node in the index.  Use them all.  This will make it
much easier for people to find the node.@refill

@node Node Line Tips, Node Line Requirements, Writing a Node, node
@comment  node-name,  next,  previous,  up
@subsection @code{@@node} Line Tips

Here are three suggestions:

@itemize @bullet
@item
Try to pick node names that are informative but short.@refill

In the Info file, the file name, node name, and pointer names are all
inserted on one line, which may run into the right edge of the window.
(This does not cause a problem with Info, but is ugly.)@refill

@item
Try to pick node names that differ from each other near the beginnings
of their names.  This way, it is easy to use automatic name completion in
Info.@refill

@item
By convention, node names are capitalized just as they would be for
section or chapter titles---initial and significant words are
capitalized; others are not.@refill
@end itemize

@node Node Line Requirements, First Node, Node Line Tips, node
@comment  node-name,  next,  previous,  up
@subsection @code{@@node} Line Requirements

@cindex Node line requirements
Here are several requirements for @code{@@node} lines:

@itemize @bullet
@cindex Unique nodename requirement
@cindex Nodename must be unique
@item
All the node names for a single Info file must be unique.@refill

Duplicates confuse the Info movement commands.  This means, for
example, that if you end every chapter with a summary, you must name
each summary node differently.  You cannot just call each one
``Summary''.  You may, however, duplicate the titles of chapters, sections,
and the like.  Thus you can end each chapter in a book with a section
called ``Summary'', so long as the node names for those sections are all
different.@refill

@item
A pointer name must be the name of a node.@refill

The node to which a pointer points may come before or after the
node containing the pointer.@refill

@cindex @@-command in nodename
@cindex Nodename, cannot contain
@item
You cannot use any of the Texinfo @@-commands in a node name;
@w{@@-commands} confuse Info.@refill

@need 750
Thus, the beginning of the section called @code{@@chapter} looks like
this:@refill

@smallexample
@group
@@node  chapter, unnumbered & appendix, makeinfo top, Structuring
@@comment  node-name,  next,  previous,  up
@@section @@code@{@@@@chapter@}
@@findex chapter
@end group
@end smallexample

@cindex Comma in nodename
@cindex Colon in nodename
@cindex Apostrophe in nodename
@item
You cannot use commas, colons, or apostrophes within a node name; these
confuse @TeX{} or the Info formatters.@refill

@need 700
For example, the following is a section title:

@smallexample
@@code@{@@@@unnumberedsec@}, @@code@{@@@@appendixsec@}, @@code@{@@@@heading@}
@end smallexample

@noindent
The corresponding node name is:

@smallexample
unnumberedsec appendixsec heading
@end smallexample

@cindex Case in nodename
@item
Case is significant.
@end itemize

@node First Node, makeinfo top command, Node Line Requirements, node
@comment  node-name,  next,  previous,  up
@subsection The First Node
@cindex @samp{@r{Top}} node is first
@cindex First node

The first node of a Texinfo file is the `Top' node, except in an
included file (@pxref{Include Files}).

The `Top' node (which must be named @samp{top} or @samp{Top}) should
have as its `Up' and `Previous' nodes the name of a node in another
file, where there is a menu that leads to this file.  Specify the file
name in parentheses.  If the file is to be installed directly in the
Info directory file, use @samp{(dir)} as the parent of the `Top' node;
this is short for @samp{(dir)top}, and specifies the `Top' node in the
@file{dir} file, which contains the main menu for Info.  For example,
the @code{@@node Top} line of this manual looks like this:@refill

@example
@@node Top, Overview, (dir), (dir)
@end example

@noindent
(You may use the Texinfo updating commands or the @code{makeinfo}
utility to insert these `Next' and @samp{(dir)} pointers
automatically.)@refill

@xref{Install an Info File}, for more information about installing
an Info file in the @file{info} directory.@refill

The `Top' node contains the main or master menu for the document.

@node makeinfo top command, Top Node Summary, First Node, node
@comment  node-name,  next,  previous,  up
@subsection The @code{@@top} Sectioning Command
@findex top @r{(@@-command)}

A special sectioning command, @code{@@top}, has been created for use
with the @code{@@node Top} line.  The @code{@@top} sectioning command tells
@code{makeinfo} that it marks the `Top' node in the file.  It provides
the information that @code{makeinfo} needs to insert node
pointers automatically.  Write the @code{@@top} command at the
beginning of the line immediately following the @code{@@node Top}
line.  Write the title on the remaining part of the same line as the
@code{@@top} command.@refill

In Info, the @code{@@top} sectioning command causes the title to appear on a
line by itself, with a line of asterisks inserted underneath.@refill

In @TeX{} and @code{texinfo-format-buffer}, the @code{@@top}
sectioning command is merely a synonym for @code{@@unnumbered}.
Neither of these formatters require an @code{@@top} command, and do
nothing special with it.  You can use @code{@@chapter} or
@code{@@unnumbered} after the @code{@@node Top} line when you use
these formatters.  Also, you can use @code{@@chapter} or
@code{@@unnumbered} when you use the Texinfo updating commands to
create or update pointers and menus.@refill

@node Top Node Summary, , makeinfo top command, node
@subsection The `Top' Node Summary
@cindex @samp{@r{Top}} node summary

You can help readers by writing a summary in the `Top' node, after the
@code{@@top} line, before the main or master menu.  The summary should
briefly describe the document.  In Info, this summary will appear just
before the master menu.  In a printed manual, this summary will appear
on a page of its own.@refill

If you do not want the summary to appear on a page of its own in a
printed manual, you can enclose the whole of the `Top' node, including
the @code{@@node Top} line and the @code{@@top} sectioning command line
or other sectioning command line between @code{@@ifinfo} and @code{@@end
ifinfo}.  This prevents any of the text from appearing in the printed
output. (@pxref{Conditionals, , Conditionally Visible Text}).  You can
repeat the brief description from the `Top' node within @code{@@iftex}
@dots{} @code{@@end iftex} at the beginning of the first chapter, for
those who read the printed manual.  This saves paper and may look
neater.@refill

You should write the version number of the program to which the manual
applies in the summary.  This helps the reader keep track of which
manual is for which version of the program.  If the manual changes more
frequently than the program or is independent of it, you should also
include an edition number for the manual.  (The title page should also
contain this information: see @ref{titlepage, ,
@code{@@titlepage}}.)@refill

@node makeinfo Pointer Creation, , node, Nodes
@section Creating Pointers with @code{makeinfo}
@cindex Creating pointers with @code{makeinfo}
@cindex Pointer creation with @code{makeinfo}
@cindex Automatic pointer creation with @code{makeinfo}

The @code{makeinfo} program has a feature for automatically creating
node pointers for a hierarchically organized file that lacks
them.@refill

When you take advantage of this feature, you do not need to write the
`Next', `Previous', and `Up' pointers after the name of a node.
However, you must write a sectioning command, such as @code{@@chapter}
or @code{@@section}, on the line immediately following each truncated
@code{@@node} line.  You cannot write a comment line after a node
line; the section line must follow it immediately.@refill

In addition, you must follow the `Top' @code{@@node} line with a line beginning
with @code{@@top} to mark the `Top' node in the file. @xref{makeinfo
top, , @code{@@top}}.

Finally, you must write the name of each node (except for the `Top'
node) in a menu that is one or more hierarchical levels above the
node's hierarchical level.@refill

This node pointer insertion feature in @code{makeinfo} is an
alternative to the menu and pointer creation and update commands in
Texinfo mode.  (@xref{Updating Nodes and Menus}.)  It is especially
helpful to people who do not use GNU Emacs for writing Texinfo
documents.@refill

@node Menus, Cross References, Nodes, Top
@comment  node-name,  next,  previous,          up
@chapter Menus
@cindex Menus
@findex menu

@dfn{Menus} contain pointers to subordinate
nodes.@footnote{Menus can carry you to any node, regardless
of the hierarchical structure; even to nodes in a different
Info file.  However, the GNU Emacs Texinfo mode updating
commands work only to create menus of subordinate nodes.
Conventionally, cross references are used to refer to other
nodes.} In Info, you use menus to go to such nodes.  Menus
have no effect in printed manuals and do not appear in
them.@refill

By convention, a menu is put at the end of a node since a reader who
uses the menu may not see text that follows it.@refill

@ifinfo
A node that has a menu should @emph{not} contain much text.  If you
have a lot of text and a menu, move most of the text into a new
subnode---all but a few lines.@refill
@end ifinfo
@iftex
@emph{A node that has a menu should not contain much text.} If you
have a lot of text and a menu, move most of the text into a new
subnode---all but a few lines.  Otherwise, a reader with a terminal
that displays only a few lines may miss the menu and its associated
text.  As a practical matter, you should locate a menu within 20 lines
of the beginning of the node.@refill
@end iftex

@menu
* Menu Location::               Put a menu in a short node.
* Writing a Menu::              What is a menu?
* Menu Parts::                  A menu entry has three parts.
* Less Cluttered Menu Entry::   Two part menu entry.
* Menu Example::                Two and three part menu entries.
* Other Info Files::            How to refer to a different Info file.
@end menu

@node Menu Location, Writing a Menu, Menus, Menus
@ifinfo
@heading Menus Need Short Nodes
@end ifinfo
@cindex Menu location
@cindex Location of menus
@cindex Nodes for menus are short
@cindex Short nodes for menus

@ifinfo
A reader can easily see a menu that is close to the beginning of the
node.  The node should be short.  As a practical matter, you should
locate a menu within 20 lines of the beginning of the node.
Otherwise, a reader with a terminal that displays only a few lines may
miss the menu and its associated text.@refill
@end ifinfo

The short text before a menu may look awkward in a printed manual.  To
avoid this, you can write a menu near the beginning of its node and
follow the menu by an @code{@@node} line, and then an @code{@@heading}
line located within @code{@@ifinfo} and @code{@@end ifinfo}.  This way,
the menu, @code{@@node} line, and title appear only in the Info file,
not the printed document.@refill

For example, the preceding two paragraphs follow an Info-only menu,
@code{@@node} line, and heading, and look like this:@refill

@example
@group
@@menu
* Menu Location::             Put a menu in a short node.
* Writing a Menu::            What is a menu?
* Menu Parts::                A menu entry has three parts.
* Less Cluttered Menu Entry:: Two part menu entry.
* Menu Example::              Two and three part entries.
* Other Info Files::          How to refer to a different
                                Info file.
@@end menu

@@node Menu Location, Writing a Menu, , Menus
@@ifinfo
@@heading Menus Need Short Nodes
@@end ifinfo
@end group
@end example

The Texinfo file for this document contains more than a dozen
examples of this procedure.  One is at the beginning of this chapter;
another is at the beginning of the ``Cross References'' chapter.@refill

@node Writing a Menu, Menu Parts, Menu Location, Menus
@section Writing a Menu
@cindex Writing a menu
@cindex Menu writing

A menu consists of an @code{@@menu} command on a line by
itself followed by menu entry lines or menu comment lines
and then by an @code{@@end menu} command on a line by
itself.@refill

A menu looks like this:@refill

@example
@group
@@menu
Larger Units of Text

* Files::                       All about handling files.
* Multiples: Buffers.           Multiple buffers; editing
                                  several files at once.
@@end menu
@end group
@end example

In a menu, every line that begins with an @w{@samp{* }} is a
@dfn{menu entry}.  (Note the space after the asterisk.)  A
line that does not start with an @w{@samp{* }} may also
appear in a menu.  Such a line is not a menu entry but is a
menu comment line that appears in the Info file.  In
the example above, the line @samp{Larger Units of Text} is a
menu comment line; the two lines starting with @w{@samp{* }}
are menu entries.

@node Menu Parts, Less Cluttered Menu Entry, Writing a Menu, Menus
@section The Parts of a Menu
@cindex Parts of a menu
@cindex Menu parts
@cindex @code{@@menu} parts

A menu entry has three parts, only the second of which is
required:@refill

@enumerate
@item
The menu entry name.

@item
The name of the node (required).

@item
A description of the item.
@end enumerate

The template for a menu entry looks like this:@refill

@example
* @var{menu-entry-name}: @var{node-name}.   @var{description}
@end example

Follow the menu entry name with a single colon and follow the node name
with tab, comma, period, or newline.@refill

In Info, a user selects a node with the @kbd{m} (@code{Info-menu})
command.  The menu entry name is what the user types after the @kbd{m}
command.@refill

The third part of a menu entry is a descriptive phrase or
sentence.  Menu entry names and node names are often short; the
description explains to the reader what the node is about.  The
description, which is optional, can spread over two or more lines.  A
useful description complements the node name rather than repeats
it.@refill

@node Less Cluttered Menu Entry, Menu Example, Menu Parts, Menus
@comment  node-name,  next,  previous,  up
@section Less Cluttered Menu Entry
@cindex Two part menu entry
@cindex Double-colon menu entries
@cindex Menu entries with two colons
@cindex Less cluttered menu entry
@cindex Uncluttered menu entry

When the menu entry name and node name are the same, you can write
the name immediately after the asterisk and space at the beginning of
the line and follow the name with two colons.@refill

@need 800
For example, write

@example
* Name::                                    @var{description}
@end example

@need 800
@noindent
instead of

@example
* Name: Name.                               @var{description}
@end example

You should use the node name for the menu entry name whenever possible,
since it reduces visual clutter in the menu.@refill

@node Menu Example, Other Info Files, Less Cluttered Menu Entry, Menus
@comment  node-name,  next,  previous,  up
@section A Menu Example
@cindex Menu example
@cindex Example menu

A menu looks like this in Texinfo:@refill

@example
@group
@@menu
* menu entry name: Node name.   A short description.
* Node name::                   This form is preferred.
@@end menu
@end group
@end example

@need 800
@noindent
This produces:

@example
@group
* menu:

* menu entry name: Node name.   A short description.
* Node name::                   This form is preferred.
@end group
@end example

@need 700
Here is an example as you might see it in a Texinfo file:@refill

@example
@group
@@menu
Larger Units of Text

* Files::                       All about handling files.
* Multiples: Buffers.           Multiple buffers; editing
                                  several files at once.
@@end menu
@end group
@end example

@need 800
@noindent
This produces:

@example
@group
* menu:
Larger Units of Text

* Files::                       All about handling files.
* Multiples: Buffers.           Multiple buffers; editing
                                  several files at once.
@end group
@end example

In this example, the menu has two entries.  @samp{Files} is both a menu
entry name and the name of the node referred to by that name.
@samp{Multiples} is the menu entry name; it refers to the node named
@samp{Buffers}. The line @samp{Larger Units of Text} is a comment; it
appears in the menu, but is not an entry.@refill

Since no file name is specified with either @samp{Files} or
@samp{Buffers}, they must be the names of nodes in the same Info file
(@pxref{Other Info Files, , Referring to Other Info Files}).@refill

@node Other Info Files, , Menu Example, Menus
@comment  node-name,  next,  previous,  up
@section Referring to Other Info Files
@cindex Referring to other Info files
@cindex Nodes in other Info files
@cindex Other Info files' nodes
@cindex Going to other Info files' nodes
@cindex Info; other files' nodes

You can create a menu entry that enables a reader in Info to go to a
node in another Info file by writing the file name in parentheses just
before the node name.  In this case, you should use the three-part menu
entry format, which saves the reader from having to type the file
name.@refill

@need 800
The format looks like this:@refill

@example
@group
@@menu
* @var{first-entry-name}:(@var{filename})@var{nodename}.     @var{description}
* @var{second-entry-name}:(@var{filename})@var{second-node}. @var{description}
@@end menu
@end group
@end example

For example, to refer directly to the @samp{Outlining} and
@samp{Rebinding} nodes in the @cite{Emacs Manual}, you would write a
menu like this:@refill

@example
@group
@@menu
* Outlining: (emacs)Outline Mode. The major mode for
                                  editing outlines.
* Rebinding: (emacs)Rebinding.    How to redefine the
                                  meaning of a key.
@@end menu
@end group
@end example

If you do not list the node name, but only name the file, then Info
presumes that you are referring to the `Top' node.@refill

The @file{dir} file that contains the main menu for Info has menu
entries that list only file names.  These take you directly to the `Top'
nodes of each Info document.  (@xref{Install an Info File}.)@refill

@need 700
For example:

@example
@group
* Info: (info).         Documentation browsing system.
* Emacs: (emacs).       The extensible, self-documenting
                        text editor.
@end group
@end example

@noindent
(The @file{dir} top level directory for the Info system is an Info file,
not a Texinfo file, but a menu entry looks the same in both types of
file.)@refill

Note that the GNU Emacs Texinfo mode menu updating commands only work
with nodes within the current buffer, so you cannot use them to create
menus that refer to other files.  You must write such menus by hand.@refill

@node Cross References, Marking Text, Menus, Top
@comment  node-name,  next,  previous,  up
@chapter Cross References
@cindex Making cross references
@cindex Cross references
@cindex References

@dfn{Cross references} are used to refer the reader to other parts of the
same or different Texinfo files.  In Texinfo, nodes are the
places to which cross references can refer.@refill

@menu
* References::                  What cross references are for.
* Cross Reference Commands::    A summary of the different commands.
* Cross Reference Parts::       A cross reference has several parts.
* xref::                        Begin a reference with `See' @dots{}
* Top Node Naming::             How to refer to the beginning of another file.
* ref::                         A reference for the last part of a sentence.
* pxref::                       How to write a parenthetical cross reference.
* inforef::                     How to refer to an Info-only file.
@end menu

@node References, Cross Reference Commands, Cross References, Cross References
@ifinfo
@heading What References Are For
@end ifinfo

Often, but not always, a printed document should be designed so that
it can be read sequentially.  People tire of flipping back and forth
to find information that should be presented to them as they need
it.@refill

However, in any document, some information will be too detailed for
the current context, or incidental to it; use cross references to
provide access to such information.  Also, an on-line help system or a
reference manual is not like a novel; few read such documents in
sequence from beginning to end.  Instead, people look up what they
need.  For this reason, such creations should contain many cross
references to help readers find other information that they may not
have read.@refill

In a printed manual, a cross reference results in a page reference,
unless it is to another manual altogether, in which case the cross
reference names that manual.@refill

In Info, a cross reference results in an entry that you can follow using
the Info @samp{f} command.  (@inforef{Help-Adv, Some advanced Info
commands, info}.)@refill

The various cross reference commands use nodes to define cross
reference locations.  This is evident in Info, in which a cross
reference takes you to the specified node.  @TeX{} also uses nodes to
define cross reference locations, but the action is less obvious.  When
@TeX{} generates a @sc{dvi} file, it records nodes' page numbers and
uses the page numbers in making references.  Thus, if you are writing
a manual that will only be printed, and will not be used on-line, you
must nonetheless write @code{@@node} lines to name the places to which
you make cross references.@refill

@need 800
@node Cross Reference Commands, Cross Reference Parts, References, Cross References
@comment  node-name,  next,  previous,  up
@section Different Cross Reference Commands
@cindex Different cross reference commands

There are four different cross reference commands:@refill

@table @code
@item @@xref
Used to start a sentence in the printed manual saying @w{`See @dots{}'}
or an Info cross-reference saying @samp{*Note @var{name}: @var{node}.}.

@item @@ref
Used within or, more often, at the end of a sentence; same as
@code{@@xref} for Info; produces just the reference in the printed
manual without a preceding `See'.@refill

@item @@pxref
Used within parentheses to make a reference that suits both an Info
file and a printed book.  Starts with a lower case `see' within the
printed manual. (@samp{p} is for `parenthesis'.)@refill

@item @@inforef
Used to make a reference to an Info file for which there is no printed
manual.@refill
@end table

@noindent
(The @code{@@cite} command is used to make references to books and
manuals for which there is no corresponding Info file and, therefore,
no node to which to point.   @xref{cite, , @code{@@cite}}.)@refill

@node Cross Reference Parts, xref, Cross Reference Commands, Cross References
@comment  node-name,  next,  previous,  up
@section Parts of a Cross Reference
@cindex Cross reference parts
@cindex Parts of a cross reference

A cross reference command requires only one argument, which is the
name of the node to which it refers.  But a cross reference command
may contain up to four additional arguments.  By using these
arguments, you can provide a cross reference name for Info, a topic
description or section title for the printed output, the name of a
different Info file, and the name of a different printed
manual.@refill

Here is a simple cross reference example:@refill

@example
@@xref@{Node name@}.
@end example

@noindent
which produces

@example
*Note Node name::.
@end example

@noindent
and

@quotation
See Section @var{nnn} [Node name], page @var{ppp}.
@end quotation

@need 700
Here is an example of a full five-part cross reference:@refill

@example
@group
@@xref@{Node name, Cross Reference Name, Particular Topic,
info-file-name, A Printed Manual@}, for details.
@end group
@end example

@noindent
which produces

@example
*Note Cross Reference Name: (info-file-name)Node name,
for details.
@end example

@noindent
in Info and

@quotation
See section ``Particular Topic'' in @i{A Printed Manual}, for details.
@end quotation

@noindent
in a printed book.

The five possible arguments for a cross reference are:@refill

@enumerate
@item
The node name (required).  This is the node to which the
cross reference takes you.  In a printed document, the location of the
node provides the page reference only for references within the same
document.@refill

@item
The cross reference name for the Info reference, if it is to be different
from the node name.  If you include this argument, it argument becomes
the first part of the cross reference. It is usually omitted.@refill

@item
A topic description or section name.  Often, this is the title of the
section.  This is used as the name of the reference in the printed
manual.  If omitted, the node name is used.@refill

@item
The name of the Info file in which the reference is located, if it is
different from the current file.@refill

@item
The name of a printed manual from a different Texinfo file.@refill
@end enumerate

The template for a full five argument cross reference looks like
this:@refill

@example
@group
@@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic},
@var{info-file-name}, @var{printed-manual-title}@}.
@end group
@end example

Cross references with one, two, three, four, and five arguments are
described separately following the description of @code{@@xref}.@refill

Write a node name in a cross reference in exactly the same way as in
the @code{@@node} line, including the same capitalization; otherwise, the
formatters may not find the reference.@refill

You can write cross reference commands within a paragraph, but note
how Info and @TeX{} format the output of each of the various commands:
write @code{@@xref} at the beginning of a sentence; write
@code{@@pxref} only within parentheses, and so on.@refill

@node xref, Top Node Naming, Cross Reference Parts, Cross References
@comment  node-name,  next,  previous,  up
@section @code{@@xref}
@findex xref
@cindex Cross references using @code{@@xref}
@cindex References using @code{@@xref}

The @code{@@xref} command generates a cross reference for the
beginning of a sentence.  The Info formatting commands convert it into
an Info cross reference, which the Info @samp{f} command can use to
bring you directly to another node.  The @TeX{} typesetting commands
convert it into a page reference, or a reference to another book or
manual.@refill

@menu
* Reference Syntax::            What a reference looks like and requires.
* One Argument::                @code{@@xref} with one argument.
* Two Arguments::               @code{@@xref} with two arguments.
* Three Arguments::             @code{@@xref} with three arguments.
* Four and Five Arguments::     @code{@@xref} with four and five arguments.
@end menu

@node Reference Syntax, One Argument, xref, xref
@ifinfo
@subheading What a Reference Looks Like and Requires
@end ifinfo

Most often, an Info cross reference looks like this:@refill

@example
*Note @var{node-name}::.
@end example

@noindent
or like this

@example
*Note @var{cross-reference-name}: @var{node-name}.
@end example

@noindent
In @TeX{}, a cross reference looks like this:

@example
See Section @var{section-number} [@var{node-name}], page @var{page}.
@end example

@noindent
or like this

@example
See Section @var{section-number} [@var{title-or-topic}], page @var{page}.
@end example

The @code{@@xref} command does not generate a period or comma to end
the cross reference in either the Info file or the printed output.
You must write that period or comma yourself; otherwise, Info will not
recognize the end of the reference.  (The @code{@@pxref} command works
differently.  @xref{pxref, , @code{@@pxref}}.)@refill

@quotation
@strong{Please note:} A period or comma @strong{must} follow the closing
brace of an @code{@@xref}.  It is required to terminate the cross
reference.  This period or comma will appear in the output, both in
the Info file and in the printed manual.@refill
@end quotation

@code{@@xref} must refer to an Info node by name.  Use @code{@@node}
to define the node (@pxref{Writing a Node}).@refill

@code{@@xref} is followed by several arguments inside braces, separated by
commas.  Whitespace before and after these commas is ignored.@refill

A cross reference requires only the name of a node; but it may contain
up to four additional arguments.  Each of these variations produces a
cross reference that looks somewhat different.@refill

@quotation
@strong{Please note:} Commas separate arguments in a cross reference;
avoid including them in the title or other part lest the formatters
mistake them for separators.@refill
@end quotation

@node One Argument, Two Arguments, Reference Syntax, xref
@subsection @code{@@xref} with One Argument

The simplest form of @code{@@xref} takes one argument, the name of
another node in the same Info file.    The Info formatters produce
output that the Info readers can use to jump to the reference; @TeX{}
produces output that specifies the page and section number for you.@refill

@need 700
@noindent
For example,

@example
@@xref@{Tropical Storms@}.
@end example

@noindent
produces

@example
*Note Tropical Storms::.
@end example

@noindent
and

@quotation
See Section 3.1 [Tropical Storms], page 24.
@end quotation

@noindent
(Note that in the preceding example the closing brace is followed by a
period.)@refill

You can write a clause after the cross reference, like this:@refill

@example
@@xref@{Tropical Storms@}, for more info.
@end example

@noindent
which produces

@example
*Note Tropical Storms::, for more info.
@end example

@quotation
See Section 3.1 [Tropical Storms], page 24, for more info.
@end quotation

@noindent
(Note that in the preceding example the closing brace is followed by a
comma, and then by the clause, which is followed by a period.)@refill

@node Two Arguments, Three Arguments, One Argument, xref
@subsection @code{@@xref} with Two Arguments

With two arguments, the second is used as the name of the Info cross
reference, while the first is still the name of the node to which the
cross reference points.@refill

@need 750
@noindent
The template is like this:

@example
@@xref@{@var{node-name}, @var{cross-reference-name}@}.
@end example

@need 700
@noindent
For example,

@example
@@xref@{Electrical Effects, Lightning@}.
@end example

@noindent
produces:

@example
*Note Lightning: Electrical Effects.
@end example

@noindent
and

@quotation
See Section 5.2 [Electrical Effects], page 57.
@end quotation

@noindent
(Note that in the preceding example the closing brace is followed by a
period; and that the node name is printed, not the cross reference name.)@refill

You can write a clause after the cross reference, like this:@refill

@example
@@xref@{Electrical Effects, Lightning@}, for more info.
@end example

@noindent
which produces
@example
*Note Lightning: Electrical Effects, for more info.
@end example

@noindent
and

@quotation
See Section 5.2 [Electrical Effects], page 57, for more info.
@end quotation

@noindent
(Note that in the preceding example the closing brace is followed by a
comma, and then by the clause, which is followed by a period.)@refill

@node Three Arguments, Four and Five Arguments, Two Arguments, xref
@subsection @code{@@xref} with Three Arguments

A third argument replaces the node name in the @TeX{} output.  The third
argument should be the name of the section in the printed output, or
else state the topic discussed by that section.  Often, you will want to
use initial upper case letters so it will be easier to read when the
reference is printed.  Use a third argument when the node name is
unsuitable because of syntax or meaning.@refill

Remember to avoid placing a comma within the title or topic section of
a cross reference, or within any other section.  The formatters divide
cross references into arguments according to the commas; a comma
within a title or other section will divide it into two arguments.  In
a reference, you need to write a title such as ``Clouds, Mist, and
Fog'' without the commas.@refill

Also, remember to write a comma or period after the closing brace of a
@code{@@xref} to terminate the cross reference.  In the following
examples, a clause follows a terminating comma.@refill


@need 750
@noindent
The template is like this:

@example
@group
@@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}@}.
@end group
@end example

@need 700
@noindent
For example,

@example
@group
@@xref@{Electrical Effects, Lightning, Thunder and Lightning@},
for details.
@end group
@end example

@noindent
produces

@example
*Note Lightning: Electrical Effects, for details.
@end example

@noindent
and

@quotation
See Section 5.2 [Thunder and Lightning], page 57, for details.
@end quotation

If a third argument is given and the second one is empty, then the
third argument serves both.  (Note how two commas, side by side, mark
the empty second argument.)@refill

@example
@group
@@xref@{Electrical Effects, , Thunder and Lightning@},
for details.
@end group
@end example

@noindent
produces

@example
*Note Thunder and Lightning: Electrical Effects, for details.
@end example

@noindent
and

@quotation
See Section 5.2 [Thunder and Lightning], page 57, for details.
@end quotation

As a practical matter, it is often best to write cross references with
just the first argument if the node name and the section title are the
same, and with the first and third arguments if the node name and title
are different.@refill

Here are several examples from @cite{The GAWK Manual}:@refill

@smallexample
@@xref@{Sample Program@}.
@@xref@{Glossary@}.
@@xref@{Case-sensitivity, ,Case-sensitivity in Matching@}.
@@xref@{Close Output, , Closing Output Files and Pipes@},
   for more information.
@@xref@{Regexp, , Regular Expressions as Patterns@}.
@end smallexample

@node Four and Five Arguments, , Three Arguments, xref
@subsection @code{@@xref} with Four and Five Arguments

In a cross reference, a fourth argument specifies the name of another
Info file, different from the file in which the reference appears, and
a fifth argument specifies its title as a printed manual.@refill

Remember that a comma or period must follow the closing brace of an
@code{@@xref} command to terminate the cross reference.  In the
following examples, a clause follows a terminating comma.@refill

@need 800
@noindent
The template is:

@example
@group
@@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic},
@var{info-file-name}, @var{printed-manual-title}@}.
@end group
@end example

@need 700
@noindent
For example,

@example
@@xref@{Electrical Effects, Lightning, Thunder and Lightning,
weather, An Introduction to Meteorology@}, for details.
@end example

@noindent
produces

@example
*Note Lightning: (weather)Electrical Effects, for details.
@end example

@noindent
The name of the Info file is enclosed in parentheses and precedes
the name of the node.

@noindent
In a printed manual, the reference looks like this:@refill

@quotation
See section ``Thunder and Lightning'' in @i{An Introduction to
Meteorology}, for details.
@end quotation

@noindent
The title of the printed manual is typeset in italics; and the
reference lacks a page number since @TeX{} cannot know to which page a
reference refers when that reference is to another manual.@refill

Often, you will leave out the second argument when you use the long
version of @code{@@xref}.  In this case, the third argument, the topic
description, will be used as the cross reference name in Info.@refill

@noindent
The template looks like this:

@example
@@xref@{@var{node-name}, , @var{title-or-topic}, @var{info-file-name},
@var{printed-manual-title}@}, for details.
@end example

@noindent
which produces

@example
*Note @var{title-or-topic}: (@var{info-file-name})@var{node-name}, for details.
@end example

@noindent
and

@quotation
See section @var{title-or-topic} in @var{printed-manual-title}, for details.
@end quotation

@need 700
@noindent
For example,

@example
@@xref@{Electrical Effects, , Thunder and Lightning,
weather, An Introduction to Meteorology@}, for details.
@end example

@noindent
produces

@example
@group
*Note Thunder and Lightning: (weather)Electrical Effects,
for details.
@end group
@end example

@noindent
and

@quotation
See section ``Thunder and Lightning'' in @i{An Introduction to
Meteorology}, for details.
@end quotation

On rare occasions, you may want to refer to another Info file that
is within a single printed manual---when multiple Texinfo files are
incorporated into the same @TeX{} run but make separate Info files.
In this case, you need to specify only the fourth argument, and not
the fifth.@refill

@node Top Node Naming, ref, xref, Cross References
@section Naming a `Top' Node
@cindex Naming a `Top' Node in references
@cindex @samp{@r{Top}} node naming for references

In a cross reference, you must always name a node.  This means that in
order to refer to a whole manual, you must identify the `Top' node by
writing it as the first argument to the @code{@@xref} command.  (This
is different from the way you write a menu entry; see @ref{Other Info
Files, , Referring to Other Info Files}.)  At the same time, to
provide a meaningful section topic or title in the printed cross
reference (instead of the word `Top'), you must write an appropriate
entry for the third argument to the @code{@@xref} command.
@refill

@noindent
Thus, to make a cross reference to @cite{The GNU Make Manual},
write:@refill

@example
@@xref@{Top, , Overview, make, The GNU Make Manual@}.
@end example

@noindent
which produces

@example
*Note Overview: (make)Top.
@end example

@noindent
and

@quotation
See section ``Overview'' in @i{The GNU Make Manual}.
@end quotation

@noindent
In this example, @samp{Top} is the name of the first node, and
@samp{Overview} is the name of the first section of the manual.@refill
@node ref, pxref, Top Node Naming, Cross References
@comment  node-name,  next,  previous,  up
@section @code{@@ref}
@cindex Cross references using @code{@@ref}
@cindex References using @code{@@ref}
@findex ref

@code{@@ref} is nearly the same as @code{@@xref} except that it does
not generate a `See' in the printed output, just the reference itself.
This makes it useful as the last part of a sentence.@refill

@need 700
@noindent
For example,

@example
For more information, see @@ref@{Hurricanes@}.
@end example

@noindent
produces

@example
For more information, see *Note Hurricanes.
@end example

@noindent
and

@quotation
For more information, see Section 8.2 [Hurricanes], page 123.
@end quotation

The @code{@@ref} command sometimes leads writers to express themselves
in a manner that is suitable for a printed manual but looks awkward
in the Info format.  Bear in mind that your audience will be using
both the printed and the Info format.@refill

@need 800
@noindent
For example,

@example
@group
Sea surges are described in @@ref@{Hurricanes@}.
@end group
@end example

@need 800
@noindent
produces

@quotation
Sea surges are described in Section 6.7 [Hurricanes], page 72.
@end quotation

@need 800
@noindent
in a printed document, and the following in Info:

@example
Sea surges are described in *Note Hurricanes::.
@end example

@quotation
@strong{Caution:} You @emph{must} write a period or comma immediately
after an @code{@@ref} command with two or more arguments.  Otherwise,
Info will not find the end of the cross reference entry and its
attempt to follow the cross reference will fail.  As a general rule,
you should write a period or comma after every @code{@@ref} command.
This looks best in both the printed and the Info output.@refill
@end quotation

@node pxref, inforef, ref, Cross References
@comment  node-name,  next,  previous,  up
@section @code{@@pxref}
@cindex Cross references using @code{@@pxref}
@cindex References using @code{@@pxref}
@findex pxref

The parenthetical reference command, @code{@@pxref}, is nearly the
same as @code{@@xref}, but you use it @emph{only} inside parentheses
and you do @emph{not} type a comma or period after the command's
closing brace.  The command differs from @code{@@xref} in two
ways:@refill

@enumerate
@item
@TeX{} typesets the reference for the printed manual with a lower case
`see' rather than an upper case `See'.@refill

@item
The Info formatting commands automatically end the reference with a
closing colon or period.@refill
@end enumerate

Because one type of formatting automatically inserts closing
punctuation and the other does not, you should use @code{@@pxref}
@emph{only} inside parentheses as part of another sentence.  Also, you
yourself should not insert punctuation after the reference, as you do
with @code{@@xref}.@refill

@code{@@pxref} is designed so that the output looks right and works
right between parentheses both in printed output and in an Info file.
In a printed manual, a closing comma or period should not follow a
cross reference within parentheses; such punctuation is wrong.  But in
an Info file, suitable closing punctuation must follow the cross
reference so Info can recognize its end.  @code{@@pxref} spares you
the need to use complicated methods to put a terminator into one form
of the output and not the other.@refill

@noindent
With one argument, a parenthetical cross reference looks like
this:@refill

@example
@dots{} storms cause flooding (@@pxref@{Hurricanes@}) @dots{}
@end example

@need 800
@noindent
which produces

@example
@group
@dots{} storms cause flooding (*Note Hurricanes::) @dots{}
@end group
@end example

@noindent
and

@quotation
@dots{} storms cause flooding (see Section 6.7 [Hurricanes], page 72) @dots{}
@end quotation

With two arguments, a parenthetical cross reference has this
template:@refill

@example
@dots{} (@@pxref@{@var{node-name}, @var{cross-reference-name}@}) @dots{}
@end example

@noindent
which produces

@example
@dots{} (*Note @var{cross-reference-name}: @var{node-name}.) @dots{}
@end example

@noindent
and

@need 1500
@quotation
@dots{} (see Section @var{nnn} [@var{node-name}], page @var{ppp}) @dots{}
@end quotation

@code{@@pxref} can be used with up to five arguments just like
@code{@@xref} (@pxref{xref, , @code{@@xref}}).@refill

@quotation
@strong{Please note:} Use @code{@@pxref} only as a parenthetical
reference.  Do not try to use @code{@@pxref} as a clause in a sentence.
It will look bad in either the Info file, the printed output, or
both.@refill

Also, parenthetical cross references look best at the ends of sentences.
Although you may write them in the middle of a sentence, that location
breaks up the flow of text.@refill
@end quotation

@node inforef, , pxref, Cross References
@comment  node-name,  next,  previous,  up
@section @code{@@inforef}
@cindex Cross references using @code{@@inforef}
@cindex References using @code{@@inforef}
@findex inforef

@code{@@inforef} is used for cross references to Info files for which
there are no printed manuals.  Even in a printed manual,
@code{@@inforef} generates a reference directing the user to look in
an Info file.@refill

The command takes either two or three arguments, in the following
order:@refill

@enumerate
@item
The node name.

@item
The cross reference name (optional).

@item
The Info file name.
@end enumerate

@noindent
Separate the arguments with commas, as with @code{@@xref}.  Also, you
must terminate the reference with a comma or period after the
@samp{@}}, as you do with @code{@@xref}.@refill

@noindent
The template is:

@example
@@inforef@{@var{node-name}, @var{cross-reference-name}, @var{info-file-name}@},
@end example

@need 800
@noindent
Thus,

@example
@group
@@inforef@{Expert, Advanced Info commands, info@},
for more information.
@end group
@end example

@need 800
@noindent
produces

@example
@group
*Note Advanced Info commands: (info)Expert,
for more information.
@end group
@end example

@need 800
@noindent
and

@quotation
See Info file @file{info}, node @samp{Expert}, for more information.
@end quotation

@need 800
@noindent
Similarly,

@example
@group
@@inforef@{Expert, , info@}, for more information.
@end group
@end example

@need 800
@noindent
produces

@example
*Note (info)Expert::, for more information.
@end example

@need 800
@noindent
and

@quotation
See Info file @file{info}, node @samp{Expert}, for more information.
@end quotation

The converse of @code{@@inforef} is @code{@@cite}, which is used to
refer to printed works for which no Info form exists.  @xref{cite, ,
@code{@@cite}}.@refill

@node Marking Text, Quotations and Examples, Cross References, Top
@comment  node-name,  next,  previous,  up
@chapter Marking Words and Phrases
@cindex Paragraph, marking text within
@cindex Marking words and phrases
@cindex Words and phrases, marking them
@cindex Marking text within a paragraph

In Texinfo, you can mark words and phrases in a variety of ways.
The Texinfo formatters use this information to determine how to
highlight the text.
You can specify, for example, whether a word or phrase is a
defining occurrence, a metasyntactic variable, or a symbol used in a
program.  Also, you can emphasize text.@refill

@menu
* Indicating::                  How to indicate definitions, files, etc.
* Emphasis::                    How to emphasize text.
@end menu

@node Indicating, Emphasis, Marking Text, Marking Text
@comment  node-name,  next,  previous,  up
@section Indicating Definitions, Commands, etc.
@cindex Highlighting text
@cindex Indicating commands, definitions, etc.

Texinfo has commands for indicating just what kind of object a piece of
text refers to.  For example, metasyntactic variables are marked by
@code{@@var}, and code by @code{@@code}.  Since the pieces of text are
labelled by commands that tell what kind of object they are, it is easy
to change the way the Texinfo formatters prepare such text.  (Texinfo is
an @emph{intentional} formatting language rather than a @emph{typesetting}
formatting language.)@refill

For example, in a printed manual,
code is usually illustrated in a typewriter font;
@code{@@code} tells @TeX{} to typeset this text in this font.  But it
would be easy to change the way @TeX{} highlights code to use another
font, and this change would not effect how keystroke examples are
highlighted.  If straight typesetting commands were used in the body
of the file and you wanted to make a change, you would need to check
every single occurrence to make sure that you were changing code and
not something else that should not be changed.@refill

@menu
* Useful Highlighting::         Highlighting provides useful information.
* code::                        How to indicate code.
* kbd::                         How to show keyboard input.
* key::                         How to specify keys.
* samp::                        How to show a literal sequence of characters.
* var::                         How to indicate a metasyntactic variable.
* file::                        How to indicate the name of a file.
* dfn::                         How to specify a definition.
* cite::                        How to refer to a book that is not in Info.
* url::                         How to indicate a world wide web reference.
* email::                       How to indicate an electronic mail address.
@end menu

@node Useful Highlighting, code, Indicating, Indicating
@ifinfo
@subheading Highlighting Commands are Useful
@end ifinfo

The highlighting commands can be used to generate useful information
from the file, such as lists of functions or file names.  It is
possible, for example, to write a program in Emacs Lisp (or a keyboard
macro) to insert an index entry after every paragraph that contains
words or phrases marked by a specified command.  You could do this to
construct an index of functions if you had not already made the
entries.@refill

The commands serve a variety of purposes:@refill

@table @code
@item @@code@{@var{sample-code}@}
Indicate text that is a literal example of a piece of a program.@refill

@item @@kbd@{@var{keyboard-characters}@}
Indicate keyboard input.@refill

@item @@key@{@var{key-name}@}
Indicate the conventional name for a key on a keyboard.@refill

@item @@samp@{@var{text}@}
Indicate text that is a literal example of a sequence of characters.@refill

@item @@var@{@var{metasyntactic-variable}@}
Indicate a metasyntactic variable.@refill

@item @@url@{@var{uniform-resource-locator}@}
Indicate a uniform resource locator for the World Wide Web.

@item @@file@{@var{file-name}@}
Indicate the name of a file.@refill

@item @@email@{@var{email-address}@}
Indicate an electronic mail address.

@item @@dfn@{@var{term}@}
Indicate the introductory or defining use of a term.@refill

@item @@cite@{@var{reference}@}
Indicate the name of a book.@refill

@ignore
@item @@ctrl@{@var{ctrl-char}@}
Use for an @sc{ascii} control character.@refill
@end ignore
@end table

@node code, kbd, Useful Highlighting, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@code}@{@var{sample-code}@}
@findex code

Use the @code{@@code} command to indicate text that is a piece of a
program and which consists of entire syntactic tokens.  Enclose the
text in braces.@refill

Thus, you should use @code{@@code} for an expression in a program, for
the name of a variable or function used in a program, or for a
keyword.  Also, you should use @code{@@code} for the name of a
program, such as @code{diff}, that is a name used in the machine. (You
should write the name of a program in the ordinary text font if you
regard it as a new English word, such as `Emacs' or `Bison'.)@refill

Use @code{@@code} for environment variables such as @code{TEXINPUTS},
and other variables.@refill

Use @code{@@code} for command names in command languages that
resemble programming languages, such as Texinfo or the shell.
For example, @code{@@code} and @code{@@samp} are produced by writing
@samp{@@code@{@@@@code@}} and @samp{@@code@{@@@@samp@}} in the Texinfo
source, respectively.@refill

Note, however, that you should not use @code{@@code} for shell options
such as @samp{-c} when such options stand alone. (Use @code{@@samp}.)
Also, an entire shell command often looks better if written using
@code{@@samp} rather than @code{@@code}.  In this case, the rule is to
choose the more pleasing format.@refill

It is incorrect to alter the case of a word inside an @code{@@code}
command when it appears at the beginning of a sentence.  Most computer
languages are case sensitive.  In C, for example, @code{Printf} is
different from the identifier @code{printf}, and most likely is a
misspelling of it.  Even in languages which are not case sensitive, it
is confusing to a human reader to see identifiers spelled in different
ways.  Pick one spelling and always use that.  If you do not want to
start a sentence with a command written all in lower case, you should
rearrange the sentence.@refill

Do not use the @code{@@code} command for a string of characters shorter
than a syntactic token.  If you are writing about @samp{TEXINPU}, which
is just a part of the name for the @code{TEXINPUTS} environment
variable, you should use @code{@@samp}.@refill

In particular, you should not use the @code{@@code} command when writing
about the characters used in a token; do not, for example, use
@code{@@code} when you are explaining what letters or printable symbols
can be used in the names of functions.  (Use @code{@@samp}.)  Also, you
should not use @code{@@code} to mark text that is considered input to
programs unless the input is written in a language that is like a
programming language.  For example, you should not use @code{@@code} for
the keystroke commands of GNU Emacs (use @code{@@kbd} instead) although
you may use @code{@@code} for the names of the Emacs Lisp functions that
the keystroke commands invoke.@refill

In the printed manual, @code{@@code} causes @TeX{} to typeset the
argument in a typewriter face.  In the Info file, it causes the Info
formatting commands to use single quotation marks around the text.

@need 700
For example,

@example
Use @@code@{diff@} to compare two files.
@end example

@noindent
produces this in the printed manual:@refill

@quotation
Use @code{diff} to compare two files.
@end quotation
@iftex

@noindent
and this in the Info file:@refill

@example
Use `diff' to compare two files.
@end example
@end iftex

@node kbd, key, code, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@kbd}@{@var{keyboard-characters}@}
@findex kbd

Use the @code{@@kbd} command for characters of input to be typed by
users.  For example, to refer to the characters @kbd{M-a},
write@refill

@example
@@kbd@{M-a@}
@end example

@noindent
and to refer to the characters @kbd{M-x shell}, write@refill

@example
@@kbd@{M-x shell@}
@end example

The @code{@@kbd} command has the same effect as @code{@@code} in Info,
but may produce a different font in a printed manual.@refill

You can embed another @@-command inside the braces of an @code{@@kbd}
command.  Here, for example, is the way to describe a command that
would be described more verbosely as ``press an @samp{r} and then
press the @key{RET} key'':@refill

@example
@@kbd@{r @@key@{RET@}@}
@end example

@noindent
This produces: @kbd{r @key{RET}}

You also use the @code{@@kbd} command if you are spelling out the letters
you type; for example:@refill

@example
To give the @@code@{logout@} command,
type the characters @@kbd@{l o g o u t @@key@{RET@}@}.
@end example

@noindent
This produces:

@quotation
To give the @code{logout} command,
type the characters @kbd{l o g o u t @key{RET}}.
@end quotation

(Also, this example shows that you can add spaces for clarity.  If you
really want to mention a space character as one of the characters of
input, write @kbd{@@key@{SPC@}} for it.)@refill

@node key, samp, kbd, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@key}@{@var{key-name}@}
@findex key

Use the @code{@@key} command for the conventional name for a key on a
keyboard, as in:@refill

@example
@@key@{RET@}
@end example

You can use the @code{@@key} command within the argument of an
@code{@@kbd} command when the sequence of characters to be typed
includes one or more keys that are described by name.@refill

@need 700
For example, to produce @kbd{C-x @key{ESC}} you would type:@refill

@example
@@kbd@{C-x @@key@{ESC@}@}
@end example

Here is a list of the recommended names for keys:
@cindex Recommended names for keys
@cindex Keys, recommended names
@cindex Names recommended for keys
@cindex Abbreviations for keys

@quotation
@table @t
@item SPC
Space
@item RET
Return
@item LFD
Linefeed (however, since most keyboards nowadays do not have a Linefeed key,
it might be better to call this character @kbd{C-j}.
@item TAB
Tab
@item BS
Backspace
@item ESC
Escape
@item DEL
Delete
@item SHIFT
Shift
@item CTRL
Control
@item META
Meta
@end table
@end quotation

@cindex META key
There are subtleties to handling words like `meta' or `ctrl' that are
names of shift keys.  When mentioning a character in which the shift key
is used, such as @kbd{Meta-a}, use the @code{@@kbd} command alone; do
not use the @code{@@key} command; but when you are referring to the
shift key in isolation, use the @code{@@key} command.  For example,
write @samp{@@kbd@{Meta-a@}} to produce @kbd{Meta-a} and
@samp{@@key@{META@}} to produce @key{META}.

@c I don't think this is a good explanation.
@c I think it will puzzle readers more than it clarifies matters.  -- rms.
@c In other words, use @code{@@kbd} for what you do, and use @code{@@key}
@c for what you talk about: ``Press @code{@@kbd@{M-a@}} to move point to
@c the beginning of the sentence.  The @code{@@key@{META@}} key is often in
@c the lower left of the keyboard.''@refill

@node samp, var, key, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@samp}@{@var{text}@}
@findex samp

Use the @code{@@samp} command to indicate text that is a literal example
or `sample' of a sequence of characters in a file, string, pattern, etc.
Enclose the text in braces.  The argument appears within single
quotation marks in both the Info file and the printed manual; in
addition, it is printed in a fixed-width font.@refill

@example
To match @@samp@{foo@} at the end of the line,
use the regexp @@samp@{foo$@}.
@end example

@noindent
produces

@quotation
To match @samp{foo} at the end of the line, use the regexp
@samp{foo$}.@refill
@end quotation

Any time you are referring to single characters, you should use
@code{@@samp} unless @code{@@kbd} is more appropriate.  Use
@code{@@samp} for the names of command-line options.  Also, you may use
@code{@@samp} for entire statements in C and for entire shell
commands---in this case, @code{@@samp} often looks better than
@code{@@code}.  Basically, @code{@@samp} is a catchall for whatever is
not covered by @code{@@code}, @code{@@kbd}, or @code{@@key}.@refill

Only include punctuation marks within braces if they are part of the
string you are specifying.  Write punctuation marks outside the braces
if those punctuation marks are part of the English text that surrounds
the string.  In the following sentence, for example, the commas and
period are outside of the braces:@refill

@example
@group
In English, the vowels are @@samp@{a@}, @@samp@{e@},
@@samp@{i@}, @@samp@{o@}, @@samp@{u@}, and sometimes
@@samp@{y@}.
@end group
@end example

@noindent
This produces:

@quotation
In English, the vowels are @samp{a}, @samp{e},
@samp{i}, @samp{o}, @samp{u},  and sometimes
@samp{y}.
@end quotation

@node var, file, samp, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@var}@{@var{metasyntactic-variable}@}
@findex var

Use the @code{@@var} command to indicate metasyntactic variables.  A
@dfn{metasyntactic variable} is something that stands for another piece of
text.  For example, you should use a metasyntactic variable in the
documentation of a function to describe the arguments that are passed
to that function.@refill

Do not use @code{@@var} for the names of particular variables in
programming languages.  These are specific names from a program, so
@code{@@code} is correct for them.  For example, the Lisp variable
@code{texinfo-tex-command} is not a metasyntactic variable; it is
properly formatted using @code{@@code}.@refill

The effect of @code{@@var} in the Info file is to change the case of
the argument to all upper case; in the printed manual, to italicize it.

@need 700
For example,

@example
To delete file @@var@{filename@},
type @@code@{rm @@var@{filename@}@}.
@end example

@noindent
produces

@quotation
To delete file @var{filename}, type @code{rm @var{filename}}.
@end quotation

@noindent
(Note that @code{@@var} may appear inside @code{@@code},
@code{@@samp}, @code{@@file}, etc.)@refill

Write a metasyntactic variable all in lower case without spaces, and
use hyphens to make it more readable.  Thus, the Texinfo source for
the illustration of how to begin a Texinfo manual looks like
this:@refill

@example
@group
\input texinfo
@@@@setfilename @@var@{info-file-name@}
@@@@settitle @@var@{name-of-manual@}
@end group
@end example

@noindent
This produces:

@example
@group
\input texinfo
@@setfilename @var{info-file-name}
@@settitle @var{name-of-manual}
@end group
@end example

In some documentation styles, metasyntactic variables are shown with
angle brackets, for example:@refill

@example
@dots{}, type rm <filename>
@end example

@noindent
However, that is not the style that Texinfo uses.  (You can, of
course, modify the sources to @TeX{} and the Info formatting commands
to output the @code{<@dots{}>} format if you wish.)@refill

@node file, dfn, var, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@file}@{@var{file-name}@}
@findex file

Use the @code{@@file} command to indicate text that is the name of a
file, buffer, or directory, or is the name of a node in Info.  You can
also use the command for file name suffixes.  Do not use @code{@@file}
for symbols in a programming language; use @code{@@code}.

Currently, @code{@@file} is equivalent to @code{@@samp} in its effects.
For example,@refill

@example
The @@file@{.el@} files are in
the @@file@{/usr/local/emacs/lisp@} directory.
@end example

@noindent
produces

@quotation
The @file{.el} files are in
the @file{/usr/local/emacs/lisp} directory.
@end quotation

@node dfn, cite, file, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@dfn}@{@var{term}@}
@findex dfn

Use the @code{@@dfn} command to identify the introductory or defining
use of a technical term.  Use the command only in passages whose
purpose is to introduce a term which will be used again or which the
reader ought to know.  Mere passing mention of a term for the first
time does not deserve @code{@@dfn}.  The command generates italics in
the printed manual, and double quotation marks in the Info file.  For
example:@refill

@example
Getting rid of a file is called @@dfn@{deleting@} it.
@end example

@noindent
produces

@quotation
Getting rid of a file is called @dfn{deleting} it.
@end quotation

As a general rule, a sentence containing the defining occurrence of a
term should be a definition of the term.  The sentence does not need
to say explicitly that it is a definition, but it should contain the
information of a definition---it should make the meaning clear.

@node cite, url, dfn, Indicating
@comment  node-name,  next,  previous,  up
@subsection @code{@@cite}@{@var{reference}@}
@findex cite

Use the @code{@@cite} command for the name of a book that lacks a
companion Info file. The command produces italics in the printed
manual, and quotation marks in the Info file.@refill

(If a book is written in Texinfo, it is better to use a cross reference
command since a reader can easily follow such a reference in Info.
@xref{xref, , @code{@@xref}}.)@refill

@ignore
@c node ctrl, , cite, Indicating
@comment  node-name,  next,  previous,  up
@c subsection @code{@@ctrl}@{@var{ctrl-char}@}
@findex ctrl

The @code{@@ctrl} command is seldom used.  It describes an @sc{ascii}
control character by inserting the actual character into the Info
file.

Usually, in Texinfo, you talk what you type as keyboard entry by
describing it with @code{@@kbd}: thus, @samp{@@kbd@{C-a@}} for
@kbd{C-a}.  Use @code{@@kbd} in this way when talking about a control
character that is typed on the keyboard by the user.  When talking
about a control character appearing in a file or a string, do not use
@code{@@kbd} since the control character is not typed.  Also, do not
use @samp{C-} but spell out @code{control-}, as in @samp{control-a},
to make it easier for a reader to understand.@refill

@code{@@ctrl} is an idea from the beginnings of Texinfo which may not
really fit in to the scheme of things.  But there may be times when
you want to use the command.  The pattern is
@code{@@ctrl@{@var{ch}@}}, where @var{ch} is an @sc{ascii} character
whose control-equivalent is wanted.  For example, to specify
@samp{control-f}, you would enter@refill

@example
@@ctrl@{f@}
@end example

@noindent
produces

@quotation
@ctrl{f}
@end quotation

In the Info file, this generates the specified control character, output
literally into the file.  This is done so a user can copy the specified
control character (along with whatever else he or she wants) into another
Emacs buffer and use it.  Since the `control-h',`control-i', and
`control-j' characters are formatting characters, they should not be
indicated with @code{@@ctrl}.@refill

In a printed manual, @code{@@ctrl} generates text to describe or
identify that control character: an uparrow followed by the character
@var{ch}.@refill
@end ignore

@node url, email, cite, Indicating
@subsection @code{@@url}@{@var{uniform-resource-locator}@}
@findex url

Use the @code{@@url} command to indicate a uniform resource locator on
the World Wide Web.  For example:

@c Two lines because one is too long for smallbook format.
@example
The official GNU ftp site is
@@url@{ftp://ftp.gnu.ai.mit.edu/pub/gnu@}.
@end example

In Info and @TeX{}, this acts like @code{@@samp}.  When
Texinfo is converted to HTML, this produces a link you can follow.

@node email, , url, Indicating
@subsection @code{@@email}@{@var{email-address}@}
@findex email

Use the @code{@@email} command to indicate an electronic mail address.
For example:

@example
Send bug reports to @email{bug-texinfo@@prep.ai.mit.edu}.
@end example

In Info and @TeX{}, this acts like @code{@@samp}.  When we have support
for conversion of Texinfo to HTML, this will produce a link you can
follow to bring up a mail composition window initialized with
@var{email-address}.

@node Emphasis, , Indicating, Marking Text
@comment node-name,  next,  previous,  up
@section Emphasizing Text
@cindex Emphasizing text

Usually, Texinfo changes the font to mark words in the text according to
what category the words belong to; an example is the @code{@@code} command.
Most often, this is the best way to mark words.
However, sometimes you will want to emphasize text without indicating a
category.  Texinfo has two commands to do this.  Also, Texinfo has
several commands that specify the font in which @TeX{} will typeset
text.  These commands have no affect on Info and only one of them,
the @code{@@r} command, has any regular use.@refill

@menu
* emph & strong::               How to emphasize text in Texinfo.
* Smallcaps::                   How to use the small caps font.
* Fonts::                       Various font commands for printed output.
* Customized Highlighting::     How to define highlighting commands.
@end menu

@node emph & strong, Smallcaps, Emphasis, Emphasis
@comment  node-name,  next,  previous,  up
@subsection @code{@@emph}@{@var{text}@} and @code{@@strong}@{@var{text}@}
@cindex Emphasizing text, font for
@findex emph
@findex strong

The @code{@@emph} and @code{@@strong} commands are for emphasis;
@code{@@strong} is stronger.  In printed output, @code{@@emph}
produces @emph{italics} and @code{@@strong} produces
@strong{bold}.@refill

@need 800
For example,

@example
@group
@@quotation
@@strong@{Caution:@} @@code@{rm * .[^.]*@} removes @@emph@{all@}
files in the directory.
@@end quotation
@end group
@end example

@iftex
@noindent
produces the following in printed output:

@quotation
@strong{Caution}: @code{rm * .[^.]*} removes @emph{all}
files in the directory.
@end quotation

@noindent
and the following in Info:
@end iftex
@ifinfo
@noindent
produces:
@end ifinfo

@example
     *Caution*: `rm * .[^.]*' removes *all*
     files in the directory.
@end example

The @code{@@strong} command is seldom used except to mark what is, in
effect, a typographical element, such as the word `Caution' in the
preceding example.

In the Info file, both @code{@@emph} and @code{@@strong} put asterisks
around the text.@refill

@quotation
@strong{Caution:} Do not use @code{@@emph} or @code{@@strong} with the
word @samp{Note}; Info will mistake the combination for a cross
reference.  Use a phrase such as @strong{Please note} or
@strong{Caution} instead.@refill
@end quotation

@node Smallcaps, Fonts, emph & strong, Emphasis
@subsection @code{@@sc}@{@var{text}@}: The Small Caps Font
@cindex Small caps font
@findex sc @r{(small caps font)}

@iftex
Use the @samp{@@sc} command to set text in the printed output in @sc{a
small caps font} and set text in the Info file in upper case letters.@refill
@end iftex
@ifinfo
Use the @samp{@@sc} command to set text in the printed output in a
small caps font and set text in the Info file in upper case letters.@refill
@end ifinfo

Write the text between braces in lower case, like this:@refill

@example
The @@sc@{acm@} and @@sc@{ieee@} are technical societies.
@end example

@noindent
This produces:

@display
The @sc{acm} and @sc{ieee} are technical societies.
@end display

@TeX{} typesets the small caps font in a manner that prevents the
letters from `jumping out at you on the page'.  This makes small caps
text easier to read than text in all upper case.  The Info formatting
commands set all small caps text in upper case.@refill

@ifinfo
If the text between the braces of an @code{@@sc} command is upper case,
@TeX{} typesets in full-size capitals.  Use full-size capitals
sparingly.@refill
@end ifinfo
@iftex
If the text between the braces of an @code{@@sc} command is upper case,
@TeX{} typesets in @sc{FULL-SIZE CAPITALS}.  Use full-size capitals
sparingly.@refill
@end iftex

You may also use the small caps font for a jargon word such as
@sc{ato} (a @sc{nasa} word meaning `abort to orbit').@refill

There are subtleties to using the small caps font with a jargon word
such as @sc{cdr}, a word used in Lisp programming.  In this case, you
should use the small caps font when the word refers to the second and
subsequent elements of a list (the @sc{cdr} of the list), but you
should use @samp{@@code} when the word refers to the Lisp function of
the same spelling.@refill

@node Fonts, Customized Highlighting, Smallcaps, Emphasis
@comment node-name,  next,  previous,  up
@subsection Fonts for Printing, Not Info
@cindex Fonts for printing, not for Info
@findex i @r{(italic font)}
@findex b @r{(bold font)}
@findex t @r{(typewriter font)}
@findex r @r{(Roman font)}

Texinfo provides four font commands that specify font changes in the
printed manual but have no effect in the Info file.  @code{@@i}
requests @i{italic} font (in some versions of @TeX{}, a slanted font
is used), @code{@@b} requests @b{bold} face, @code{@@t} requests the
@t{fixed-width}, typewriter-style font used by @code{@@code}, and @code{@@r} requests a
@r{roman} font, which is the usual font in which text is printed.  All
four commands apply to an argument that follows, surrounded by
braces.@refill

Only the @code{@@r} command has much use: in example programs, you
can use the @code{@@r} command to convert code comments from the
fixed-width font to a roman font.  This looks better in printed
output.@refill

@need 700
For example,

@example
@group
@@lisp
(+ 2 2)    ; @@r@{Add two plus two.@}
@@end lisp
@end group
@end example

@noindent
produces

@lisp
(+ 2 2)    ; @r{Add two plus two.}
@end lisp

If possible, you should avoid using the other three font commands.  If
you need to use one, it probably indicates a gap in the Texinfo
language.@refill

@node Customized Highlighting, , Fonts, Emphasis
@comment node-name,  next,  previous,  up
@subsection Customized Highlighting
@cindex Highlighting, customized
@cindex Customized highlighting

@c I think this whole section is obsolete with the advent of macros
@c --karl, 15sep96.
You can use regular @TeX{} commands inside of @code{@@iftex} @dots{}
@code{@@end iftex} to create your own customized highlighting commands
for Texinfo.  The easiest way to do this is to equate your customized
commands with pre-existing commands, such as those for italics.  Such
new commands work only with @TeX{}.@refill

@findex definfoenclose
@cindex Enclosure command for Info
You can use the @code{@@definfoenclose} command inside of
@code{@@ifinfo} @dots{} @code{@@end ifinfo} to define commands for Info
with the same names as new commands for @TeX{}.
@code{@@definfoenclose} creates new commands for Info that mark text by
enclosing it in strings that precede and follow the text.
@footnote{Currently, @code{@@definfoenclose} works only with
@code{texinfo-format-buffer} and @code{texinfo-format-region}, not with
@code{makeinfo}.}@refill

Here is how to create a new @@-command called @code{@@phoo} that causes
@TeX{} to typeset its argument in italics and causes Info to display the
argument between @samp{//} and @samp{\\}.@refill

@need 1300
For @TeX{}, write the following to equate the @code{@@phoo} command with
the existing @code{@@i} italics command:@refill

@example
@group
@@iftex
@@global@@let@@phoo=@@i
@@end iftex
@end group
@end example

@noindent
This defines @code{@@phoo} as a command that causes @TeX{} to typeset
the argument to @code{@@phoo} in italics.  @code{@@global@@let} tells
@TeX{} to equate the next argument with the argument that follows the
equals sign.

@need 1300
For Info, write the following to tell the Info formatters to enclose the
argument between @samp{//} and @samp{\\}:

@example
@group
@@ifinfo
@@definfoenclose phoo, //, \\
@@end ifinfo
@end group
@end example

@noindent
Write the @code{@@definfoenclose} command on a line and follow it with
three arguments separated by commas (commas are used as separators in an
@code{@@node} line in the same way).@refill

@itemize @bullet
@item
The first argument to @code{@@definfoenclose} is the @@-command name
@strong{without} the @samp{@@};

@item
the second argument is the Info start delimiter string; and,

@item
the third argument is the Info end delimiter string.
@end itemize

@noindent
The latter two arguments enclose the highlighted text in the Info file.
A delimiter string may contain spaces.  Neither the start nor end
delimiter is required.  However, if you do not provide a start
delimiter, you must follow the command name with two commas in a row;
otherwise, the Info formatting commands will misinterpret the end
delimiter string as a start delimiter string.@refill

After you have defined @code{@@phoo} both for @TeX{} and for Info, you
can then write @code{@@phoo@{bar@}} to see @samp{//bar\\}
in Info and see
@ifinfo
@samp{bar} in italics in printed output.
@end ifinfo
@iftex
@i{bar} in italics in printed output.
@end iftex

Note that each definition applies to its own formatter: one for @TeX{},
the other for Info.

@need 1200
Here is another example:

@example
@group
@@ifinfo
@@definfoenclose headword, , :
@@end ifinfo
@@iftex
@@global@@let@@headword=@@b
@@end iftex
@end group
@end example

@noindent
This defines @code{@@headword} as an Info formatting command that
inserts nothing before and a colon after the argument and as a @TeX{}
formatting command to typeset its argument in bold.

@node Quotations and Examples, Lists and Tables, Marking Text, Top
@comment  node-name,  next,  previous,  up
@chapter Quotations and Examples

Quotations and examples are blocks of text consisting of one or more
whole paragraphs that are set off from the bulk of the text and
treated differently.  They are usually indented.@refill

In Texinfo, you always begin a quotation or example by writing an
@@-command at the beginning of a line by itself, and end it by writing
an @code{@@end} command that is also at the beginning of a line by
itself.  For instance, you begin an example by writing @code{@@example}
by itself at the beginning of a line and end the example by writing
@code{@@end example} on a line by itself, at the beginning of that
line.@refill
@findex end

@menu
* Block Enclosing Commands::    Use different constructs for
                                  different purposes.
* quotation::                   How to write a quotation.
* example::                     How to write an example in a fixed-width font.
* noindent::                    How to prevent paragraph indentation.
* Lisp Example::                How to illustrate Lisp code.
* smallexample & smalllisp::    Forms for the @code{@@smallbook} option.
* display::                     How to write an example in the current font.
* format::                      How to write an example that does not narrow
                                  the margins.
* exdent::                      How to undo the indentation of a line.
* flushleft & flushright::      How to push text flushleft or flushright.
* cartouche::                   How to draw cartouches around examples.
@end menu

@node Block Enclosing Commands, quotation, Quotations and Examples, Quotations and Examples
@section The Block Enclosing Commands

Here are commands for quotations and examples:@refill

@table @code
@item @@quotation
Indicate text that is quoted. The text is filled, indented, and
printed in a roman font by default.@refill

@item @@example
Illustrate code, commands, and the like. The text is printed
in a fixed-width font, and indented but not filled.@refill

@item @@lisp
Illustrate Lisp code. The text is printed in a fixed-width font,
and indented but not filled.@refill

@item @@smallexample
Illustrate code, commands, and the like.  Similar to
@code{@@example}, except that in @TeX{} this command typesets text in
a smaller font for the smaller @code{@@smallbook} format than for the
8.5 by 11 inch format.@refill

@item @@smalllisp
Illustrate Lisp code.  Similar to @code{@@lisp}, except that
in @TeX{} this command typesets text in a smaller font for the smaller
@code{@@smallbook} format than for the 8.5 by 11 inch format.@refill

@item @@display
Display illustrative text.  The text is indented but not filled, and
no font is specified (so, by default, the font is roman).@refill

@item @@format
Print illustrative text.  The text is not indented and not filled
and no font is specified (so, by default, the font is roman).@refill
@end table

The @code{@@exdent} command is used within the above constructs to
undo the indentation of a line.

The @code{@@flushleft} and @code{@@flushright} commands are used to line
up the left or right margins of unfilled text.@refill

The @code{@@noindent} command may be used after one of the above
constructs to prevent the following text from being indented as a new
paragraph.@refill

You can use the @code{@@cartouche} command within one of the above
constructs to highlight the example or quotation by drawing a box with
rounded corners around it.  (The @code{@@cartouche} command affects
only the printed manual; it has no effect in the Info file; see
@ref{cartouche, , Drawing Cartouches Around Examples}.)@refill

@node quotation, example, Block Enclosing Commands, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@quotation}
@cindex Quotations
@findex quotation

The text of a quotation is
processed normally except that:@refill

@itemize @bullet
@item
the margins are closer to the center of the page, so the whole of the
quotation is indented;@refill

@item
the first lines of paragraphs are indented no more than other
lines;@refill

@item
in the printed output, interparagraph spacing is reduced.@refill
@end itemize

@quotation
This is an example of text written between an @code{@@quotation}
command and an @code{@@end quotation} command.  An @code{@@quotation}
command is most often used to indicate text that is excerpted from
another (real or hypothetical) printed work.@refill
@end quotation

Write an @code{@@quotation} command as text on a line by itself.  This
line will disappear from the output.  Mark the end of the quotation
with a line beginning with and containing only @code{@@end quotation}.
The @code{@@end quotation} line will likewise disappear from the
output.  Thus, the following,@refill

@example
@@quotation
This is
a foo.
@@end quotation
@end example

@noindent
produces

@quotation
This is a foo.
@end quotation

@node example, noindent, quotation, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@example}
@cindex Examples, formatting them
@cindex Formatting examples
@findex example

The @code{@@example} command is used to indicate an example that is
not part of the running text, such as computer input or output.@refill

@example
@group
This is an example of text written between an
@code{@@example} command
and an @code{@@end example} command.
The text is indented but not filled.
@end group

@group
In the printed manual, the text is typeset in a
fixed-width font, and extra spaces and blank lines are
significant.  In the Info file, an analogous result is
obtained by indenting each line with five spaces.
@end group
@end example

Write an @code{@@example} command at the beginning of a line by itself.
This line will disappear from the output.  Mark the end of the example
with an @code{@@end example} command, also written at the beginning of a
line by itself.  The @code{@@end example} will disappear from the
output.@refill

@need 700
For example,

@example
@@example
mv foo bar
@@end example
@end example

@noindent
produces

@example
mv foo bar
@end example

Since the lines containing @code{@@example} and @code{@@end example}
will disappear, you should put a blank line before the
@code{@@example} and another blank line after the @code{@@end
example}.  (Remember that blank lines between the beginning
@code{@@example} and the ending @code{@@end example} will appear in
the output.)@refill

@quotation
@strong{Caution:} Do not use tabs in the lines of an example (or anywhere
else in Texinfo, for that matter)!  @TeX{} treats tabs as single
spaces, and that is not what they look like.  This is a problem with
@TeX{}.  (If necessary, in Emacs, you can use @kbd{M-x untabify} to
convert tabs in a region to multiple spaces.)@refill
@end quotation

Examples are often, logically speaking, ``in the middle'' of a
paragraph, and the text continues after an example should not be
indented.  The @code{@@noindent} command prevents a piece of text from
being indented as if it were a new paragraph.
@ifinfo
(@xref{noindent}.)
@end ifinfo

(The @code{@@code} command is used for examples of code that are
embedded within sentences, not set off from preceding and following
text.  @xref{code, , @code{@@code}}.)

@node noindent, Lisp Example, example, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@noindent}
@findex noindent

An example or other inclusion can break a paragraph into segments.
Ordinarily, the formatters indent text that follows an example as a new
paragraph.  However, you can prevent this by writing @code{@@noindent}
at the beginning of a line by itself preceding the continuation
text.@refill

@need 1500
For example:

@example
@group
@@example
This is an example
@@end example

@@noindent
This line is not indented.  As you can see, the
beginning of the line is fully flush left with the line
that follows after it.  (This whole example is between
@@code@{@@@@display@} and @@code@{@@@@end display@}.)
@end group
@end example

@noindent
produces

@display
@example
This is an example
@end example
@tex
% Remove extra vskip; this is a kludge to counter the effect of display
\vskip-3.5\baselineskip
@end tex

@noindent
This line is not indented.  As you can see, the
beginning of the line is fully flush left with the line
that follows after it.  (This whole example is between
@code{@@display} and @code{@@end display}.)
@end display

To adjust the number of blank lines properly in the Info file output,
remember that the line containing @code{@@noindent} does not generate a
blank line, and neither does the @code{@@end example} line.@refill

In the Texinfo source file for this manual, each line that says
`produces' is preceded by a line containing @code{@@noindent}.@refill

Do not put braces after an @code{@@noindent} command; they are not
necessary, since @code{@@noindent} is a command used outside of
paragraphs (@pxref{Command Syntax}).@refill

@node Lisp Example, smallexample & smalllisp, noindent, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@lisp}
@cindex Lisp example
@findex lisp

The @code{@@lisp} command is used for Lisp code.  It is synonymous
with the @code{@@example} command.

@lisp
This is an example of text written between an
@code{@@lisp} command and an @code{@@end lisp} command.
@end lisp

Use @code{@@lisp} instead of @code{@@example} so as to preserve
information regarding the nature of the example.  This is useful, for
example, if you write a function that evaluates only and all the Lisp
code in a Texinfo file.  Then you can use the Texinfo file as a Lisp
library.@footnote{It would be straightforward to extend Texinfo to
work in a similar fashion for C, @sc{fortran}, or other languages.}@refill

Mark the end of @code{@@lisp} with @code{@@end lisp} on a line by
itself.@refill

@node smallexample & smalllisp, display, Lisp Example, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@smallexample} and @code{@@smalllisp}
@cindex Small book example
@cindex Example for a small book
@cindex Lisp example for a small book
@findex smallexample
@findex smalllisp

In addition to the regular @code{@@example} and @code{@@lisp} commands,
Texinfo has two other ``example-style'' commands.  These are the
@code{@@smallexample} and @code{@@smalllisp} commands.  Both these
commands are designed for use with the @code{@@smallbook} command that
causes @TeX{} to produce a printed manual in a 7 by 9.25 inch format
rather than the regular 8.5 by 11 inch format.@refill

In @TeX{}, the @code{@@smallexample} and @code{@@smalllisp} commands
typeset text in a smaller font for the smaller @code{@@smallbook}
format than for the 8.5 by 11 inch format.  Consequently, many examples
containing long lines fit in a narrower, @code{@@smallbook} page
without needing to be shortened.  Both commands typeset in the normal
font size when you format for the 8.5 by 11 inch size; indeed,
in this situation, the @code{@@smallexample} and @code{@@smalllisp}
commands are defined to be the @code{@@example} and @code{@@lisp}
commands.@refill

In Info, the @code{@@smallexample} and @code{@@smalllisp} commands are
equivalent to the @code{@@example} and @code{@@lisp} commands, and work
exactly the same.@refill

Mark the end of @code{@@smallexample} or @code{@@smalllisp} with
@code{@@end smallexample} or @code{@@end smalllisp},
respectively.@refill

@iftex
Here is an example written in the small font used by the
@code{@@smallexample} and @code{@@smalllisp} commands:

@ifclear smallbook
@display
@tex
% Remove extra vskip; this is a kludge to counter the effect of display
\vskip-3\baselineskip
{\ninett
\dots{} to make sure that you have the freedom to
distribute copies of free software (and charge for
this service if you wish), that you receive source
code or can get it if you want it, that you can
change the software or use pieces of it in new free
programs; and that you know you can do these things.}
@end tex
@end display
@end ifclear
@end iftex
@ifset smallbook
@iftex
@smallexample
This is an example of text written between @code{@@smallexample} and
@code{@@end smallexample}.  In Info and in an 8.5 by 11 inch manual,
this text appears in its normal size; but in a 7 by 9.25 inch manual,
this text appears in a smaller font.
@end smallexample
@end iftex
@end ifset
@ifinfo
@smallexample
This is an example of text written between @code{@@smallexample} and
@code{@@end smallexample}.  In Info and in an 8.5 by 11 inch manual,
this text appears in its normal size; but in a 7 by 9.25 inch manual,
this text appears in a smaller font.
@end smallexample
@end ifinfo

The @code{@@smallexample} and @code{@@smalllisp} commands make it
easier to prepare smaller format manuals without forcing you to edit
examples by hand to fit them onto narrower pages.@refill

As a general rule, a printed document looks better if you write all the
examples in a chapter consistently in @code{@@example} or in
@code{@@smallexample}.  Only occasionally should you mix the two
formats.@refill

@xref{smallbook, , Printing ``Small'' Books}, for more information
about the @code{@@smallbook} command.@refill

@node display, format, smallexample & smalllisp, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@display}
@cindex Display formatting
@findex display

The @code{@@display} command begins a kind of example.  It is like the
@code{@@example} command
except that, in
a printed manual, @code{@@display} does not select the fixed-width
font.  In fact, it does not specify the font at all, so that the text
appears in the same font it would have appeared in without the
@code{@@display} command.@refill

@display
This is an example of text written between an @code{@@display} command
and an @code{@@end display} command.  The @code{@@display} command
indents the text, but does not fill it.
@end display

@node format, exdent, display, Quotations and Examples
@comment  node-name,  next,  previous,  up
@section @code{@@format}
@findex format

The @code{@@format} command is similar to @code{@@example} except
that, in the printed manual, @code{@@format} does not select the
fixed-width font and does not narrow the margins.@refill

@format
This is an example of text written between an @code{@@format} command
and an @code{@@end format} command.  As you can see
from this example,
the @code{@@format} command does not fill the text.
@end format

@node exdent, flushleft & flushright, format, Quotations and Examples
@section @code{@@exdent}: Undoing a Line's Indentation
@cindex Indentation undoing
@findex exdent

The @code{@@exdent} command removes any indentation a line might have.
The command is written at the beginning of a line and applies only to
the text that follows the command that is on the same line.  Do not use
braces around the text.  In a printed manual, the text on an
@code{@@exdent} line is printed in the roman font.@refill

@code{@@exdent} is usually used within examples.  Thus,@refill

@example
@group
@@example
This line follows an @@@@example command.
@@exdent This line is exdented.
This line follows the exdented line.
The @@@@end example comes on the next line.
@@end group
@end group
@end example

@noindent
produces

@example
@group
This line follows an @@example command.
@exdent This line is exdented.
This line follows the exdented line.
The @@end example comes on the next line.
@end group
@end example

In practice, the @code{@@exdent} command is rarely used.
Usually, you un-indent text by ending the example and
returning the page to its normal width.@refill

@node flushleft & flushright, cartouche, exdent, Quotations and Examples
@section @code{@@flushleft} and @code{@@flushright}
@findex flushleft
@findex flushright

The @code{@@flushleft} and @code{@@flushright} commands line up the
ends of lines on the left and right margins of a page,
but do not fill the text.  The commands are written on lines of their
own, without braces.  The @code{@@flushleft} and @code{@@flushright}
commands are ended by @code{@@end flushleft} and @code{@@end
flushright} commands on lines of their own.@refill

@need 1500
For example,

@example
@group
@@flushleft
This text is
written flushleft.
@@end flushleft
@end group
@end example

@noindent
produces

@quotation
@flushleft
This text is
written flushleft.
@end flushleft
@end quotation


Flushright produces the type of indentation often used in the return
address of letters.@refill

@need 1500
@noindent
For example,

@example
@group
@@flushright
Here is an example of text written
flushright.  The @@code@{@@flushright@} command
right justifies every line but leaves the
left end ragged.
@@end flushright
@end group
@end example

@noindent
produces

@flushright
Here is an example of text written
flushright.  The @code{@@flushright} command
right justifies every line but leaves the
left end ragged.
@end flushright

@node cartouche, , flushleft & flushright, Quotations and Examples
@section Drawing Cartouches Around Examples
@findex cartouche
@cindex Box with rounded corners

In a printed manual, the @code{@@cartouche} command draws a box with
rounded corners around its contents.  You can use this command to
further highlight an example or quotation.  For instance, you could
write a manual in which one type of example is surrounded by a cartouche
for emphasis.@refill

The @code{@@cartouche} command affects only the printed manual; it has
no effect in the Info file.@refill

@need 1500
For example,

@example
@group
@@example
@@cartouche
% pwd
/usr/local/lib/emacs/info
@@end cartouche
@@end example
@end group
@end example

@noindent
surrounds the two-line example with a box with rounded corners, in the
printed manual.

@iftex
In a printed manual, the example looks like this:@refill

@example
@group
@cartouche
% pwd
/usr/local/lib/emacs/info
@end cartouche
@end group
@end example
@end iftex

@node Lists and Tables, Indices, Quotations and Examples, Top
@comment  node-name,  next,  previous,  up
@chapter Making Lists and Tables
@cindex Making lists and tables
@cindex Lists and tables, making them
@cindex Tables and lists, making them

Texinfo has several ways of making lists and two-column tables.  Lists can
be bulleted or numbered, while two-column tables can highlight the items in
the first column.@refill

@menu
* Introducing Lists::           Texinfo formats lists for you.
* itemize::                     How to construct a simple list.
* enumerate::                   How to construct a numbered list.
* Two-column Tables::           How to construct a two-column table.
* Multi-column Tables::         How to construct generalized tables.
@end menu

@ifinfo
@node Introducing Lists, itemize, Lists and Tables, Lists and Tables
@heading Introducing Lists
@end ifinfo

Texinfo automatically indents the text in lists or tables, and numbers
an enumerated list.  This last feature is useful if you modify the
list, since you do not need to renumber it yourself.@refill

Numbered lists and tables begin with the appropriate @@-command at the
beginning of a line, and end with the corresponding @code{@@end}
command on a line by itself.  The table and itemized-list commands
also require that you write formatting information on the same line as
the beginning @@-command.@refill

Begin an enumerated list, for example, with an @code{@@enumerate}
command and end the list with an @code{@@end enumerate} command.
Begin an itemized list with an @code{@@itemize} command, followed on
the same line by a formatting command such as @code{@@bullet}, and end
the list with an @code{@@end itemize} command.@refill
@findex end

Precede each element of a list with an @code{@@item} or @code{@@itemx}
command.@refill

@sp 1
@noindent
Here is an itemized list of the different kinds of table and lists:@refill

@itemize @bullet
@item
Itemized lists with and without bullets.

@item
Enumerated lists, using numbers or letters.

@item
Two-column tables with highlighting.
@end itemize

@sp 1
@noindent
Here is an enumerated list with the same items:@refill

@enumerate
@item
Itemized lists with and without bullets.

@item
Enumerated lists, using numbers or letters.

@item
Two-column tables with highlighting.
@end enumerate

@sp 1
@noindent
And here is a two-column table with the same items and their
@w{@@-commands}:@refill

@table @code
@item @@itemize
Itemized lists with and without bullets.

@item @@enumerate
Enumerated lists, using numbers or letters.

@item @@table
@itemx @@ftable
@itemx @@vtable
Two-column tables with indexing.
@end table

@node itemize, enumerate, Introducing Lists, Lists and Tables
@comment  node-name,  next,  previous,  up
@section Making an Itemized List
@cindex Itemization
@findex itemize

The @code{@@itemize} command produces sequences of indented
paragraphs, with a bullet or other mark inside the left margin
at the beginning of each paragraph for which such a mark is desired.@refill

Begin an itemized list by writing @code{@@itemize} at the beginning of
a line.  Follow the command, on the same line, with a character or a
Texinfo command that generates a mark.  Usually, you will write
@code{@@bullet} after @code{@@itemize}, but you can use
@code{@@minus}, or any character or any special symbol that results in
a single character in the Info file.  (When you write @code{@@bullet}
or @code{@@minus} after an @code{@@itemize} command, you may omit the
@samp{@{@}}.)@refill

Write the text of the indented paragraphs themselves after the
@code{@@itemize}, up to another line that says @code{@@end
itemize}.@refill

Before each paragraph for which a mark in the margin is desired, write
a line that says just @code{@@item}.  Do not write any other text on this
line.@refill
@findex item

Usually, you should put a blank line before an @code{@@item}.  This
puts a blank line in the Info file. (@TeX{} inserts the proper
interline whitespace in either case.)  Except when the entries are
very brief, these blank lines make the list look better.@refill

Here is an example of the use of @code{@@itemize}, followed by the
output it produces.  Note that @code{@@bullet} produces an @samp{*} in
Info and a round dot in @TeX{}.@refill

@example
@group
@@itemize @@bullet
@@item
Some text for foo.

@@item
Some text
for bar.
@@end itemize
@end group
@end example

@noindent
This produces:

@quotation
@itemize @bullet
@item
Some text for foo.

@item
Some text
for bar.
@end itemize
@end quotation

Itemized lists may be embedded within other itemized lists.  Here is a
list marked with dashes embedded in a list marked with bullets:@refill

@example
@group
@@itemize @@bullet
@@item
First item.

@@itemize @@minus
@@item
Inner item.

@@item
Second inner item.
@@end itemize

@@item
Second outer item.
@@end itemize
@end group
@end example

@noindent
This produces:

@quotation
@itemize @bullet
@item
First item.

@itemize @minus
@item
Inner item.

@item
Second inner item.
@end itemize

@item
Second outer item.
@end itemize
@end quotation

@node enumerate, Two-column Tables, itemize, Lists and Tables
@comment  node-name,  next,  previous,  up
@section Making a Numbered or Lettered List
@cindex Enumeration
@findex enumerate

@code{@@enumerate} is like @code{@@itemize} except that the marks in
the left margin contain successive integers or letters.
(@xref{itemize, , @code{@@itemize}}.)@refill

Write the @code{@@enumerate} command at the beginning of a line.
The command does not require an argument, but accepts either a number or
a letter as an option.
Without an argument, @code{@@enumerate} starts the list
with the number 1.  With a numeric argument, such as 3,
the command starts the list with that number.
With an upper or lower case letter, such as @kbd{a} or @kbd{A},
the command starts the list with that letter.@refill

Write the text of the enumerated list in the same way you write an
itemized list: put @code{@@item} on a line of its own before the start of
each paragraph that you want enumerated.  Do not write any other text on
the line beginning with @code{@@item}.@refill

You should put a blank line between entries in the list.
This generally makes it easier to read the Info file.@refill

@need 1500
Here is an example of @code{@@enumerate} without an argument:@refill

@example
@group
@@enumerate
@@item
Underlying causes.

@@item
Proximate causes.
@@end enumerate
@end group
@end example

@noindent
This produces:

@enumerate
@item
Underlying causes.

@item
Proximate causes.
@end enumerate
@sp 1
Here is an example with an argument of @kbd{3}:@refill
@sp 1
@example
@group
@@enumerate 3
@@item
Predisposing causes.

@@item
Precipitating causes.

@@item
Perpetuating causes.
@@end enumerate
@end group
@end example

@noindent
This produces:

@enumerate 3
@item
Predisposing causes.

@item
Precipitating causes.

@item
Perpetuating causes.
@end enumerate
@sp 1
Here is a brief summary of the alternatives.  The summary is constructed
using @code{@@enumerate} with an argument of @kbd{a}.@refill
@sp 1
@enumerate a
@item
@code{@@enumerate}

Without an argument, produce a numbered list, starting with the number
1.@refill

@item
@code{@@enumerate @var{positive-integer}}

With a (positive) numeric argument, start a numbered list with that
number.  You can use this to continue a list that you interrupted with
other text.@refill

@item
@code{@@enumerate @var{upper-case-letter}}

With an upper case letter as argument, start a list
in which each item is marked
by a letter, beginning with that upper case letter.@refill

@item
@code{@@enumerate @var{lower-case-letter}}

With a lower case letter as argument, start a list
in which each item is marked by
a letter, beginning with that lower case letter.@refill
@end enumerate

You can also nest enumerated lists, as in an outline.@refill

@node Two-column Tables, Multi-column Tables, enumerate, Lists and Tables
@section Making a Two-column Table
@cindex Tables, making two-column
@findex table

@code{@@table} is similar to @code{@@itemize}, but the command allows
you to specify a name or heading line for each item.  (@xref{itemize,
, @code{@@itemize}}.)  The @code{@@table} command is used to produce
two-column tables, and is especially useful for glossaries and
explanatory exhibits.@refill

@menu
* table::                       How to construct a two-column table.
* ftable vtable::               How to construct a two-column table
                                  with automatic indexing.
* itemx::                       How to put more entries in the first column.
@end menu

@ifinfo
@node table, ftable vtable, Two-column Tables, Two-column Tables
@subheading Using the @code{@@table} Command

Use the @code{@@table} command to produce two-column tables.@refill
@end ifinfo

Write the @code{@@table} command at the beginning of a line and follow
it on the same line with an argument that is a Texinfo command such as
@code{@@code}, @code{@@samp}, @code{@@var}, or @code{@@kbd}.
Although these commands are usually followed by arguments in braces,
in this case you use the command name without an argument because
@code{@@item} will supply the argument.  This command will be applied
to the text that goes into the first column of each item and
determines how it will be highlighted.  For example, @code{@@samp}
will cause the text in the first column to be highlighted with an
@code{@@samp} command.@refill

You may also choose to use the @code{@@asis} command as an argument to
@code{@@table}.  @code{@@asis} is a command that does nothing; if you use this
command after @code{@@table}, @TeX{} and the Info formatting commands
output the first column entries without added highlighting (`as
is').@refill

(The @code{@@table} command may work with other commands besides those
listed here.  However, you can only use commands
that normally take arguments in braces.)@refill

Begin each table entry with an @code{@@item} command at the beginning
of a line.  Write the first column text on the same line as the
@code{@@item} command.  Write the second column text on the line
following the @code{@@item} line and on subsequent lines.  (You do not
need to type anything for an empty second column entry.)  You may
write as many lines of supporting text as you wish, even several
paragraphs.  But only text on the same line as the @code{@@item} will
be placed in the first column.@refill
@findex item

Normally, you should put a blank line before an @code{@@item} line.
This puts a blank like in the Info file.  Except when the entries are
very brief, a blank line looks better.@refill

@need 1500
The following table, for example, highlights the text in the first
column with an @code{@@samp} command:@refill

@example
@group
@@table @@samp
@@item foo
This is the text for
@@samp@{foo@}.

@@item bar
Text for @@samp@{bar@}.
@@end table
@end group
@end example

@noindent
This produces:

@table @samp
@item foo
This is the text for
@samp{foo}.
@item bar
Text for @samp{bar}.
@end table

If you want to list two or more named items with a single block of
text, use the @code{@@itemx} command.  (@xref{itemx, ,
@code{@@itemx}}.)@refill

@node ftable vtable, itemx, table, Two-column Tables
@comment  node-name,  next,  previous,  up
@subsection @code{@@ftable} and @code{@@vtable}
@cindex Tables with indexes
@cindex Indexing table entries automatically
@findex ftable
@findex vtable

The @code{@@ftable} and @code{@@vtable} commands are the same as the
@code{@@table} command except that @code{@@ftable} automatically enters
each of the items in the first column of the table into the index of
functions and @code{@@vtable} automatically enters each of the items in
the first column of the table into the index of variables.  This
simplifies the task of creating indices.  Only the items on the same
line as the @code{@@item} commands are indexed, and they are indexed in
exactly the form that they appear on that line.  @xref{Indices, ,
Creating Indices}, for more information about indices.@refill

Begin a two-column table using @code{@@ftable} or @code{@@vtable} by
writing the @@-command at the beginning of a line, followed on the same
line by an argument that is a Texinfo command such as @code{@@code},
exactly as you would for an @code{@@table} command; and end the table
with an @code{@@end ftable} or @code{@@end vtable} command on a line by
itself.

See the example for @code{@@table} in the previous section.

@node itemx, , ftable vtable, Two-column Tables
@comment  node-name,  next,  previous,  up
@subsection @code{@@itemx}
@cindex Two named items for @code{@@table}
@findex itemx

Use the @code{@@itemx} command inside a table when you have two or
more first column entries for the same item, each of which should
appear on a line of its own.  Use @code{@@itemx} for all but the first
entry.  The @code{@@itemx} command works exactly like @code{@@item}
except that it does not generate extra vertical space above the first
column text.@refill

@need 1000
For example,

@example
@group
@@table @@code
@@item upcase
@@itemx downcase
These two functions accept a character or a string as
argument, and return the corresponding upper case (lower
case) character or string.
@@end table
@end group
@end example

@noindent
This produces:

@table @code
@item upcase
@itemx downcase
These two functions accept a character or a string as
argument, and return the corresponding upper case (lower
case) character or string.@refill
@end table

@noindent
(Note also that this example illustrates multi-line supporting text in
a two-column table.)@refill


@node Multi-column Tables, , Two-column Tables, Lists and Tables
@section Multi-column Tables
@cindex Tables, making multi-column
@findex multitable

@code{@@multitable} allows you to construct tables with any number of
columns, with each column having any width you like.

You define the column widths on the @code{@@multitable} line itself, and
write each row of the actual table following an @code{@@item} command,
with columns separated by an @code{@@tab} command.  Finally, @code{@@end
multitable} completes the table.  Details in the sections below.

@menu
* Multitable Column Widths::    Defining multitable column widths.
* Multitable Rows::             Defining multitable rows, with examples.
@end menu

@node Multitable Column Widths, Multitable Rows, Multi-column Tables, Multi-column Tables
@subsection Multitable Column Widths
@cindex Multitable column widths
@cindex Column widths, defining for multitables
@cindex Widths, defining multitable column

You can define the column widths for a multitable in two ways: as
fractions of the line length; or with a prototype row.  Mixing the two
methods is not supported.  In either case, the widths are defined
entirely on the same line as the @code{@@multitable} command.

@enumerate
@item
@findex columnfractions
@cindex Line length, column widths as fraction of
To specify column widths as fractions of the line length, write
@code{@@columnfractions} and the decimal numbers (presumably less than
1) after the @code{@@multitable} command, as in:

@example
@@multitable @@columnfractions .33 .33 .33
@end example

@noindent The fractions need not add up exactly to 1.0, as these do
not.  This allows you to produce tables that do not need the full line
length.

@item
@cindex Prototype row, column widths defined by
To specify a prototype row, write the longest entry for each column
enclosed in braces after the @code{@@multitable} command.  For example:

@example
@@multitable @{some text for column one@} @{for column two@}
@end example

@noindent
The first column will then have the width of the typeset `some text for
column one', and the second column the width of `for column two'.

The prototype entries need not appear in the table itself.

Although we used simple text in this example, the prototype entries can
contain Texinfo commands; markup commands such as @code{@@code} are
particularly likely to be useful.

@end enumerate


@node Multitable Rows, , Multitable Column Widths, Multi-column Tables
@subsection Multitable Rows
@cindex Multitable rows
@cindex Rows, of a multitable

@findex item
@cindex tab
After the @code{@@multitable} command defining the column widths (see
the previous section), you begin each row in the body of a multitable
with @code{@@item}, and separate the column entries with @code{@@tab}.
Line breaks are not special within the table body, and you may break
input lines in your source file as necessary.

Here is a complete example of a multi-column table (the text is from
the GNU Emacs manual):

@example
@@multitable @@columnfractions .15 .45 .4
@@item Key @@tab Command @@tab Description
@@item C-x 2
@@tab @@code@{split-window-vertically@}
@@tab Split the selected window into two windows,
with one above the other.
@@item C-x 3
@@tab @@code@{split-window-horizontally@}
@@tab Split the selected window into two windows
positioned side by side.
@@item C-Mouse-2
@@tab
@@tab In the mode line or scroll bar of a window,
split that window.
@@end multitable
@end example

@noindent produces:

@multitable @columnfractions .15 .45 .4
@item Key @tab Command @tab Description
@item C-x 2
@tab @code{split-window-vertically}
@tab Split the selected window into two windows,
with one above the other.
@item C-x 3
@tab @code{split-window-horizontally}
@tab Split the selected window into two windows
positioned side by side.
@item C-Mouse-2
@tab
@tab In the mode line or scroll bar of a window,
split that window.
@end multitable


@node Indices, Insertions, Lists and Tables, Top
@comment node-name,  next,  previous,  up
@chapter Creating Indices
@cindex Indices
@cindex Creating indices

Using Texinfo, you can generate indices without having to sort and
collate entries manually.  In an index, the entries are listed in
alphabetical order, together with information on how to find the
discussion of each entry.  In a printed manual, this information
consists of page numbers.  In an Info file, this information is a menu
entry leading to the first node referenced.@refill

Texinfo provides several predefined kinds of index: an index
for functions, an index for variables, an index for concepts, and so
on.  You can combine indices or use them for other than their
canonical purpose.  If you wish, you can define your own indices.@refill

@menu
* Index Entries::               Choose different words for index entries.
* Predefined Indices::          Use different indices for different kinds
                                  of entry.
* Indexing Commands::           How to make an index entry.
* Combining Indices::           How to combine indices.
* New Indices::                 How to define your own indices.
@end menu

@node Index Entries, Predefined Indices, Indices, Indices
@comment  node-name,  next,  previous,  up
@section Making Index Entries
@cindex Index entries, making
@cindex Entries, making index

When you are making index entries, it is good practice to think of the
different ways people may look for something.  Different people
@emph{do not} think of the same words when they look something up.  A
helpful index will have items indexed under all the different words
that people may use.  For example, one reader may think it obvious that
the two-letter names for indices should be listed under ``Indices,
two-letter names'', since the word ``Index'' is the general concept.
But another reader may remember the specific concept of two-letter
names and search for the entry listed as ``Two letter names for
indices''.  A good index will have both entries and will help both
readers.@refill

Like typesetting, the construction of an index is a highly skilled,
professional art, the subtleties of which are not appreciated until you
need to do it yourself.@refill

@xref{Printing Indices & Menus}, for information about printing an index
at the end of a book or creating an index menu in an Info file.@refill

@node Predefined Indices, Indexing Commands, Index Entries, Indices
@comment  node-name,  next,  previous,  up
@section Predefined Indices

Texinfo provides six predefined indices:@refill

@itemize @bullet
@item
A @dfn{concept index} listing concepts that are discussed.@refill

@item
A @dfn{function index} listing functions (such as entry points of
libraries).@refill

@item
A @dfn{variables index} listing variables (such as global variables
of libraries).@refill

@item
A @dfn{keystroke index} listing keyboard commands.@refill

@item
A @dfn{program index} listing names of programs.@refill

@item
A @dfn{data type index} listing data types (such as structures defined in
header files).@refill
@end itemize

@noindent
Not every manual needs all of these, and most manuals use two or three
of them.  This manual has two indices: a
concept index and an @@-command index (that is actually the function
index but is called a command index in the chapter heading).  Two or
more indices can be combined into one using the @code{@@synindex} or
@code{@@syncodeindex} commands.  @xref{Combining Indices}.@refill

@node Indexing Commands, Combining Indices, Predefined Indices, Indices
@comment  node-name,  next,  previous,  up
@section Defining the Entries of an Index
@cindex Defining indexing entries
@cindex Index entries
@cindex Entries for an index
@cindex Specifying index entries
@cindex Creating index entries

The data to make an index come from many individual indexing commands
scattered throughout the Texinfo source file.  Each command says to add
one entry to a particular index; after formatting, the index will give
the current page number or node name as the reference.@refill

An index entry consists of an indexing command at the beginning of a
line followed, on the rest of the line, by the entry.@refill

For example, this section begins with the following five entries for
the concept index:@refill

@example
@@cindex Defining indexing entries
@@cindex Index entries
@@cindex Entries for an index
@@cindex Specifying index entries
@@cindex Creating index entries
@end example

Each predefined index has its own indexing command---@code{@@cindex}
for the concept index, @code{@@findex} for the function index, and so
on.@refill

@cindex Writing index entries
@cindex Index entry writing
Concept index entries consist of text.  The best way to write an index
is to choose entries that are terse yet clear.  If you can do this,
the index often looks better if the entries are not capitalized, but
written just as they would appear in the middle of a sentence.
(Capitalize proper names and acronyms that always call for upper case
letters.)  This is the case convention we use in most GNU manuals'
indices.

If you don't see how to make an entry terse yet clear, make it longer
and clear---not terse and confusing.  If many of the entries are several
words long, the index may look better if you use a different convention:
to capitalize the first word of each entry.  But do not capitalize a
case-sensitive name such as a C or Lisp function name or a shell
command; that would be a spelling error.

Whichever case convention you use, please use it consistently!

@ignore
Concept index entries consist of English text.  The usual convention
is to capitalize the first word of each such index entry, unless that
word is the name of a function, variable, or other such entity that
should not be capitalized.  However, if your concept index entries are
consistently short (one or two words each) it may look better for each
regular entry to start with a lower case letter, aside from proper
names and acronyms that always call for upper case letters.  Whichever
convention you adapt, please be consistent!
@end ignore

Entries in indices other than the concept index are symbol names in
programming languages, or program names; these names are usually
case-sensitive, so use upper and lower case as required for them.

By default, entries for a concept index are printed in a small roman
font and entries for the other indices are printed in a small
@code{@@code} font.  You may change the way part of an entry is
printed with the usual Texinfo commands, such as @code{@@file} for
file names and @code{@@emph} for emphasis (@pxref{Marking
Text}).@refill
@cindex Index font types

@cindex Predefined indexing commands
@cindex Indexing commands, predefined
The six indexing commands for predefined indices are:

@table @code
@item @@cindex @var{concept}
@findex cindex
Make an entry in the concept index for @var{concept}.@refill

@item @@findex @var{function}
@findex findex
Make an entry in the function index for @var{function}.@refill

@item @@vindex @var{variable}
@findex vindex
Make an entry in the variable index for @var{variable}.@refill

@item @@kindex @var{keystroke}
@findex kindex
Make an entry in the key index for @var{keystroke}.@refill

@item @@pindex @var{program}
@findex pindex
Make an entry in the program index for @var{program}.@refill

@item @@tindex @var{data type}
@findex tindex
Make an entry in the data type index for @var{data type}.@refill
@end table

@quotation
@strong{Caution:} Do not use a colon in an index entry.  In Info, a
colon separates the menu entry name from the node name.  An extra
colon confuses Info.
@xref{Menu Parts, , The Parts of a Menu},
for more information about the structure of a menu entry.@refill
@end quotation

If you write several identical index entries in different places in a
Texinfo file, the index in the printed manual will list all the pages to
which those entries refer.  However, the index in the Info file will
list @strong{only} the node that references the @strong{first} of those
index entries.  Therefore, it is best to write indices in which each
entry refers to only one place in the Texinfo file.  Fortunately, this
constraint is a feature rather than a loss since it means that the index
will be easy to use.  Otherwise, you could create an index that lists
several pages for one entry and your reader would not know to which page
to turn.  If you have two identical entries for one topic, change the
topics slightly, or qualify them to indicate the difference.@refill

You are not actually required to use the predefined indices for their
canonical purposes.  For example, suppose you wish to index some C
preprocessor macros.  You could put them in the function index along
with actual functions, just by writing @code{@@findex} commands for
them; then, when you print the ``Function Index'' as an unnumbered
chapter, you could give it the title `Function and Macro Index' and
all will be consistent for the reader.  Or you could put the macros in
with the data types by writing @code{@@tindex} commands for them, and
give that index a suitable title so the reader will understand.
(@xref{Printing Indices & Menus}.)@refill

@node Combining Indices, New Indices, Indexing Commands, Indices
@comment node-name,  next,  previous,  up
@section Combining Indices
@cindex Combining indices
@cindex Indices, combining them

Sometimes you will want to combine two disparate indices such as functions
and concepts, perhaps because you have few enough of one of them that
a separate index for them would look silly.@refill

You could put functions into the concept index by writing
@code{@@cindex} commands for them instead of @code{@@findex} commands,
and produce a consistent manual by printing the concept index with the
title `Function and Concept Index' and not printing the `Function
Index' at all; but this is not a robust procedure.  It works only if
your document is never included as part of another
document that is designed to have a separate function index; if your
document were to be included with such a document, the functions from
your document and those from the other would not end up together.
Also, to make your function names appear in the right font in the
concept index, you would need to enclose every one of them between
the braces of @code{@@code}.@refill

@menu
* syncodeindex::                How to merge two indices, using @code{@@code}
                                  font for the merged-from index.
* synindex::                    How to merge two indices, using the
                                  default font of the merged-to index.
@end menu

@node syncodeindex, synindex, Combining Indices, Combining Indices
@subsection @code{@@syncodeindex}
@findex syncodeindex

When you want to combine functions and concepts into one index, you
should index the functions with @code{@@findex} and index the concepts
with @code{@@cindex}, and use the @code{@@syncodeindex} command to
redirect the function index entries into the concept index.@refill
@findex syncodeindex

The @code{@@syncodeindex} command takes two arguments; they are the name
of the index to redirect, and the name of the index to redirect it to.
The template looks like this:@refill

@example
@@syncodeindex @var{from} @var{to}
@end example

@cindex Predefined names for indices
@cindex Two letter names for indices
@cindex Indices, two letter names
@cindex Names for indices
For this purpose, the indices are given two-letter names:@refill

@table @samp
@item cp
concept index
@item fn
function index
@item vr
variable index
@item ky
key index
@item pg
program index
@item tp
data type index
@end table

Write an @code{@@syncodeindex} command before or shortly after the
end-of-header line at the beginning of a Texinfo file.  For example,
to merge a function index with a concept index, write the
following:@refill

@example
@@syncodeindex fn cp
@end example

@noindent
This will cause all entries designated for the function index to merge
in with the concept index instead.@refill

To merge both a variables index and a function index into a concept
index, write the following:@refill

@example
@group
@@syncodeindex vr cp
@@syncodeindex fn cp
@end group
@end example

@cindex Fonts for indices
The @code{@@syncodeindex} command puts all the entries from the `from'
index (the redirected index) into the @code{@@code} font, overriding
whatever default font is used by the index to which the entries are
now directed.  This way, if you direct function names from a function
index into a concept index, all the function names are printed in the
@code{@@code} font as you would expect.@refill

@node synindex, , syncodeindex, Combining Indices
@subsection @code{@@synindex}
@findex synindex

The @code{@@synindex} command is nearly the same as the
@code{@@syncodeindex} command, except that it does not put the
`from' index  entries into the @code{@@code} font; rather it puts
them in the roman font.  Thus, you use @code{@@synindex} when you
merge a concept index into a function index.@refill

@xref{Printing Indices & Menus}, for information about printing an index
at the end of a book or creating an index menu in an Info file.@refill

@node New Indices, , Combining Indices, Indices
@section Defining New Indices
@cindex Defining new indices
@cindex Indices, defining new
@cindex New index defining
@findex defindex
@findex defcodeindex

In addition to the predefined indices, you may use the
@code{@@defindex} and @code{@@defcodeindex} commands to define new
indices.  These commands create new indexing @@-commands with which
you mark index entries.  The @code{@@defindex }command is used like
this:@refill

@example
@@defindex @var{name}
@end example

The name of an index should be a two letter word, such as @samp{au}.
For example:@refill

@example
@@defindex au
@end example

This defines a new index, called the @samp{au} index.  At the same
time, it creates a new indexing command, @code{@@auindex}, that you
can use to make index entries.  Use the new indexing command just as
you would use a predefined indexing command.@refill

For example, here is a section heading followed by a concept index
entry and two @samp{au} index entries.@refill

@example
@@section Cognitive Semantics
@@cindex kinesthetic image schemas
@@auindex Johnson, Mark
@@auindex Lakoff, George
@end example

@noindent
(Evidently, @samp{au} serves here as an abbreviation for ``author''.)
Texinfo constructs the new indexing command by concatenating the name
of the index with @samp{index}; thus, defining an @samp{au} index
leads to the automatic creation of an @code{@@auindex} command.@refill

Use the @code{@@printindex} command to print the index, as you do with
the predefined indices.  For example:@refill

@example
@group
@@node Author Index, Subject Index, , Top
@@unnumbered Author Index

@@printindex au
@end group
@end example

The @code{@@defcodeindex} is like the @code{@@defindex} command, except
that, in the printed output, it prints entries in an @code{@@code} font
instead of a roman font.  Thus, it parallels the @code{@@findex} command
rather than the @code{@@cindex} command.@refill

You should define new indices within or right after the end-of-header
line of a Texinfo file, before any @code{@@synindex} or
@code{@@syncodeindex} commands (@pxref{Header}).@refill

@node Insertions, Glyphs, Indices, Top
@comment  node-name,  next,  previous,  up
@chapter Special Insertions
@cindex Inserting special characters and symbols
@cindex Special insertions

Texinfo provides several commands for formatting dimensions, for
inserting single characters that have special meaning in Texinfo, such
as braces, and for inserting special graphic symbols that do not
correspond to characters, such as dots and bullets.@refill

@iftex
These are:

@itemize @bullet
@item
Braces, @samp{@@} and periods.

@item
Format a dimension, such as @samp{12@dmn{pt}}.

@item
Dots and bullets.

@item
The @TeX{} logo and the copyright symbol.

@item
A minus sign.
@end itemize
@end iftex

@menu
* Braces Atsigns::              How to insert braces, @samp{@@}.
* Inserting Space::             How to insert the right amount of space
                                  within a sentence.
* Inserting Accents::           How to insert accents and special characters.
* Dots Bullets::                How to insert dots and bullets.
* TeX and copyright::           How to insert the @TeX{} logo
                                  and the copyright symbol.
* pounds::                      How to insert the pounds currency symbol.
* minus::                       How to insert a minus sign.
* math::                        How to format a mathematical expression.
@end menu


@node Braces Atsigns, Inserting Space, Insertions, Insertions
@section Inserting @@ and Braces
@cindex Inserting @@, braces
@cindex Braces, inserting
@cindex Special characters, commands to insert
@cindex Commands to insert special characters

@samp{@@} and curly braces are special characters in Texinfo.  To insert
these characters so they appear in text, you must put an @samp{@@} in
front of these characters to prevent Texinfo from misinterpreting
them.

Do not put braces after any of these commands; they are not
necessary.

@menu
* Inserting An Atsign::         How to insert @samp{@@}.
* Inserting Braces::            How to insert @samp{@{} and @samp{@}}.
@end menu

@node Inserting An Atsign, Inserting Braces, Braces Atsigns, Braces Atsigns
@subsection Inserting @samp{@@} with @@@@
@findex @@ @r{(single @samp{@@})}

@code{@@@@} stands for a single @samp{@@} in either printed or Info
output.

Do not put braces after an @code{@@@@} command.

@node Inserting Braces, , Inserting An Atsign, Braces Atsigns
@subsection Inserting @samp{@{} and @samp{@}}with @@@{ and @@@}
@findex @{ @r{(single @samp{@{})}
@findex @} @r{(single @samp{@}})}

@code{@@@{} stands for a single @samp{@{} in either printed or Info
output.

@code{@@@}} stands for a single @samp{@}} in either printed or Info
output.

Do not put braces after either an @code{@@@{} or an @code{@@@}}
command.


@node Inserting Space, Inserting Accents, Braces Atsigns, Insertions
@section Inserting Space

@cindex Inserting space
@cindex Spacing, inserting
@cindex Whitespace, inserting
The following sections describe commands that control spacing of various
kinds within and after sentences.

@menu
* Not Ending a Sentence::       Sometimes a . doesn't end a sentence.
* Ending a Sentence::           Sometimes it does.
* Multiple Spaces::             Inserting multiple spaces.
* dmn::                         How to format a dimension.
@end menu

@node Not Ending a Sentence, Ending a Sentence, Inserting Space, Inserting Space
@subsection Not Ending a Sentence

@cindex Not ending a sentence
@cindex Sentence non-ending punctuation
@cindex Periods, inserting
Depending on whether a period or exclamation point or question mark is
inside or at the end of a sentence, less or more space is inserted after
a period in a typeset manual.  Since it is not always possible for
Texinfo to determine when a period ends a sentence and when it is used
in an abbreviation, special commands are needed in some circumstances.
(Usually, Texinfo can guess how to handle periods, so you do not need to
use the special commands; you just enter a period as you would if you
were using a typewriter, which means you put two spaces after the
period, question mark, or exclamation mark that ends a sentence.)

@findex : @r{(suppress widening)}
Use the @code{@@:}@: command after a period, question mark,
exclamation mark, or colon that should not be followed by extra space.
For example, use @code{@@:}@: after periods that end abbreviations
which are not at the ends of sentences.  @code{@@:}@: has no effect on
the Info file output.

@need 700
For example,

@example
The s.o.p.@@: has three parts @dots{}
The s.o.p. has three parts @dots{}
@end example

@noindent
@ifinfo
produces
@end ifinfo
@iftex
produces the following.  If you look carefully at this printed output,
you will see a little more whitespace after @samp{s.o.p.} in the second
line.@refill
@end iftex

@quotation
The s.o.p.@: has three parts @dots{}@*
The s.o.p. has three parts @dots{}
@end quotation

@noindent
@kbd{@@:} has no effect on the Info output.  (@samp{s.o.p.} is an
abbreviation for ``Standard Operating Procedure''.)

Do not put braces after @code{@@:}.


@node Ending a Sentence, Multiple Spaces, Not Ending a Sentence, Inserting Space
@subsection Ending a Sentence

@cindex Ending a Sentence
@cindex Sentence ending punctuation

@findex .  @r{(end of sentence)}
@findex ! @r{(end of sentence)}
@findex ? @r{(end of sentence)}
Use @code{@@.}@: instead of a period, @code{@@!}@: instead of an
exclamation point, and @code{@@?}@: instead of a question mark at the end
of a sentence that ends with a single capital letter.  Otherwise, @TeX{}
will think the letter is an abbreviation and will not insert the correct
end-of-sentence spacing.  Here is an example:

@example
Give it to M.I.B. and to M.E.W@@.  Also, give it to R.J.C@@.
Give it to M.I.B. and to M.E.W.  Also, give it to R.J.C.
@end example

@noindent
@ifinfo
produces
@end ifinfo
@iftex
produces the following.  If you look carefully at this printed output,
you will see a little more whitespace after the @samp{W} in the first
line.
@end iftex

@quotation
Give it to M.I.B. and to M.E.W@.  Also, give it to R.J.C@.@*
Give it to M.I.B. and to M.E.W.  Also, give it to R.J.C.
@end quotation

In the Info file output, @code{@@.}@: is equivalent to a simple
@samp{.}; likewise for @code{@@!}@: and @code{@@?}@:.

The meanings of @code{@@:} and @code{@@.}@: in Texinfo are designed to
work well with the Emacs sentence motion commands (@pxref{Sentences,,,
emacs, GNU Emacs}).  This made it necessary for them to be incompatible
with some other formatting systems that use @@-commands.

Do not put braces after any of these commands.


@node Multiple Spaces, dmn, Ending a Sentence, Inserting Space
@subsection Multiple Spaces

@cindex Multiple spaces
@cindex Whitespace, inserting
@findex (space)
@findex (tab)
@findex (newline)

Ordinarily, @TeX{} collapses multiple whitespace characters (space, tab,
and newline) into a single space.  (Info output, on the other hand,
preserves whitespace as you type it, except for changing a newline into
a space; this is why it is important to put two spaces at the end of
sentences in Texinfo documents.)

Occasionally, you may want to actually insert several consecutive
spaces, either for purposes of example (what your program does with
multiple spaces as input), or merely for purposes of appearance in
headings or lists.  Texinfo supports three commands: @code{@@ },
@code{@@@kbd{TAB}}, and @code{@@@kbd{NL}}, all of which insert a single
space into the output.  (Here, @kbd{TAB} and @kbd{NL} represent the tab
character and end-of-line, i.e., when @samp{@@} is the last character on
a line.)

For example,
@example
Spacey@@ @@ @@ @@
example.
@end example

@noindent produces

@example
Spacey@ @ @ @
example.
@end example

Other possible uses of @code{@@ } have been subsumed by @code{@@multitable}
(@pxref{Multi-column Tables}).

Do not follow any of these commands with braces.


@node dmn, , Multiple Spaces, Inserting Space
@subsection @code{@@dmn}@{@var{dimension}@}: Format a Dimension
@cindex Thin space between number, dimension
@cindex Dimension formatting
@cindex Format a dimension
@findex dmn

At times, you may want to write @samp{12@dmn{pt}} or
@samp{8.5@dmn{in}} with little or no space between the number and the
abbreviation for the dimension.  You can use the @code{@@dmn} command
to do this.  On seeing the command, @TeX{} inserts just enough space
for proper typesetting; the Info formatting commands insert no space
at all, since the Info file does not require it.@refill

To use the @code{@@dmn} command, write the number and then follow it
immediately, with no intervening space, by @code{@@dmn}, and then by
the dimension within braces.@refill

@need 700
@noindent
For example,

@example
A4 paper is 8.27@@dmn@{in@} wide.
@end example

@noindent
produces

@quotation
A4 paper is 8.27@dmn{in} wide.
@end quotation

Not everyone uses this style.  Instead of writing
@w{@samp{8.27@@dmn@{in@}}} in the Texinfo file, you may write
@w{@samp{8.27 in.}} or @w{@samp{8.27 inches}}.  (In these cases, the
formatters may insert a line break between the number and the
dimension.  Also, if you write a period after an abbreviation within a
sentence, you should write @samp{@@:} after the period to prevent
@TeX{} from inserting extra whitespace.  @xref{Inserting Space}.


@node Inserting Accents, Dots Bullets, Inserting Space, Insertions
@section Inserting Accents

@cindex Inserting accents
@cindex Accents, inserting
@cindex Floating accents, inserting

Here is a table with the commands Texinfo provides for inserting
floating accents.  The commands with non-alphabetic names do not take
braces around their argument (which is taken to be the next character).
(Exception: @code{@@,} @emph{does} take braces around its argument.)
This is so as to make the source as convenient to type and read as
possible, since accented characters are very common in some languages.

@findex "
@cindex Umlaut accent
@findex '
@cindex Acute accent
@findex =
@cindex Macron accent
@findex ^
@cindex Circumflex accent
@findex `
@cindex Grave accent
@findex ~
@cindex Tilde accent
@findex ,
@cindex Cedilla accent
@findex dotaccent
@cindex Dot accent
@findex H
@cindex Hungariam umlaut accent
@findex ringaccent
@cindex Ring accent
@findex tieaccent
@cindex Tie-after accent
@findex u
@cindex Breve accent
@findex ubaraccent
@cindex Underbar accent
@findex udotaccent
@cindex Underdot accent
@findex v
@cindex Check accent
@multitable {@@questiondown@{@}} {Output} {macron/overbar accent}
@item Command               @tab Output         @tab What
@item @t{@@"o}              @tab @"o            @tab umlaut accent
@item @t{@@'o}              @tab @'o            @tab acute accent
@item @t{@@,@{c@}}          @tab @,{c}          @tab cedilla accent
@item @t{@@=o}              @tab @=o            @tab macron/overbar accent
@item @t{@@^o}              @tab @^o            @tab circumflex accent
@item @t{@@`o}              @tab @`o            @tab grave accent
@item @t{@@~o}              @tab @~o            @tab tilde accent
@item @t{@@dotaccent@{o@}}  @tab @dotaccent{o}  @tab overdot accent
@item @t{@@H@{o@}}          @tab @H{o}          @tab long Hungarian umlaut
@item @t{@@ringaccent@{o@}} @tab @ringaccent{o} @tab ring accent
@item @t{@@tieaccent@{oo@}} @tab @tieaccent{oo} @tab tie-after accent
@item @t{@@u@{o@}}          @tab @u{o}          @tab breve accent
@item @t{@@ubaraccent@{o@}} @tab @ubaraccent{o} @tab underbar accent
@item @t{@@udotaccent@{o@}} @tab @udotaccent{o} @tab underdot accent
@item @t{@@v@{o@}}          @tab @v{o}          @tab hacek or check accent
@end multitable

This table lists the Texinfo commands for inserting other characters
commonly used in languages other than English.

@findex questiondown
@cindex @questiondown{}
@findex exclamdown
@cindex @exclamdown{}
@findex aa
@cindex @aa{}
@findex AA
@cindex @AA{}
@findex ae
@cindex @ae{}
@findex AE
@cindex @AE{}
@findex dotless
@cindex @dotless{i}
@cindex @dotless{j}
@cindex Dotless i, j
@findex l
@cindex @l{}
@findex L
@cindex @L{}
@findex o
@cindex @o{}
@findex O
@cindex @O{}
@findex oe
@cindex @oe{}
@findex OE
@cindex @OE{}
@findex ss
@cindex @ss{}
@cindex Es-zet
@cindex Sharp S
@cindex German S
@multitable {@@questiondown@{@}} {oe,OE} {es-zet or sharp S}
@item @t{@@exclamdown@{@}}   @tab @exclamdown{}   @tab upside-down !
@item @t{@@questiondown@{@}} @tab @questiondown{} @tab upside-down ?
@item @t{@@aa@{@},@@AA@{@}}  @tab @aa{},@AA{}     @tab A,a with circle
@item @t{@@ae@{@},@@AE@{@}}  @tab @ae{},@AE{}     @tab ae,AE ligatures
@item @t{@@dotless@{i@}}     @tab @dotless{i}     @tab dotless i
@item @t{@@dotless@{j@}}     @tab @dotless{j}     @tab dotless j
@item @t{@@l@{@},@@L@{@}}    @tab @l{},@L{}       @tab suppressed-L,l
@item @t{@@o@{@},@@O@{@}}    @tab @o{},@O{}       @tab O,o with slash
@item @t{@@oe@{@},@@OE@{@}}  @tab @oe{},@OE{}     @tab OE,oe ligatures
@item @t{@@ss@{@}}           @tab @ss{}           @tab es-zet or sharp S
@end multitable


@node Dots Bullets, TeX and copyright, Inserting Accents, Insertions
@section Inserting Ellipsis, Dots, and Bullets
@cindex Dots, inserting
@cindex Bullets, inserting
@cindex Ellipsis, inserting
@cindex Inserting ellipsis
@cindex Inserting dots
@cindex Special typesetting commands
@cindex Typesetting commands for dots, etc.

An @dfn{ellipsis} (a line of dots) is not typeset as a string of
periods, so a special command is used for ellipsis in Texinfo.  The
@code{@@bullet} command is special, too.  Each of these commands is
followed by a pair of braces, @samp{@{@}}, without any whitespace
between the name of the command and the braces.  (You need to use braces
with these commands because you can use them next to other text; without
the braces, the formatters would be confused.  @xref{Command Syntax, ,
@@-Command Syntax}, for further information.)@refill

@menu
* dots::                        How to insert dots @dots{}
* bullet::                      How to insert a bullet.
@end menu

@node dots, bullet, Dots Bullets, Dots Bullets
@comment  node-name,  next,  previous,  up
@subsection @code{@@dots}@{@}
@findex dots
@cindex Inserting dots
@cindex Dots, inserting

Use the @code{@@dots@{@}} command to generate an ellipsis, which is
three dots in a row, appropriately spaced, like this: `@dots{}'.  Do
not simply write three periods in the input file; that would work for
the Info file output, but would produce the wrong amount of space
between the periods in the printed manual.

Similarly, the @code{@@enddots@{@}} command generates an
end-of-sentence ellipsis (four dots) @enddots{}

@iftex
Here is an ellipsis: @dots{}
Here are three periods in a row: ...

In printed output, the three periods in a row are closer together than
the dots in the ellipsis.
@end iftex

@node bullet, , dots, Dots Bullets
@comment  node-name,  next,  previous,  up
@subsection @code{@@bullet}@{@}
@findex bullet

Use the @code{@@bullet@{@}} command to generate a large round dot, or
the closest possible thing to one.  In Info, an asterisk is used.@refill

Here is a bullet: @bullet{}

When you use @code{@@bullet} in @code{@@itemize}, you do not need to
type the braces, because @code{@@itemize} supplies them.
(@xref{itemize, , @code{@@itemize}}.)@refill

@node TeX and copyright, pounds, Dots Bullets, Insertions
@comment  node-name,  next,  previous,  up
@section Inserting @TeX{} and the Copyright Symbol

The logo `@TeX{}' is typeset in a special fashion and it needs an
@@-command.  The copyright symbol, `@copyright{}', is also special.
Each of these commands is followed by a pair of braces, @samp{@{@}},
without any whitespace between the name of the command and the
braces.@refill

@menu
* tex::                         How to insert the @TeX{} logo.
* copyright symbol::            How to use @code{@@copyright}@{@}.
@end menu

@node tex, copyright symbol, TeX and copyright, TeX and copyright
@comment  node-name,  next,  previous,  up
@subsection @code{@@TeX}@{@}
@findex tex (command)

Use the @code{@@TeX@{@}} command to generate `@TeX{}'.  In a printed
manual, this is a special logo that is different from three ordinary
letters.  In Info, it just looks like @samp{TeX}.  The
@code{@@TeX@{@}} command is unique among Texinfo commands in that the
@kbd{T} and the @kbd{X} are in upper case.@refill

@node copyright symbol, , tex, TeX and copyright
@comment  node-name,  next,  previous,  up
@subsection @code{@@copyright}@{@}
@findex copyright

Use the @code{@@copyright@{@}} command to generate `@copyright{}'.  In
a printed manual, this is a @samp{c} inside a circle, and in Info,
this is @samp{(C)}.@refill

@node pounds, minus, TeX and copyright, Insertions
@section @code{@@pounds}@{@}
@findex pounds

Use the @code{@@pounds@{@}} command to generate `@pounds{}'.  In a
printed manual, this is the symbol for the currency pounds sterling.
In Info, it is a @samp{#}.  Other currency symbols are unfortunately not
available.

@node minus, math, pounds, Insertions
@section @code{@@minus}@{@}: Inserting a Minus Sign
@findex minus

Use the @code{@@minus@{@}} command to generate a minus sign.  In a
fixed-width font, this is a single hyphen, but in a proportional font,
the symbol is the customary length for a minus sign---a little longer
than a hyphen.@refill

You can compare the two forms:

@display
@samp{@minus{}} is a minus sign generated with @samp{@@minus@{@}},

`-' is a hyphen generated with the character @samp{-}.
@end display

@noindent
In the fixed-width font used by Info, @code{@@minus@{@}} is the same
as a hyphen.@refill

You should not use @code{@@minus@{@}} inside @code{@@code} or
@code{@@example} because the width distinction is not made in the
fixed-width font they use.@refill

When you use @code{@@minus} to specify the mark beginning each entry in
an itemized list, you do not need to type the braces
(@pxref{itemize, , @code{@@itemize}}.)@refill

@node math, , minus, Insertions
@comment  node-name,  next,  previous,  up
@section @code{@@math}: Inserting Mathematical Expressions
@findex math
@cindex Mathematical expressions

You can write a short mathematical expression with the @code{@@math}
command.  Write the mathematical expression between braces, like this:

@example
@@math@{(a + b)(a + b) = a^2 + 2ab + b^2@}
@end example

@iftex
@need 1000
@noindent
This produces the following in @TeX{}:

@display
@math{(a + b)(a + b) = a^2 + 2ab + b^2}
@end display

@noindent
and the following in Info:
@end iftex
@ifinfo
@noindent
This produces the following in Info:
@end ifinfo

@example
(a + b)(a + b) = a^2 + 2ab + b^2
@end example

The @code{@@math} command has no effect on the Info output.  Currently,
it has limited effect on typeset output.  However, this may change since
@TeX{} itself is designed for mathematical typesetting and does a
splendid job.

Certainly, for complex mathematical expressions, you could use @TeX{}
directly.  @xref{Using Ordinary TeX Commands, , Using Ordinary @TeX{}
Commands}.  When you use @TeX{} directly, remember to write the
mathematical expression between one or two @samp{$} (dollar-signs) as
appropriate.

@node Glyphs, Breaks, Insertions, Top
@comment  node-name,  next,  previous,  up
@chapter Glyphs for Examples
@cindex Glyphs

In Texinfo, code is often illustrated in examples that are delimited
by @code{@@example} and @code{@@end example}, or by @code{@@lisp} and
@code{@@end lisp}.  In such examples, you can indicate the results of
evaluation or an expansion using @samp{@result{}} or
@samp{@expansion{}}.  Likewise, there are commands to insert glyphs
to indicate
printed output, error messages, equivalence of expressions, and the
location of point.@refill

The glyph-insertion commands do not need to be used within an example, but
most often they are.  Every  glyph-insertion command is followed by a pair of
left- and right-hand braces.@refill

@menu
* Glyphs Summary::              
* result::                      How to show the result of expression.
* expansion::                   How to indicate an expansion.
* Print Glyph::                 How to indicate printed output.
* Error Glyph::                 How to indicate an error message.
* Equivalence::                 How to indicate equivalence.
* Point Glyph::                 How to indicate the location of point.
@end menu

@node Glyphs Summary, result, Glyphs, Glyphs
@ifinfo
@heading Glyphs Summary

Here are the different glyph commands:@refill
@end ifinfo

@table @asis
@item @result{}
@code{@@result@{@}} points to the result of an expression.@refill

@item @expansion{}
@code{@@expansion@{@}} shows the results of a macro expansion.@refill

@item @print{}
@code{@@print@{@}} indicates printed output.@refill

@item @error{}
@code{@@error@{@}} indicates that the following text is an error
message.@refill

@item @equiv{}
@code{@@equiv@{@}} indicates the exact equivalence of two forms.@refill

@item @point{}
@code{@@point@{@}} shows the location of point.@refill
@end table

@node result, expansion, Glyphs Summary, Glyphs
@section @result{}: Indicating Evaluation
@cindex Result of an expression
@cindex Indicating evaluation
@cindex Evaluation glyph
@cindex Value of an expression, indicating

Use the @code{@@result@{@}} command to indicate the result of
evaluating an expression.@refill

@iftex
The @code{@@result@{@}} command is displayed as @samp{=>} in Info and
as @samp{@result{}} in the printed output.
@end iftex
@ifinfo
The @code{@@result@{@}} command is displayed as @samp{@result{}} in Info
and as a double stemmed arrow in the printed output.@refill
@end ifinfo

Thus, the following,

@lisp
(cdr '(1 2 3))
     @result{} (2 3)
@end lisp

@noindent
may be read as ``@code{(cdr '(1 2 3))} evaluates to @code{(2 3)}''.

@node expansion, Print Glyph, result, Glyphs
@section @expansion{}: Indicating an Expansion
@cindex Expansion, indicating it

When an expression is a macro call, it expands into a new expression.
You can indicate the result of the expansion with the
@code{@@expansion@{@}} command.@refill

@iftex
The @code{@@expansion@{@}} command is displayed as @samp{==>} in Info and
as @samp{@expansion{}} in the printed output.
@end iftex
@ifinfo
The @code{@@expansion@{@}} command is displayed as @samp{@expansion{}}
in Info and as a long arrow with a flat base in the printed output.@refill
@end ifinfo

@need 700
For example, the following

@example
@group
@@lisp
(third '(a b c))
     @@expansion@{@} (car (cdr (cdr '(a b c))))
     @@result@{@} c
@@end lisp
@end group
@end example

@noindent
produces

@lisp
@group
(third '(a b c))
     @expansion{} (car (cdr (cdr '(a b c))))
     @result{} c
@end group
@end lisp

@noindent
which may be read as:

@quotation
@code{(third '(a b c))} expands to @code{(car (cdr (cdr '(a b c))))};
the result of evaluating the expression is @code{c}.
@end quotation

@noindent
Often, as in this case, an example looks better if the
@code{@@expansion@{@}} and @code{@@result@{@}} commands are indented
five spaces.@refill

@node Print Glyph, Error Glyph, expansion, Glyphs
@section @print{}: Indicating Printed Output
@cindex Printed output, indicating it

Sometimes an expression will print output during its execution.  You
can indicate the printed output with the @code{@@print@{@}} command.@refill

@iftex
The @code{@@print@{@}} command is displayed as @samp{-|} in Info and
as @samp{@print{}} in the printed output.
@end iftex
@ifinfo
The @code{@@print@{@}} command is displayed as @samp{@print{}} in Info
and similarly, as a horizontal dash butting against a vertical bar, in
the printed output.@refill
@end ifinfo

In the following example, the printed text is indicated with
@samp{@print{}}, and the value of the expression follows on the
last line.@refill

@lisp
@group
(progn (print 'foo) (print 'bar))
     @print{} foo
     @print{} bar
     @result{} bar
@end group
@end lisp

@noindent
In a Texinfo source file, this example is written as follows:

@lisp
@group
@@lisp
(progn (print 'foo) (print 'bar))
     @@print@{@} foo
     @@print@{@} bar
     @@result@{@} bar
@@end lisp
@end group
@end lisp

@node Error Glyph, Equivalence, Print Glyph, Glyphs
@section @error{}: Indicating an Error Message
@cindex Error message, indicating it

A piece of code may cause an error when you evaluate it.  You can
designate the error message with the @code{@@error@{@}} command.@refill

@iftex
The @code{@@error@{@}} command is displayed as @samp{error-->} in Info
and as @samp{@error{}} in the printed output.
@end iftex
@ifinfo
The @code{@@error@{@}} command is displayed as @samp{@error{}} in Info
and as the word `error' in a box in the printed output.@refill
@end ifinfo

@need 700
Thus,

@example
@@lisp
(+ 23 'x)
@@error@{@} Wrong type argument: integer-or-marker-p, x
@@end lisp
@end example

@noindent
produces

@lisp
(+ 23 'x)
@error{} Wrong type argument: integer-or-marker-p, x
@end lisp

@noindent
This indicates that the following error message is printed
when you evaluate the expression:

@lisp
Wrong type argument: integer-or-marker-p, x
@end lisp

Note that @samp{@error{}} itself is not part of the error
message.

@node Equivalence, Point Glyph, Error Glyph, Glyphs
@section @equiv{}: Indicating Equivalence
@cindex Equivalence, indicating it

Sometimes two expressions produce identical results.  You can indicate the
exact equivalence of two forms with the @code{@@equiv@{@}} command.@refill

@iftex
The @code{@@equiv@{@}} command is displayed as @samp{==} in Info and
as @samp{@equiv{}} in the printed output.
@end iftex
@ifinfo
The @code{@@equiv@{@}} command is displayed as @samp{@equiv{}} in Info
and as a three parallel horizontal lines in the printed output.@refill
@end ifinfo

Thus,

@example
@@lisp
(make-sparse-keymap) @@equiv@{@} (list 'keymap)
@@end lisp
@end example

@noindent
produces

@lisp
(make-sparse-keymap) @equiv{} (list 'keymap)
@end lisp

@noindent
This indicates that evaluating @code{(make-sparse-keymap)} produces
identical results to evaluating @code{(list 'keymap)}.

@c Cannot write point command here because it causes trouble with TOC.
@node Point Glyph, , Equivalence, Glyphs
@section Indicating Point in a Buffer
@cindex Point, indicating it in a buffer

Sometimes you need to show an example of text in an Emacs buffer.  In
such examples, the convention is to include the entire contents of the
buffer in question between two lines of dashes containing the buffer
name.@refill

You can use the @samp{@@point@{@}} command to show the location of point
in the text in the buffer.  (The symbol for point, of course, is not
part of the text in the buffer; it indicates the place @emph{between}
two characters where point is located.)@refill

@iftex
The @code{@@point@{@}} command is displayed as @samp{-!-} in Info and
as @samp{@point{}} in the printed output.
@end iftex
@ifinfo
The @code{@@point@{@}} command is displayed as @samp{@point{}} in Info
and as a small five pointed star in the printed output.@refill
@end ifinfo

The following example shows the contents of buffer @file{foo} before
and after evaluating a Lisp command to insert the word @code{changed}.@refill

@example
@group
---------- Buffer: foo ----------
This is the @point{}contents of foo.
---------- Buffer: foo ----------

@end group
@end example

@example
@group
(insert "changed ")
     @result{} nil
---------- Buffer: foo ----------
This is the changed @point{}contents of foo.
---------- Buffer: foo ----------

@end group
@end example

In a Texinfo source file, the example is written like this:@refill

@example
@@example
---------- Buffer: foo ----------
This is the @@point@{@}contents of foo.
---------- Buffer: foo ----------

(insert "changed ")
     @@result@{@} nil
---------- Buffer: foo ----------
This is the changed @@point@{@}contents of foo.
---------- Buffer: foo ----------
@@end example
@end example

@node Breaks, Definition Commands, Glyphs, Top
@comment  node-name,  next,  previous,  up
@chapter Making and Preventing Breaks
@cindex Making line and page breaks
@cindex Preventing line and page breaks

Usually, a Texinfo file is processed both by @TeX{} and by one of the
Info formatting commands.  Line, paragraph, or page breaks sometimes
occur in the `wrong' place in one or other form of output.  You must
ensure that text looks right both in the printed manual and in the
Info file.@refill

For example, in a printed manual, page breaks may occur awkwardly in
the middle of an example; to prevent this, you can hold text together
using a grouping command that keeps the text from being split across
two pages.  Conversely, you may want to force a page break where none
would occur normally.  Fortunately, problems like these do not often
arise.  When they do, use the break, break prevention, or pagination
commands.@refill

@menu
* Break Commands::              Cause and prevent splits.
* Line Breaks::                 How to force a single line to use two lines.
* - and hyphenation::           How to tell TeX about hyphenation points.
* w::                           How to prevent unwanted line breaks.
* sp::                          How to insert blank lines.
* page::                        How to force the start of a new page.
* group::                       How to prevent unwanted page breaks.
* need::                        Another way to prevent unwanted page breaks.
@end menu

@ifinfo
@node Break Commands, Line Breaks, Breaks, Breaks
@heading The Break Commands
@end ifinfo
@iftex
@sp 1
@end iftex

The break commands create or allow line and paragraph breaks:@refill

@table @code
@item @@*
Force a line break.

@item @@sp @var{n}
Skip @var{n} blank lines.@refill

@item @@-
Insert a discretionary hyphen.

@item @@hyphenation@{@var{hy-phen-a-ted words}@}
Define hyphen points in @var{hy-phen-a-ted words}.
@end table

The line-break-prevention command holds text together all on one
line:@refill

@table @code
@item @@w@{@var{text}@}
Prevent @var{text} from being split and hyphenated across two lines.@refill
@end table
@iftex
@sp 1
@end iftex

The pagination commands apply only to printed output, since Info
files do not have pages.@refill

@table @code
@item @@page
Start a new page in the printed manual.@refill

@item @@group
Hold text together that must appear on one printed page.@refill

@item @@need @var{mils}
Start a new printed page if not enough space on this one.@refill
@end table

@node Line Breaks, - and hyphenation, Break Commands, Breaks
@comment  node-name,  next,  previous,  up
@section @code{@@*}: Generate Line Breaks
@findex * @r{(force line break)}
@cindex Line breaks
@cindex Breaks in a line

The @code{@@*} command forces a line break in both the printed manual and
in Info.@refill

@need 700
For example,

@example
This line @@* is broken @@*in two places.
@end example

@noindent
produces

@example
@group
This line
 is broken
in two places.
@end group
@end example

@noindent
(Note that the space after the first @code{@@*} command is faithfully
carried down to the next line.)@refill

@need 800
The @code{@@*} command is often used in a file's copyright page:@refill

@example
@group
This is edition 2.0 of the Texinfo documentation,@@*
and is for @dots{}
@end group
@end example

@noindent
In this case, the @code{@@*} command keeps @TeX{} from stretching the
line across the whole page in an ugly manner.@refill

@quotation
@strong{Please note:} Do not write braces after an @code{@@*} command;
they are not needed.@refill

Do not write an @code{@@refill} command at the end of a paragraph
containing an @code{@@*} command; it will cause the paragraph to be
refilled after the line break occurs, negating the effect of the line
break.@refill
@end quotation

@node - and hyphenation, w, Line Breaks, Breaks
@section @code{@@-} and @code{@@hyphenation}: Helping @TeX{} hyphenate

@findex -
@findex hyphenation
@cindex Hyphenation, helping @TeX{} do
@cindex Fine-tuning, and hyphenation

Although @TeX{}'s hyphenation algorithm is generally pretty good, it
does miss useful hyphenation points from time to time.  (Or, far more
rarely, insert an incorrect hyphenation.)  So, for documents with an
unusual vocabulary or when fine-tuning for a printed edition, you may
wish to help @TeX{} out.  Texinfo supports two commands for this:

@table @code
@item @@-
Insert a discretionary hyphen, i.e., a place where @TeX{} can (but does
not have to) hyphenate.  This is especially useful when you notice
an overfull hbox is due to @TeX{} missing a hyphenation (@pxref{Overfull
hboxes}).  @TeX{} will not insert any hyphenation points in a word
containing @code{@@-}.

@item @@hyphenation@{@var{hy-phen-a-ted words}@}
Tell @TeX{} how to hyphenate @var{hy-phen-a-ted words}.  As shown, you
put a @samp{-} at each hyphenation point.  For example:
@example
@@hyphenation@{man-u-script man-u-scripts@}
@end example
@noindent @TeX{} only uses the specified hyphenation points when the
words match exactly, so give all necessary variants.
@end table

Info output is not hyphenated, so these commands have no effect there.

@node w, sp, - and hyphenation, Breaks
@comment  node-name,  next,  previous,  up
@section @code{@@w}@{@var{text}@}: Prevent Line Breaks
@findex w @r{(prevent line break)}
@cindex Line breaks, preventing
@cindex Hyphenation, preventing

@code{@@w@{@var{text}@}} outputs @var{text} and prohibits line breaks
within @var{text}.@refill

You can use the @code{@@w} command to prevent @TeX{} from automatically
hyphenating a long name or phrase that accidentally falls near the end
of a line.@refill

@example
You can copy GNU software from @@w@{@@file@{prep.ai.mit.edu@}@}.
@end example

@noindent
produces

@quotation
You can copy GNU software from @w{@file{prep.ai.mit.edu}}.
@end quotation

@quotation
@strong{Caution:} Do not write an @code{@@refill} command at the end
of a paragraph containing an @code{@@w} command; it will cause the
paragraph to be refilled and may thereby negate the effect of the
@code{@@w} command.@refill
@end quotation

@node sp, page, w, Breaks
@comment  node-name,  next,  previous,  up
@section @code{@@sp} @var{n}: Insert Blank Lines
@findex sp @r{(line spacing)}
@cindex Spaces (blank lines)
@cindex Blank lines
@cindex Line spacing

A line beginning with and containing only @code{@@sp @var{n}}
generates @var{n} blank lines of space in both the printed manual and
the Info file.  @code{@@sp} also forces a paragraph break.  For
example,@refill

@example
@@sp 2
@end example

@noindent
generates two blank lines.

The @code{@@sp} command is most often used in the title page.@refill

@ignore
@c node br, page, sp, Breaks
@comment  node-name,  next,  previous,  up
@c section @code{@@br}: Generate Paragraph Breaks
@findex br @r{(paragraph breaks)}
@cindex Paragraph breaks
@cindex Breaks in a paragraph

The @code{@@br} command forces a paragraph break.  It inserts a blank
line.  You can use the command within or at the end of a line.  If
used within a line, the @code{@@br@{@}} command must be followed by
left and right braces (as shown here) to mark the end of the
command.@refill

@need 700
For example,

@example
@group
This line @@br@{@}contains and is ended by paragraph breaks@@br
and is followed by another line.
@end group
@end example

@noindent
produces

@example
@group
This line

contains and is ended by paragraph breaks

and is followed by another line.
@end group
@end example

The @code{@@br} command is seldom used.
@end ignore

@node page, group, sp, Breaks
@comment  node-name,  next,  previous,  up
@section @code{@@page}: Start a New Page
@cindex Page breaks
@findex page

A line containing only @code{@@page} starts a new page in a printed
manual.  The command has no effect on Info files since they are not
paginated.  An @code{@@page} command is often used in the @code{@@titlepage}
section of a Texinfo file to start the copyright page.@refill

@node group, need, page, Breaks
@comment  node-name,  next,  previous,  up
@section @code{@@group}: Prevent Page Breaks
@cindex Group (hold text together vertically)
@cindex Holding text together vertically
@cindex Vertically holding text together
@findex group

The @code{@@group} command (on a line by itself) is used inside an
@code{@@example} or similar construct to begin an unsplittable vertical
group, which will appear entirely on one page in the printed output.
The group is terminated by a line containing only @code{@@end group}.
These two lines produce no output of their own, and in the Info file
output they have no effect at all.@refill

@c Once said that these environments
@c turn off vertical spacing between ``paragraphs''.
@c Also, quotation used to work, but doesn't in texinfo-2.72
Although @code{@@group} would make sense conceptually in a wide
variety of contexts, its current implementation works reliably only
within @code{@@example} and variants, and within @code{@@display},
@code{@@format}, @code{@@flushleft} and @code{@@flushright}.
@xref{Quotations and Examples}.  (What all these commands have in
common is that each line of input produces a line of output.)  In
other contexts, @code{@@group} can cause anomalous vertical
spacing.@refill

@need 750
This formatting requirement means that you should write:

@example
@group
@@example
@@group
@dots{}
@@end group
@@end example
@end group
@end example

@noindent
with the @code{@@group} and @code{@@end group} commands inside the
@code{@@example} and @code{@@end example} commands.

The @code{@@group} command is most often used to hold an example
together on one page.  In this Texinfo manual, more than 100 examples
contain text that is enclosed between @code{@@group} and @code{@@end
group}.

If you forget to end a group, you may get strange and unfathomable
error messages when you run @TeX{}.  This is because @TeX{} keeps
trying to put the rest of the Texinfo file onto the one page and does
not start to generate error messages until it has processed
considerable text.  It is a good rule of thumb to look for a missing
@code{@@end group} if you get incomprehensible error messages in
@TeX{}.@refill

@node need, , group, Breaks
@comment  node-name,  next,  previous,  up
@section @code{@@need @var{mils}}: Prevent Page Breaks
@cindex Need space at page bottom
@findex need

A line containing only @code{@@need @var{n}} starts
a new page in a printed manual if fewer than @var{n} mils (thousandths
of an inch) remain on the current page.  Do not use
braces around the argument @var{n}.  The @code{@@need} command has no
effect on Info files since they are not paginated.@refill

@need 800
This paragraph is preceded by an @code{@@need} command that tells
@TeX{} to start a new page if fewer than 800 mils (eight-tenths
inch) remain on the page.  It looks like this:@refill

@example
@group
@@need 800
This paragraph is preceded by @dots{}
@end group
@end example

The @code{@@need} command is useful for preventing orphans (single
lines at the bottoms of printed pages).@refill

@node Definition Commands, Footnotes, Breaks, Top
@chapter Definition Commands
@cindex Definition commands

The @code{@@deffn} command and the other @dfn{definition commands}
enable you to describe functions, variables, macros, commands, user
options, special forms and other such artifacts in a uniform
format.@refill

In the Info file, a definition causes the entity
category---`Function', `Variable', or whatever---to appear at the
beginning of the first line of the definition, followed by the
entity's name and arguments.  In the printed manual, the command
causes @TeX{} to print the entity's name and its arguments on the left
margin and print the category next to the right margin.  In both
output formats, the body of the definition is indented.  Also, the
name of the entity is entered into the appropriate index:
@code{@@deffn} enters the name into the index of functions,
@code{@@defvr} enters it into the index of variables, and so
on.@refill

A manual need not and should not contain more than one definition for
a given name.  An appendix containing a summary should use
@code{@@table} rather than the definition commands.@refill

@menu
* Def Cmd Template::            How to structure a description using a
                                  definition command.
* Optional Arguments::          How to handle optional and repeated arguments.
* deffnx::                      How to group two or more `first' lines.
* Def Cmds in Detail::          All the definition commands.
* Def Cmd Conventions::         Conventions for writing definitions.
* Sample Function Definition::  
@end menu

@node Def Cmd Template, Optional Arguments, Definition Commands, Definition Commands
@section The Template for a Definition
@cindex Definition template
@cindex Template for a definition

The @code{@@deffn} command is used for definitions of entities that
resemble functions.  To write a definition using the @code{@@deffn}
command, write the @code{@@deffn} command at the beginning of a line
and follow it on the same line by the category of the entity, the name
of the entity itself, and its arguments (if any).  Then write the body
of the definition on succeeding lines.  (You may embed examples in the
body.)  Finally, end the definition with an @code{@@end deffn} command
written on a line of its own.  (The other definition commands follow
the same format.)@refill

The template for a definition looks like this:

@example
@group
@@deffn @var{category} @var{name} @var{arguments}@dots{}
@var{body-of-definition}
@@end deffn
@end group
@end example

@need 700
@noindent
For example,

@example
@group
@@deffn Command forward-word count
This command moves point forward @@var@{count@} words
(or backward if @@var@{count@} is negative). @dots{}
@@end deffn
@end group
@end example

@noindent
produces

@quotation
@deffn Command forward-word count
This function moves point forward @var{count} words
(or backward if @var{count} is negative). @dots{}
@end deffn
@end quotation

Capitalize the category name like a title.  If the name of the
category contains spaces, as in the phrase `Interactive Command',
write braces around it.  For example:@refill

@example
@group
@@deffn @{Interactive Command@} isearch-forward
@dots{}
@@end deffn
@end group
@end example

@noindent
Otherwise, the second word will be mistaken for the name of the
entity.@refill

Some of the definition commands are more general than others.  The
@code{@@deffn} command, for example, is the general definition command
for functions and the like---for entities that may take arguments.  When
you use this command, you specify the category to which the entity
belongs.  The @code{@@deffn} command possesses three predefined,
specialized variations, @code{@@defun}, @code{@@defmac}, and
@code{@@defspec}, that specify the category for you: ``Function'',
``Macro'', and ``Special Form'' respectively.  The @code{@@defvr}
command also is accompanied by several predefined, specialized
variations for describing particular kinds of variables.@refill

The template for a specialized definition, such as @code{@@defun}, is
similar to the template for a generalized definition, except that you
do not need to specify the category:@refill

@example
@group
@@defun @var{name} @var{arguments}@dots{}
@var{body-of-definition}
@@end defun
@end group
@end example

@noindent
Thus,

@example
@group
@@defun buffer-end flag
This function returns @@code@{(point-min)@} if @@var@{flag@}
is less than 1, @@code@{(point-max)@} otherwise.
@dots{}
@@end defun
@end group
@end example

@noindent
produces

@quotation
@defun buffer-end flag
This function returns @code{(point-min)} if @var{flag} is less than 1,
@code{(point-max)} otherwise.  @dots{}
@end defun
@end quotation

@noindent
@xref{Sample Function Definition, Sample Function Definition, A Sample
Function Definition}, for a more detailed example of a function
definition, including the use of @code{@@example} inside the
definition.@refill

The other specialized commands work like @code{@@defun}.@refill

@node Optional Arguments, deffnx, Def Cmd Template, Definition Commands
@section Optional and Repeated Arguments
@cindex Optional and repeated arguments
@cindex Repeated and optional arguments
@cindex Arguments, repeated and optional
@cindex Syntax, optional & repeated arguments
@cindex Meta-syntactic chars for arguments

Some entities take optional or repeated arguments, which may be
specified by a distinctive glyph that uses square brackets and
ellipses.  For @w{example}, a special form often breaks its argument list
into separate arguments in more complicated ways than a
straightforward function.@refill

@iftex
An argument enclosed within square brackets is optional.
Thus, the phrase
@samp{@code{@r{[}@var{optional-arg}@r{]}}} means that
@var{optional-arg} is optional.
An argument followed by an ellipsis is optional
and may be repeated more than once.
@c This is consistent with Emacs Lisp Reference manual
Thus, @samp{@var{repeated-args}@dots{}} stands for zero or more arguments.
Parentheses are used when several arguments are grouped
into additional levels of list structure in Lisp.
@end iftex
@c The following looks better in Info (no `r', `samp' and `code'):
@ifinfo
An argument enclosed within square brackets is optional.
Thus, [@var{optional-arg}] means that @var{optional-arg} is optional.
An argument followed by an ellipsis is optional
and may be repeated more than once.
@c This is consistent with Emacs Lisp Reference manual
Thus, @var{repeated-args}@dots{} stands for zero or more arguments.
Parentheses are used when several arguments are grouped
into additional levels of list structure in Lisp.
@end ifinfo

Here is the @code{@@defspec} line of an example of an imaginary
special form:@refill

@quotation
@defspec foobar (@var{var} [@var{from} @var{to} [@var{inc}]]) @var{body}@dots{}
@end defspec
@tex
\vskip \parskip
@end tex
@end quotation

@noindent
In this example, the arguments @var{from} and @var{to} are optional,
but must both be present or both absent.  If they are present,
@var{inc} may optionally be specified as well.  These arguments are
grouped with the argument @var{var} into a list, to distinguish them
from @var{body}, which includes all remaining elements of the
form.@refill

In a Texinfo source file, this @code{@@defspec} line is written like
this (except it would not be split over two lines, as it is in this
example).@refill

@example
@group
@@defspec foobar (@@var@{var@} [@@var@{from@} @@var@{to@}
     [@@var@{inc@}]]) @@var@{body@}@@dots@{@}
@end group
@end example

@noindent
The function is listed in the Command and Variable Index under
@samp{foobar}.@refill

@node deffnx, Def Cmds in Detail, Optional Arguments, Definition Commands
@section Two or More `First' Lines
@cindex Two `First' Lines for @code{@@deffn}
@cindex Grouping two definitions together
@cindex Definitions grouped together
@findex deffnx

To create two or more `first' or header lines for a definition, follow
the first @code{@@deffn} line by a line beginning with @code{@@deffnx}.
The @code{@@deffnx} command works exactly like @code{@@deffn}
except that it does not generate extra vertical white space between it
and the preceding line.@refill

@need 1000
For example,

@example
@group
@@deffn @{Interactive Command@} isearch-forward
@@deffnx @{Interactive Command@} isearch-backward
These two search commands are similar except @dots{}
@@end deffn
@end group
@end example

@noindent
produces

@deffn {Interactive Command} isearch-forward
@deffnx {Interactive Command} isearch-backward
These two search commands are similar except @dots{}
@end deffn

Each of the other definition commands has an `x' form: @code{@@defunx},
@code{@@defvrx}, @code{@@deftypefunx}, etc.

The `x' forms work just like @code{@@itemx}; see @ref{itemx, , @code{@@itemx}}.

@node Def Cmds in Detail, Def Cmd Conventions, deffnx, Definition Commands
@section The Definition Commands

Texinfo provides more than a dozen definition commands, all of which
are described in this section.@refill

The definition commands automatically enter the name of the entity in
the appropriate index: for example, @code{@@deffn}, @code{@@defun},
and @code{@@defmac} enter function names in the index of functions;
@code{@@defvr} and @code{@@defvar} enter variable names in the index
of variables.@refill

Although the examples that follow mostly illustrate Lisp, the commands
can be used for other programming languages.@refill

@menu
* Functions Commands::          Commands for functions and similar entities.
* Variables Commands::          Commands for variables and similar entities.
* Typed Functions::             Commands for functions in typed languages.
* Typed Variables::             Commands for variables in typed languages.
* Abstract Objects::            Commands for object-oriented programming.
* Data Types::                  The definition command for data types.
@end menu

@node Functions Commands, Variables Commands, Def Cmds in Detail, Def Cmds in Detail
@subsection Functions and Similar Entities

This section describes the commands for describing functions and similar
entities:@refill

@table @code
@findex deffn
@item @@deffn @var{category} @var{name} @var{arguments}@dots{}
The @code{@@deffn} command is the general definition command for
functions, interactive commands, and similar entities that may take
arguments.  You must choose a term to describe the category of entity
being defined; for example, ``Function'' could be used if the entity is
a function.  The @code{@@deffn} command is written at the beginning of a
line and is followed on the same line by the category of entity being
described, the name of this particular entity, and its arguments, if
any.  Terminate the definition with @code{@@end deffn} on a line of its
own.@refill

@need 750
For example, here is a definition:

@example
@group
@@deffn Command forward-char nchars
Move point forward @@var@{nchars@} characters.
@@end deffn
@end group
@end example

@noindent
This shows a rather terse definition for a ``command'' named
@code{forward-char} with one argument, @var{nchars}.

@code{@@deffn} prints argument names such as @var{nchars} in italics or
upper case, as if @code{@@var} had been used, because we think of these
names as metasyntactic variables---they stand for the actual argument
values.  Within the text of the description, write an argument name
explicitly with @code{@@var} to refer to the value of the argument.  In
the example above, we used @samp{@@var@{nchars@}} in this way.

The template for @code{@@deffn} is:

@example
@group
@@deffn @var{category} @var{name} @var{arguments}@dots{}
@var{body-of-definition}
@@end deffn
@end group
@end example

@findex defun
@item @@defun @var{name} @var{arguments}@dots{}
The @code{@@defun} command is the definition command for functions.
@code{@@defun} is equivalent to @samp{@@deffn Function
@dots{}}.@refill

@need 800
@noindent
For example,

@example
@group
@@defun set symbol new-value
Change the value of the symbol @@var@{symbol@}
to @@var@{new-value@}.
@@end defun
@end group
@end example

@noindent
shows a rather terse definition for a function @code{set} whose
arguments are @var{symbol} and @var{new-value}.  The argument names on
the @code{@@defun} line automatically appear in italics or upper case as
if they were enclosed in @code{@@var}.  Terminate the definition with
@code{@@end defun} on a line of its own.@refill

The template is:

@example
@group
@@defun @var{function-name} @var{arguments}@dots{}
@var{body-of-definition}
@@end defun
@end group
@end example

@code{@@defun} creates an entry in the index of functions.

@findex defmac
@item @@defmac @var{name} @var{arguments}@dots{}
The @code{@@defmac} command is the definition command for macros.
@code{@@defmac} is equivalent to @samp{@@deffn Macro @dots{}} and
works like @code{@@defun}.@refill

@findex defspec
@item @@defspec @var{name} @var{arguments}@dots{}
The @code{@@defspec} command is the definition command for special
forms.  (In Lisp, a special form is an entity much like a function.)
@code{@@defspec} is equivalent to @samp{@@deffn @{Special Form@}
@dots{}} and works like @code{@@defun}.@refill
@end table

@node Variables Commands, Typed Functions, Functions Commands, Def Cmds in Detail
@subsection Variables and Similar Entities

Here are the commands for defining variables and similar
entities:@refill

@table @code
@findex defvr
@item @@defvr @var{category} @var{name}
The @code{@@defvr} command is a general definition command for
something like a variable---an entity that records a value.  You must
choose a term to describe the category of entity being defined; for
example, ``Variable'' could be used if the entity is a variable.
Write the @code{@@defvr} command at the beginning of a line and
followed it on the same line by the category of the entity and the
name of the entity.@refill

Capitalize the category name like a title.  If the name of the
category contains spaces, as in the name `User Option', write braces
around it.  Otherwise, the second word will be mistaken for the name
of the entity, for example:

@example
@group
@@defvr @{User Option@} fill-column
This buffer-local variable specifies
the maximum width of filled lines.
@dots{}
@@end defvr
@end group
@end example

Terminate the definition with @code{@@end defvr} on a line of its
own.@refill

The template is:

@example
@group
@@defvr @var{category} @var{name}
@var{body-of-definition}
@@end defvr
@end group
@end example

@code{@@defvr} creates an entry in the index of variables for @var{name}.

@findex defvar
@item @@defvar @var{name}
The @code{@@defvar} command is the definition command for variables.
@code{@@defvar} is equivalent to @samp{@@defvr Variable
@dots{}}.@refill

@need 750
For example:

@example
@group
@@defvar kill-ring
@dots{}
@@end defvar
@end group
@end example

The template is:

@example
@group
@@defvar @var{name}
@var{body-of-definition}
@@end defvar
@end group
@end example

@code{@@defvar} creates an entry in the index of variables for
@var{name}.@refill

@findex defopt
@item @@defopt @var{name}
The @code{@@defopt} command is the definition command for user
options.  @code{@@defopt} is equivalent to @samp{@@defvr @{User
Option@} @dots{}} and works like @code{@@defvar}.@refill
@end table

@node Typed Functions, Typed Variables, Variables Commands, Def Cmds in Detail
@subsection Functions in Typed Languages

The @code{@@deftypefn} command and its variations are for describing
functions in C or any other language in which you must declare types
of variables and functions.@refill

@table @code
@findex deftypefn
@item @@deftypefn @var{category} @var{data-type} @var{name} @var{arguments}@dots{}
The @code{@@deftypefn} command is the general definition command for
functions and similar entities that may take arguments and that are
typed.  The @code{@@deftypefn} command is written at the beginning of
a line and is followed on the same line by the category of entity
being described, the type of the returned value, the name of this
particular entity, and its arguments, if any.@refill

@need 800
@noindent
For example,

@example
@group
@@deftypefn @{Library Function@} int foobar
   (int @@var@{foo@}, float @@var@{bar@})
@dots{}
@@end deftypefn
@end group
@end example

@need 1000
@noindent
(where the text before the ``@dots{}'', shown above as two lines, would
actually be a single line in a real Texinfo file) produces the following
in Info:

@smallexample
@group
-- Library Function: int foobar (int FOO, float BAR)
@dots{}
@end group
@end smallexample
@iftex

In a printed manual, it produces:

@quotation
@deftypefn {Library Function} int foobar (int @var{foo}, float @var{bar})
@dots{}
@end deftypefn
@end quotation
@end iftex

This means that @code{foobar} is a ``library function'' that returns an
@code{int}, and its arguments are @var{foo} (an @code{int}) and
@var{bar} (a @code{float}).@refill

The argument names that you write in @code{@@deftypefn} are not subject
to an implicit @code{@@var}---since the actual names of the arguments in
@code{@@deftypefn} are typically scattered among data type names and
keywords, Texinfo cannot find them without help.  Instead, you must write
@code{@@var} explicitly around the argument names.  In the example
above, the argument names are @samp{foo} and @samp{bar}.@refill

The template for @code{@@deftypefn} is:@refill

@example
@group
@@deftypefn @var{category} @var{data-type} @var{name} @var{arguments} @dots{}
@var{body-of-description}
@@end deftypefn
@end group
@end example

@noindent
Note that if the @var{category} or @var{data type} is more than one
word then it must be enclosed in braces to make it a single argument.@refill

If you are describing a procedure in a language that has packages,
such as Ada, you might consider using @code{@@deftypefn} in a manner
somewhat contrary to the convention described in the preceding
paragraphs.@refill

@need 800
@noindent
For example:

@example
@group
@@deftypefn stacks private push
        (@@var@{s@}:in out stack;
        @@var@{n@}:in integer)
@dots{}
@@end deftypefn
@end group
@end example

@noindent
(The @code{@@deftypefn} arguments are shown split into three lines, but
would be a single line in a real Texinfo file.)

In this instance, the procedure is classified as belonging to the
package @code{stacks} rather than classified as a `procedure' and its
data type is described as @code{private}.  (The name of the procedure
is @code{push}, and its arguments are @var{s} and @var{n}.)@refill

@code{@@deftypefn} creates an entry in the index of functions for
@var{name}.@refill

@findex deftypefun
@item @@deftypefun @var{data-type} @var{name} @var{arguments}@dots{}
The @code{@@deftypefun} command is the specialized definition command
for functions in typed languages.  The command is equivalent to
@samp{@@deftypefn Function @dots{}}.@refill

@need 800
@noindent
Thus,

@smallexample
@group
@@deftypefun int foobar (int @@var@{foo@}, float @@var@{bar@})
@dots{}
@@end deftypefun
@end group
@end smallexample

@noindent
produces the following in Info:

@example
@group
-- Function: int foobar (int FOO, float BAR)
@dots{}
@end group
@end example
@iftex

@need 800
@noindent
and the following in a printed manual:

@quotation
@deftypefun int foobar (int @var{foo}, float @var{bar})
@dots{}
@end deftypefun
@end quotation
@end iftex

@need 800
The template is:

@example
@group
@@deftypefun @var{type} @var{name} @var{arguments}@dots{}
@var{body-of-description}
@@end deftypefun
@end group
@end example

@code{@@deftypefun} creates an entry in the index of functions for
@var{name}.@refill
@end table

@node Typed Variables, Abstract Objects, Typed Functions, Def Cmds in Detail
@subsection Variables in Typed Languages

Variables in typed languages are handled in a manner similar to
functions in typed languages.  @xref{Typed Functions}.  The general
definition command @code{@@deftypevr} corresponds to
@code{@@deftypefn} and the specialized definition command
@code{@@deftypevar} corresponds to @code{@@deftypefun}.@refill

@table @code
@findex deftypevr
@item @@deftypevr @var{category} @var{data-type} @var{name}
The @code{@@deftypevr} command is the general definition command for
something like a variable in a typed language---an entity that records
a value.  You must choose a term to describe the category of the
entity being defined; for example, ``Variable'' could be used if the
entity is a variable.@refill

The @code{@@deftypevr} command is written at the beginning of a line
and is followed on the same line by the category of the entity
being described, the data type, and the name of this particular
entity.@refill

@need 800
@noindent
For example:

@example
@group
@@deftypevr @{Global Flag@} int enable
@dots{}
@@end deftypevr
@end group
@end example

@noindent
produces the following in Info:

@example
@group
-- Global Flag: int enable
@dots{}
@end group
@end example
@iftex

@noindent
and the following in a printed manual:

@quotation
@deftypevr {Global Flag} int enable
@dots{}
@end deftypevr
@end quotation
@end iftex

@need 800
The template is:

@example
@@deftypevr @var{category} @var{data-type} @var{name}
@var{body-of-description}
@@end deftypevr
@end example

@code{@@deftypevr} creates an entry in the index of variables for
@var{name}.@refill

@findex deftypevar
@item @@deftypevar @var{data-type} @var{name}
The @code{@@deftypevar} command is the specialized definition command
for variables in typed languages.  @code{@@deftypevar} is equivalent
to @samp{@@deftypevr Variable @dots{}}.@refill

@need 800
@noindent
For example:

@example
@group
@@deftypevar int fubar
@dots{}
@@end deftypevar
@end group
@end example

@noindent
produces the following in Info:

@example
@group
-- Variable: int fubar
@dots{}
@end group
@end example
@iftex

@need 800
@noindent
and the following in a printed manual:

@quotation
@deftypevar int fubar
@dots{}
@end deftypevar
@end quotation
@end iftex

@need 800
@noindent
The template is:

@example
@group
@@deftypevar @var{data-type} @var{name}
@var{body-of-description}
@@end deftypevar
@end group
@end example

@code{@@deftypevar} creates an entry in the index of variables for
@var{name}.@refill
@end table

@node Abstract Objects, Data Types, Typed Variables, Def Cmds in Detail
@subsection Object-Oriented Programming

Here are the commands for formatting descriptions about abstract
objects, such as are used in object-oriented programming.  A class is
a defined type of abstract object.  An instance of a class is a
particular object that has the type of the class.  An instance
variable is a variable that belongs to the class but for which each
instance has its own value.@refill

In a definition, if the name of a class is truly a name defined in the
programming system for a class, then you should write an @code{@@code}
around it.  Otherwise, it is printed in the usual text font.@refill

@table @code
@findex defcv
@item @@defcv @var{category} @var{class} @var{name}
The @code{@@defcv} command is the general definition command for
variables associated with classes in object-oriented programming.  The
@code{@@defcv} command is followed by three arguments: the category of
thing being defined, the class to which it belongs, and its
name.  Thus,@refill

@example
@group
@@defcv @{Class Option@} Window border-pattern
@dots{}
@@end defcv
@end group
@end example

@noindent
illustrates how you would write the first line of a definition of the
@code{border-pattern} class option of the class @code{Window}.@refill

The template is

@example
@group
@@defcv @var{category} @var{class} @var{name}
@dots{}
@@end defcv
@end group
@end example

@code{@@defcv} creates an entry in the index of variables.

@findex defivar
@item @@defivar @var{class} @var{name}
The @code{@@defivar} command is the definition command for instance
variables in object-oriented programming.  @code{@@defivar} is
equivalent to @samp{@@defcv @{Instance Variable@} @dots{}}@refill

The template is:

@example
@group
@@defivar @var{class} @var{instance-variable-name}
@var{body-of-definition}
@@end defivar
@end group
@end example

@code{@@defivar} creates an entry in the index of variables.

@findex defop
@item @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{}
The @code{@@defop} command is the general definition command for
entities that may resemble methods in object-oriented programming.
These entities take arguments, as functions do, but are associated
with particular classes of objects.@refill

For example, some systems have constructs called @dfn{wrappers} that
are associated with classes as methods are, but that act more like
macros than like functions.  You could use @code{@@defop Wrapper} to
describe one of these.@refill

Sometimes it is useful to distinguish methods and @dfn{operations}.
You can think of an operation as the specification for a method.
Thus, a window system might specify that all window classes have a
method named @code{expose}; we would say that this window system
defines an @code{expose} operation on windows in general.  Typically,
the operation has a name and also specifies the pattern of arguments;
all methods that implement the operation must accept the same
arguments, since applications that use the operation do so without
knowing which method will implement it.@refill

Often it makes more sense to document operations than methods.  For
example, window application developers need to know about the
@code{expose} operation, but need not be concerned with whether a
given class of windows has its own method to implement this operation.
To describe this operation, you would write:@refill

@example
@@defop Operation windows expose
@end example

The @code{@@defop} command is written at the beginning of a line and
is followed on the same line by the overall name of the category of
operation, the name of the class of the operation, the name of the
operation, and its arguments, if any.@refill

@need 800
@noindent
The template is:

@example
@group
@@defop @var{category} @var{class} @var{name} @var{arguments}@dots{}
@var{body-of-definition}
@@end defop
@end group
@end example

@code{@@defop} creates an entry, such as `@code{expose} on
@code{windows}', in the index of functions.@refill

@findex defmethod
@item @@defmethod @var{class} @var{name} @var{arguments}@dots{}
The @code{@@defmethod} command is the definition command for methods
in object-oriented programming.  A method is a kind of function that
implements an operation for a particular class of objects and its
subclasses.  In the Lisp Machine, methods actually were functions, but
they were usually defined with @code{defmethod}.

@code{@@defmethod} is equivalent to @samp{@@defop Method @dots{}}.
The command is written at the beginning of a line and is followed by
the name of the class of the method, the name of the method, and its
arguments, if any.@refill

@need 800
@noindent
For example,

@example
@group
@@defmethod @code{bar-class} bar-method argument
@dots{}
@@end defmethod
@end group
@end example

@noindent
illustrates the definition for a method called @code{bar-method} of
the class @code{bar-class}.  The method takes an argument.@refill

The template is:

@example
@group
@@defmethod @var{class} @var{method-name} @var{arguments}@dots{}
@var{body-of-definition}
@@end defmethod
@end group
@end example

@code{@@defmethod} creates an entry, such as `@code{bar-method} on
@code{bar-class}', in the index of functions.@refill
@end table

@node Data Types, , Abstract Objects, Def Cmds in Detail
@subsection Data Types

Here is the command for data types:@refill

@table @code
@findex deftp
@item @@deftp @var{category} @var{name} @var{attributes}@dots{}
The @code{@@deftp} command is the generic definition command for data
types.  The command is written at the beginning of a line and is
followed on the same line by the category, by the name of the type
(which is a word like @code{int} or @code{float}), and then by names of
attributes of objects of that type.  Thus, you could use this command
for describing @code{int} or @code{float}, in which case you could use
@code{data type} as the category.  (A data type is a category of
certain objects for purposes of deciding which operations can be
performed on them.)@refill

In Lisp, for example,  @dfn{pair} names a particular data
type, and an object of that type has two slots called the
@sc{car} and the @sc{cdr}.  Here is how you would write the first line
of a definition of @code{pair}.@refill

@example
@group
@@deftp @{Data type@} pair car cdr
@dots{}
@@end deftp
@end group
@end example

@need 950
The template is:

@example
@group
@@deftp @var{category} @var{name-of-type} @var{attributes}@dots{}
@var{body-of-definition}
@@end deftp
@end group
@end example

@code{@@deftp} creates an entry in the index of data types.
@end table

@node Def Cmd Conventions, Sample Function Definition, Def Cmds in Detail, Definition Commands
@section Conventions for Writing Definitions
@cindex Definition conventions
@cindex Conventions for writing definitions

When you write a definition using @code{@@deffn}, @code{@@defun}, or
one of the other definition commands, please take care to use
arguments that indicate the meaning, as with the @var{count} argument
to the @code{forward-word} function.  Also, if the name of an argument
contains the name of a type, such as @var{integer}, take care that the
argument actually is of that type.@refill

@node Sample Function Definition, , Def Cmd Conventions, Definition Commands
@section A Sample Function Definition
@cindex Function definitions
@cindex Command definitions
@cindex Macro definitions
@cindex Sample function definition

A function definition uses the @code{@@defun} and @code{@@end defun}
commands.  The name of the function follows immediately after the
@code{@@defun} command and it is followed, on the same line, by the
parameter list.@refill

Here is a definition from @cite{The GNU Emacs Lisp Reference Manual}.
(@xref{Calling Functions, , Calling Functions, elisp, The GNU Emacs
Lisp Reference Manual}.)

@quotation
@defun apply function &rest arguments
@code{apply} calls @var{function} with @var{arguments}, just
like @code{funcall} but with one difference: the last of
@var{arguments} is a list of arguments to give to
@var{function}, rather than a single argument.  We also say
that this list is @dfn{appended} to the other arguments.

@code{apply} returns the result of calling @var{function}.
As with @code{funcall}, @var{function} must either be a Lisp
function or a primitive function; special forms and macros
do not make sense in @code{apply}.

@example
(setq f 'list)
     @result{} list
(apply f 'x 'y 'z)
@error{} Wrong type argument: listp, z
(apply '+ 1 2 '(3 4))
     @result{} 10
(apply '+ '(1 2 3 4))
     @result{} 10

(apply 'append '((a b c) nil (x y z) nil))
     @result{} (a b c x y z)
@end example

An interesting example of using @code{apply} is found in the description
of @code{mapcar}.@refill
@end defun
@end quotation

@need 1200
In the Texinfo source file, this example looks like this:

@example
@group
@@defun apply function &rest arguments

@@code@{apply@} calls @@var@{function@} with
@@var@{arguments@}, just like @@code@{funcall@} but with one
difference: the last of @@var@{arguments@} is a list of
arguments to give to @@var@{function@}, rather than a single
argument.  We also say that this list is @@dfn@{appended@}
to the other arguments.
@end group

@group
@@code@{apply@} returns the result of calling
@@var@{function@}.  As with @@code@{funcall@},
@@var@{function@} must either be a Lisp function or a
primitive function; special forms and macros do not make
sense in @@code@{apply@}.
@end group

@group
@@example
(setq f 'list)
     @@result@{@} list
(apply f 'x 'y 'z)
@@error@{@} Wrong type argument: listp, z
(apply '+ 1 2 '(3 4))
     @@result@{@} 10
(apply '+ '(1 2 3 4))
     @@result@{@} 10

(apply 'append '((a b c) nil (x y z) nil))
     @@result@{@} (a b c x y z)
@@end example
@end group

@group
An interesting example of using @@code@{apply@} is found
in the description of @@code@{mapcar@}.@@refill
@@end defun
@end group
@end example

@noindent
In this manual, this function is listed in the Command and Variable
Index under @code{apply}.@refill

Ordinary variables and user options are described using a format like
that for functions except that variables do not take arguments.

@node Footnotes, Conditionals, Definition Commands, Top
@comment  node-name,  next,  previous,  up
@chapter Footnotes
@cindex Footnotes
@findex footnote

A @dfn{footnote} is for a reference that documents or elucidates the
primary text.@footnote{A footnote should complement or expand upon
the primary text, but a reader should not need to read a footnote to
understand the primary text.  For a thorough discussion of footnotes,
see @cite{The Chicago Manual of Style}, which is published by the
University of Chicago Press.}@refill

@menu
* Footnote Commands::           How to write a footnote in Texinfo.
* Footnote Styles::             Controlling how footnotes appear in Info.
@end menu

@node Footnote Commands, Footnote Styles, Footnotes, Footnotes
@section Footnote Commands

In Texinfo, footnotes are created with the @code{@@footnote} command.
This command is followed immediately by a left brace, then by the text
of the footnote, and then by a terminating right brace.  The template
is:

@example
@@footnote@{@var{text}@}
@end example

Footnotes may be of any length, but are usually short.@refill

For example, this clause is followed by a sample
footnote@footnote{Here is the sample footnote.}; in the Texinfo
source, it looks like this:@refill

@example
@dots{}a sample footnote @@footnote@{Here is the sample
footnote.@}; in the Texinfo source@dots{}
@end example

@strong{Warning:} Don't use footnotes in the argument of the
@code{@@item} command for a @code{@@table} table.  This doesn't work;
because of limitations of @TeX{}, there is no way to fix it.  To avoid
the problem, move the footnote into the body text of the table.

In a printed manual or book, the reference mark for a footnote is a
small, superscripted number; the text of the footnote appears at the
bottom of the page, below a horizontal line.@refill

In Info, the reference mark for a footnote is a pair of parentheses
with the footnote number between them, like this: @samp{(1)}.@refill

@node Footnote Styles, , Footnote Commands, Footnotes
@section Footnote Styles

Info has two footnote styles, which determine where the text of the
footnote is located:@refill

@itemize @bullet
@cindex @samp{@r{End}} node footnote style
@item
In the `End' node style, all the footnotes for a single node
are placed at the end of that node.  The footnotes are separated from
the rest of the node by a line of dashes with the word
@samp{Footnotes} within it.  Each footnote begins with an
@samp{(@var{n})} reference mark.@refill

@need 700
@noindent
Here is an example of a single footnote in the end of node style:@refill

@example
@group
 --------- Footnotes ---------

(1)  Here is a sample footnote.
@end group
@end example

@cindex @samp{@r{Separate}} footnote style
@item
In the `Separate' node style, all the footnotes for a single
node are placed in an automatically constructed node of
their own.  In this style, a ``footnote reference'' follows
each @samp{(@var{n})} reference mark in the body of the
node.  The footnote reference is actually a cross reference
which you use to reach the footnote node.@refill

The name of the node containing the footnotes is constructed
by appending @w{@samp{-Footnotes}} to the name of the node
that contains the footnotes. (Consequently, the footnotes'
node for the @file{Footnotes} node is
@w{@file{Footnotes-Footnotes}}!)  The footnotes' node has an
`Up' node pointer that leads back to its parent node.@refill

@noindent
Here is how the first footnote in this manual looks after being
formatted for Info in the separate node style:@refill

@smallexample
@group
File: texinfo.info  Node: Overview-Footnotes, Up: Overview

(1) Note that the first syllable of "Texinfo" is
pronounced like "speck", not "hex". @dots{}
@end group
@end smallexample
@end itemize

A Texinfo file may be formatted into an Info file with either footnote
style.@refill

@findex footnotestyle
Use the @code{@@footnotestyle} command to specify an Info file's
footnote style.  Write this command at the beginning of a line followed
by an argument, either @samp{end} for the end node style or
@samp{separate} for the separate node style.

@need 700
For example,

@example
@@footnotestyle end
@end example
@noindent
or
@example
@@footnotestyle separate
@end example

Write an @code{@@footnotestyle} command before or shortly after the
end-of-header line at the beginning of a Texinfo file.  (If you
include the @code{@@footnotestyle} command between the start-of-header
and end-of-header lines, the region formatting commands will format
footnotes as specified.)@refill

If you do not specify a footnote style, the formatting commands use
their default style.  Currently, @code{texinfo-format-buffer} and
@code{texinfo-format-region} use the `separate' style and
@code{makeinfo} uses the `end' style.@refill

@c !!! note: makeinfo's --footnote-style option overrides footnotestyle
@ignore
If you use @code{makeinfo} to create the Info file, the
@samp{--footnote-style} option determines which style is used,
@samp{end} for the end of node style or @samp{separate} for the
separate node style.  Thus, to format the Texinfo manual in the
separate node style, you would use the following shell command:@refill

@example
makeinfo --footnote-style=separate texinfo.texi
@end example

@noindent
To format the Texinfo manual in the end of node style, you would
type:@refill

@example
makeinfo --footnote-style=end texinfo.texi
@end example
@end ignore
@ignore
If you use @code{texinfo-format-buffer} or
@code{texinfo-format-region} to create the Info file, the value of the
@code{texinfo-footnote-style} variable controls the footnote style.
It can be either @samp{"separate"} for the separate node style or
@samp{"end"} for the end of node style.  (You can change the value of
this variable with the @kbd{M-x edit-options} command (@pxref{Edit
Options, , Editing Variable Values, emacs, The GNU Emacs Manual}), or
with the @kbd{M-x set-variable} command (@pxref{Examining, , Examining
and Setting Variables, emacs, The GNU Emacs Manual}).@refill

The @code{texinfo-footnote-style} variable also controls the style if
you use the @kbd{M-x makeinfo-region} or @kbd{M-x makeinfo-buffer}
command in Emacs.@refill
@end ignore
This chapter contains two footnotes.@refill

@node Conditionals, Macros, Footnotes, Top
@comment  node-name,  next,  previous,  up
@chapter Conditionally Visible Text
@cindex Conditionally visible text
@cindex Text, conditionally visible
@cindex Visibility of conditional text
@cindex If text conditionally visible
@findex ifhtml
@findex ifinfo
@findex iftex

Sometimes it is good to use different text for a printed manual and
its corresponding Info file.  In this case, you can use the
@dfn{conditional commands} to specify which text is for the printed manual
and which is for the Info file.@refill

@menu
* Conditional Commands::        How to specify text for HTML, Info, or @TeX{}.
* Using Ordinary TeX Commands::  You can use any and all @TeX{} commands.
* set clear value::             How to designate which text to format (for
                                  both Info and @TeX{}); and how to set a
                                  flag to a string that you can insert.
@end menu

@node Conditional Commands, Using Ordinary TeX Commands, Conditionals, Conditionals
@ifinfo
@heading Using @code{@@ifinfo} and @code{@@iftex}
@end ifinfo

@code{@@ifinfo} begins segments of text that should be ignored
by @TeX{} when it
typesets the printed manual.  The segment of text appears only
in the Info file.
The @code{@@ifinfo} command should appear on a line by itself;  end
the Info-only text with a line containing @code{@@end ifinfo} by
itself.  At the beginning of a Texinfo file, the Info permissions are
contained within a region marked by @code{@@ifinfo} and @code{@@end
ifinfo}. (@xref{Info Summary and Permissions}.)@refill

The @code{@@iftex} and @code{@@end iftex} commands are similar to the
@code{@@ifinfo} and @code{@@end ifinfo} commands, except that they
specify text that will appear in the printed manual but not in the Info
file.  Likewise for @code{@@ifhtml} and @code{@@end ifhtml}, which
specify text to appear only in HTML output.@refill

@need 700
For example,

@example
@@iftex
This text will appear only in the printed manual.
@@end iftex

@@ifinfo
However, this text will appear only in Info.
@@end ifinfo
@end example

@noindent
The preceding example produces the following line:

@iftex
This text will appear only in the printed manual.
@end iftex

@ifinfo
However, this text will appear only in Info.
@end ifinfo

@noindent
Note how you only see one of the two lines, depending on whether you
are reading the Info version or the printed version of this
manual.@refill

The @code{@@titlepage} command is a special variant of @code{@@iftex} that
is used for making the title and copyright pages of the printed
manual. (@xref{titlepage, , @code{@@titlepage}}.) @refill

@node Using Ordinary TeX Commands, set clear value, Conditional Commands, Conditionals
@comment  node-name,  next,  previous,  up
@section Using Ordinary @TeX{} Commands
@cindex @TeX{} commands, using ordinary
@cindex Ordinary @TeX{} commands, using
@cindex Commands using ordinary @TeX{}
@cindex plain @TeX{}

Inside a region delineated by @code{@@iftex} and @code{@@end iftex},
you can embed some plain @TeX{} commands.  Info will ignore these
commands since they are only in that part of the file which is seen by
@TeX{}.  You can write the @TeX{} commands as you would write them in
a normal @TeX{} file, except that you must replace the @samp{\} used
by @TeX{} with an @samp{@@}.  For example, in the @code{@@titlepage}
section of a Texinfo file, you can use the @TeX{} command
@code{@@vskip} to format the copyright page.  (The @code{@@titlepage}
command causes Info to ignore the region automatically, as it does
with the @code{@@iftex} command.)@refill

However, many features of plain @TeX{} will not work, as they are
overridden by features of Texinfo.

@findex tex
You can enter plain @TeX{} completely, and use @samp{\} in the @TeX{}
commands, by delineating a region with the @code{@@tex} and @code{@@end
tex} commands.  (The @code{@@tex} command also causes Info to ignore the
region, like the @code{@@iftex}
command.)@refill

@cindex Mathematical expressions
For example, here is a mathematical expression written in
plain @TeX{}:@refill

@example
@@tex
$$ \chi^2 = \sum_@{i=1@}^N
          \left (y_i - (a + b x_i)
          \over \sigma_i\right)^2 $$
@@end tex
@end example

@noindent
The output of this example will appear only in a printed manual.  If
you are reading this in Info, you will not see anything after this
paragraph.
@iftex
In a printed manual, the above expression looks like
this:
@end iftex

@tex
$$ \chi^2 = \sum_{i=1}^N
          \left(y_i - (a + b x_i)
          \over \sigma_i\right)^2 $$
@end tex

@node set clear value, , Using Ordinary TeX Commands, Conditionals
@comment  node-name,  next,  previous,  up
@section @code{@@set}, @code{@@clear}, and @code{@@value}

You can direct the Texinfo formatting commands to format or ignore parts
of a Texinfo file with the @code{@@set}, @code{@@clear}, @code{@@ifset},
and @code{@@ifclear} commands.@refill

In addition, you can use the @code{@@set @var{flag}} command to set the
value of @var{flag} to a string of characters; and use
@code{@@value@{@var{flag}@}} to insert that string.  You can use
@code{@@set}, for example, to set a date and use @code{@@value} to
insert the date in several places in the Texinfo file.@refill

@menu
* ifset ifclear::               Format a region if a flag is set.
* value::                       Replace a flag with a string.
* value Example::               An easy way to update edition information.
@end menu

@node ifset ifclear, value, set clear value, set clear value
@subsection @code{@@ifset} and @code{@@ifclear}

@findex ifset
When a @var{flag} is set, the Texinfo formatting commands format text
between subsequent pairs of @code{@@ifset @var{flag}} and @code{@@end
ifset} commands.  When the @var{flag} is cleared, the Texinfo formatting
commands do @emph{not} format the text.

Use the @code{@@set @var{flag}} command to turn on, or @dfn{set}, a
@var{flag}; a @dfn{flag} can be any single word.  The format for the
command looks like this:@refill
@findex set

@example
@@set @var{flag}
@end example

Write the conditionally formatted text between @code{@@ifset @var{flag}}
and @code{@@end ifset} commands, like this:@refill

@example
@group
@@ifset @var{flag}
@var{conditional-text}
@@end ifset
@end group
@end example

For example, you can create one document that has two variants, such as
a manual for a `large' and `small' model:@refill

@example
You can use this machine to dig up shrubs
without hurting them.

@@set large

@@ifset large
It can also dig up fully grown trees.
@@end ifset

Remember to replant promptly @dots{}
@end example

@noindent
In the example, the formatting commands will format the text between
@code{@@ifset large} and @code{@@end ifset} because the @code{large}
flag is set.@refill

@findex clear
Use the @code{@@clear @var{flag}} command to turn off, or @dfn{clear},
a flag.  Clearing a flag is the opposite of setting a flag.  The
command looks like this:@refill

@example
@@clear @var{flag}
@end example

@noindent
Write the command on a line of its own.

When @var{flag} is cleared, the Texinfo formatting commands do
@emph{not} format the text between @code{@@ifset @var{flag}} and
@code{@@end ifset}; that text is ignored and does not appear in either
printed or Info output.@refill

For example, if you clear the flag of the preceding example by writing
an @code{@@clear large} command after the @code{@@set large} command
(but before the conditional text), then the Texinfo formatting commands
ignore the text between the @code{@@ifset large} and @code{@@end ifset}
commands.  In the formatted output, that text does not appear; in both
printed and Info output, you see only the lines that say, ``You can use
this machine to dig up shrubs without hurting them.  Remember to replant
promptly @dots{}''.

@findex ifclear
If a flag is cleared with an @code{@@clear @var{flag}} command, then
the formatting commands format text between subsequent pairs of
@code{@@ifclear} and @code{@@end ifclear} commands.  But if the flag
is set with @code{@@set @var{flag}}, then the formatting commands do
@emph{not} format text between an @code{@@ifclear} and an @code{@@end
ifclear} command; rather, they ignore that text.  An @code{@@ifclear}
command looks like this:@refill

@example
@@ifclear @var{flag}
@end example

@need 700
In brief, the commands are:@refill

@table @code
@item @@set @var{flag}
Tell the Texinfo formatting commands that @var{flag} is set.@refill

@item @@clear @var{flag}
Tell the Texinfo formatting commands that @var{flag} is cleared.@refill

@item @@ifset @var{flag}
If @var{flag} is set, tell the Texinfo formatting commands to format
the text up to the following @code{@@end ifset} command.@refill

If @var{flag} is cleared, tell the Texinfo formatting commands to
ignore text up to the following @code{@@end ifset} command.@refill

@item @@ifclear @var{flag}
If @var{flag} is set, tell the Texinfo formatting commands to ignore
the text up to the following @code{@@end ifclear} command.@refill

If @var{flag} is cleared, tell the Texinfo formatting commands to
format the text up to the following @code{@@end ifclear}
command.@refill
@end table

@node value, value Example, ifset ifclear, set clear value
@subsection @code{@@value}
@findex value

You can use the @code{@@set} command to specify a value for a flag,
which is expanded by the @code{@@value} command.  The value is a string
a characters.

Write the @code{@@set} command like this:

@example
@@set foo This is a string.
@end example

@noindent
This sets the value of @code{foo} to ``This is a string.''

The Texinfo formatters replace an @code{@@value@{@var{flag}@}} command with
the string to which @var{flag} is set.@refill

Thus, when @code{foo} is set as shown above, the Texinfo formatters convert

@example
@group
@@value@{foo@}
@exdent @r{to}
This is a string.
@end group
@end example

You can write an @code{@@value} command within a paragraph; but you
must write an @code{@@set} command on a line of its own.

If you write the @code{@@set} command like this:

@example
@@set foo
@end example

@noindent
without specifying a string, the value of @code{foo} is an empty string.

If you clear a previously set flag with an @code{@@clear @var{flag}}
command, a subsequent @code{@@value@{flag@}} command is invalid and the
string is replaced with an error message that says @samp{@{No value for
"@var{flag}"@}}.

For example, if you set @code{foo} as follows:@refill

@example
@@set how-much very, very, very
@end example

@noindent
then the formatters transform

@example
@group
It is a @@value@{how-much@} wet day.
@exdent @r{into}
It is a very, very, very wet day.
@end group
@end example

If you write

@example
@@clear how-much
@end example

@noindent
then the formatters transform

@example
@group
It is a @@value@{how-much@} wet day.
@exdent @r{into}
It is a @{No value for "how-much"@} wet day.
@end group
@end example

@node value Example, , value, set clear value
@subsection @code{@@value} Example

You can use the @code{@@value} command to limit the number of places you
need to change when you record an update to a manual.
Here is how it is done in @cite{The GNU Make Manual}:

@need 1000
@noindent
Set the flags:

@example
@group
@@set EDITION 0.35 Beta
@@set VERSION 3.63 Beta
@@set UPDATED 14 August 1992
@@set UPDATE-MONTH August 1992
@end group
@end example

@need 750
@noindent
Write text for the first @code{@@ifinfo} section, for people reading the
Texinfo file:

@example
@group
This is Edition @@value@{EDITION@},
last updated @@value@{UPDATED@},
of @@cite@{The GNU Make Manual@},
for @@code@{make@}, Version @@value@{VERSION@}.
@end group
@end example

@need 1000
@noindent
Write text for the title page, for people reading the printed manual:
@c List only the month and the year since that looks less fussy on a
@c printed cover than a date that lists the day as well.

@example
@group
@@title GNU Make
@@subtitle A Program for Directing Recompilation
@@subtitle Edition @@value@{EDITION@}, @dots{}
@@subtitle @@value@{UPDATE-MONTH@}
@end group
@end example

@noindent
(On a printed cover, a date listing the month and the year looks less
fussy than a date listing the day as well as the month and year.)

@need 750
@noindent
Write text for the Top node, for people reading the Info file:

@example
@group
This is Edition @@value@{EDITION@}
of the @@cite@{GNU Make Manual@},
last updated @@value@{UPDATED@}
for @@code@{make@} Version @@value@{VERSION@}.
@end group
@end example

@need 950
After you format the manual, the text in the first @code{@@ifinfo}
section looks like this:

@example
@group
This is Edition 0.35 Beta, last updated 14 August 1992,
of `The GNU Make Manual', for `make', Version 3.63 Beta.
@end group
@end example

When you update the manual, change only the values of the flags; you do
not need to rewrite the three sections.


@node Macros, Format/Print Hardcopy, Conditionals, Top
@chapter Macros: Defining New Texinfo Commands
@cindex Macros
@cindex Defining new Texinfo commands
@cindex New Texinfo commands, defining
@cindex Texinfo commands, defining new
@cindex User-defined Texinfo commands

A Texinfo @dfn{macro} allows you to define a new Texinfo command as any
sequence of text and/or existing commands (including other macros).  The
macro can have any number of @dfn{parameters}---text you supply each
time you use the macro.  (This has nothing to do with the
@code{@@defmac} command, which is for documenting macros in the subject
of the manual; @pxref{Def Cmd Template}.)

@menu
* Defining Macros::             Both defining and undefining new commands.
* Invoking Macros::             Using a macro, once you've defined it.
@end menu


@node Defining Macros, Invoking Macros, Macros, Macros
@section Defining Macros
@cindex Defining macros
@cindex Macro definitions

@findex macro
You use the Texinfo @code{@@macro} command to define a macro.  For example:

@example
@@macro @var{macro-name}@{@var{param1}, @var{param2}, @dots{}@}
@var{text} @dots{} \@var{param1}\ @dots{}
@@end macro
@end example

The @dfn{parameters} @var{param1}, @var{param2}, @dots{} correspond to
arguments supplied when the macro is subsequently used in the document
(see the next section).

If a macro needs no parameters, you can define it either with an empty
list (@samp{@@macro foo @{@}}) or with no braces at all (@samp{@@macro
foo}).

@cindex Body of a macro
@cindex Mutually recursive macros
@cindex Recursion, mutual
The definition or @dfn{body} of the macro can contain any Texinfo
commands, including previously-defined macros.  (It is not possible to
have mutually recursive Texinfo macros.)  In the body, instances of a
parameter name surrounded by backslashes, as in @samp{\@var{param1}\} in
the example above, are replaced by the corresponding argument from the
macro invocation.

@findex unmacro
@cindex Macros, undefining
@cindex Undefining macros
You can undefine a macro @var{foo} with @code{@@unmacro @var{foo}}.
It is not an error to undefine a macro that is already undefined.
For example:

@example
@@unmacro foo
@end example


@node Invoking Macros, , Defining Macros, Macros
@section Invoking Macros
@cindex Invoking macros
@cindex Macro invocation

After a macro is defined (see the previous section), you can use
(@dfn{invoke}) it in your document like this:

@example
@@@var{macro-name} @{@var{arg1}, @var{arg2}, @dots{}@}
@end example

@noindent and the result will be just as if you typed the body of
@var{macro-name} at that spot.  For example:

@example
@@macro foo @{p, q@}
Together: \p\ & \q\.
@@end macro
@@foo@{a, b@}
@end example

@noindent produces:

@display
Together: a & b.
@end display

@cindex Backslash, and macros
Thus, the arguments and parameters are separated by commas and delimited
by braces; any whitespace after (but not before) a comma is ignored.  To
insert a comma, brace, or backslash in an argument, prepend a backslash,
as in

@example
@@@var{macro-name} @{\\\@{\@}\,@}
@end example

@noindent
which will pass the (almost certainly error-producing) argument
@samp{\@{@},} to @var{macro-name}.

If the macro is defined to take a single argument, and is invoked
without any braces, the entire rest of the line after the macro name is
supplied as the argument.  For example:

@example
@@macro bar @{p@}
Twice: \p\, \p\.
@@end macro
@@bar aah
@end example

@noindent produces:

@display
Twice: aah, aah.
@end display


@node Format/Print Hardcopy, Create an Info File, Macros, Top
@comment  node-name,  next,  previous,  up
@chapter Format and Print Hardcopy
@cindex Format and print hardcopy
@cindex Hardcopy, printing it
@cindex Making a printed manual
@cindex Sorting indices
@cindex Indices, sorting
@cindex @TeX{} index sorting
@pindex texindex

There are three major shell commands for making a printed manual from a
Texinfo file: one for converting the Texinfo file into a file that will be
printed, a second for sorting indices, and a third for printing the
formatted document.  When you use the shell commands, you can either
work directly in the operating system shell or work within a shell
inside GNU Emacs.@refill

If you are using GNU Emacs, you can use commands provided by Texinfo
mode instead of shell commands.  In addition to the three commands to
format a file, sort the indices, and print the result, Texinfo mode
offers key bindings for commands to recenter the output buffer, show the
print queue, and delete a job from the print queue.@refill

@menu
* Use TeX::                     Use @TeX{} to format for hardcopy.
* Format with tex/texindex::    How to format in a shell.
* Format with texi2dvi::        A simpler way to use the shell.
* Print with lpr::              How to print.
* Within Emacs::                How to format and print from an Emacs shell.
* Texinfo Mode Printing::       How to format and print in Texinfo mode.
* Compile-Command::             How to print using Emacs's compile command.
* Requirements Summary::        @TeX{} formatting requirements summary.
* Preparing for TeX::           What you need to do to use @TeX{}.
* Overfull hboxes::             What are and what to do with overfull hboxes.
* smallbook::                   How to print small format books and manuals.
* A4 Paper::                    How to print on European A4 paper.
* Cropmarks and Magnification::  How to print marks to indicate the size
                                of pages and how to print scaled up output.
@end menu

@node Use TeX, Format with tex/texindex, Format/Print Hardcopy, Format/Print Hardcopy
@ifinfo
@heading Use @TeX{}
@end ifinfo

The typesetting program called @TeX{} is used for formatting a Texinfo
file.  @TeX{} is a very powerful typesetting program and, if used right,
does an exceptionally good job.  @xref{Obtaining TeX, , How to Obtain
@TeX{}}, for information on how to obtain @TeX{}.@refill

The @code{makeinfo}, @code{texinfo-format-region}, and
@code{texinfo-format-buffer} commands read the very same @@-commands
in the Texinfo file as does @TeX{}, but process them differently to
make an Info file; see @ref{Create an Info File}.@refill

@node Format with tex/texindex, Format with texi2dvi, Use TeX, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Format using @code{tex} and @code{texindex}
@cindex Shell formatting with @code{tex} and @code{texindex}
@cindex Formatting with @code{tex} and @code{texindex}
@cindex DVI file

Format the Texinfo file with the shell command @code{tex} followed by
the name of the Texinfo file.  This command produces a formatted
@sc{dvi} file as well as several auxiliary files containing indices,
cross references, etc.  The @sc{dvi} file (for @dfn{DeVice Independent}
file) can be printed on a wide variety of printers.@refill

The @code{tex} formatting command itself does not sort the indices; it
writes an output file of unsorted index data.  This is a misfeature of
@TeX{}.  (The @code{texi2dvi} command automatically generates indices;
see @ref{Format with texi2dvi, , Format using @code{texi2dvi}}.)  To
generate a printed index after running the @code{tex} command, you first
need a sorted index to work from.  The @code{texindex} command sorts
indices.  (The source file @file{texindex.c} comes as part of the
standard GNU distribution and is usually installed when Emacs is
installed.)@refill
@pindex texindex
@ignore
Usage: texindex [-k] [-T tempdir] infile [-o outfile] ...

Each infile arg can optionally be followed by a `-o outfile' arg;
for each infile that is not followed by a -o arg, the infile name with
`s' (for `sorted') appended is used for the outfile.

-T dir is the directory to put temp files in, instead of /tmp.
-k means `keep tempfiles', for debugging.
@end ignore

The @code{tex} formatting command outputs unsorted index files under
names that obey a standard convention.  These names are the name of
your main input file to the @code{tex} formatting command, with
everything after the first period thrown away, and the two letter
names of indices added at the end.  For example, the raw index output
files for the input file @file{foo.texinfo} would be @file{foo.cp},
@file{foo.vr}, @file{foo.fn}, @file{foo.tp}, @file{foo.pg} and
@file{foo.ky}.  Those are exactly the arguments to give to
@code{texindex}.@refill

@need 1000
Or else, you can use @samp{??} as ``wild-cards'' and give the command in
this form:@refill

@example
texindex foo.??
@end example

@noindent
This command will run @code{texindex} on all the unsorted index files,
including any that you have defined yourself using @code{@@defindex}
or @code{@@defcodeindex}.  (You may execute @samp{texindex foo.??}
even if there are similarly named files with two letter extensions
that are not index files, such as @samp{foo.el}.  The @code{texindex}
command reports but otherwise ignores such files.)@refill

For each file specified, @code{texindex} generates a sorted index file
whose name is made by appending @samp{s} to the input file name.  The
@code{@@printindex} command knows to look for a file of that name.
@code{texindex} does not alter the raw index output file.@refill

After you have sorted the indices, you need to rerun the @code{tex}
formatting command on the Texinfo file.  This regenerates a formatted
@sc{dvi} file with up-to-date index entries.@footnote{If you use more
than one index and have cross references to an index other than the
first, you must run @code{tex} @emph{three times} to get correct output:
once to generate raw index data; again (after @code{texindex}) to output
the text of the indices and determine their true page numbers; and a
third time to output correct page numbers in cross references to them.
However, cross references to indices are rare.}@refill

To summarize, this is a three step process:

@enumerate
@item
Run the @code{tex} formatting command on the Texinfo file.  This
generates the formatted @sc{dvi} file as well as the raw index files
with two letter extensions.@refill

@item
Run the shell command @code{texindex} on the raw index files to sort
them.  This creates the corresponding sorted index files.@refill

@item
Rerun the @code{tex} formatting command on the Texinfo file.  This
regenerates a formatted @sc{dvi} file with the index entries in the
correct order.  This second run also corrects the page numbers for
the cross references.  (The tables of contents are always correct.)@refill
@end enumerate

You need not run @code{texindex} each time after you run the
@code{tex} formatting.  If you do not, on the next run, the @code{tex}
formatting command will use whatever sorted index files happen to
exist from the previous use of @code{texindex}.  This is usually
@sc{ok} while you are debugging.@refill

@node Format with texi2dvi, Print with lpr, Format with tex/texindex, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Format using @code{texi2dvi}
@pindex texi2dvi @r{(shell script)}

The @code{texi2dvi} command is a shell script that automatically runs
both @code{tex} and @code{texindex} as many times as necessary to
produce a @sc{dvi} file with up-to-date, sorted indices.  It simplifies
the @code{tex}---@code{texindex}---@code{tex} sequence described in the
previous section.

@need 1000
The syntax for @code{texi2dvi} is like this (where @samp{prompt$} is the
shell prompt):@refill

@example
prompt$ @kbd{texi2dvi @var{filename}@dots{}}
@end example

@node Print with lpr, Within Emacs, Format with texi2dvi, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Shell Print Using @code{lpr -d}
@pindex lpr @r{(@sc{dvi} print command)}

You can print a @sc{dvi} file with the @sc{dvi} print command.  The
precise printing command to use depends on your system; @samp{lpr -d} is
common.  The @sc{dvi} print command may require a file name without any
extension or with a @samp{.dvi} extension.@refill

@need 1200
The following commands, for example, sort the indices, format, and
print the @cite{Bison Manual} (where @samp{%} is the shell
prompt):@refill

@example
@group
% tex bison.texinfo
% texindex bison.??
% tex bison.texinfo
% lpr -d bison.dvi
@end group
@end example

@noindent
(Remember that the shell commands may be different at your site; but
these are commonly used versions.)@refill

@need 1000
Using the @code{texi2dvi} shell script, you simply need type:@refill

@example
@group
% texi2dvi bison.texinfo
% lpr -d bison.dvi
@end group
@end example

@node Within Emacs, Texinfo Mode Printing, Print with lpr, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section From an Emacs Shell @dots{}
@cindex Print, format from Emacs shell
@cindex Format, print from Emacs shell
@cindex Shell, format, print from
@cindex Emacs shell, format, print from
@cindex GNU Emacs shell, format, print from

You can give formatting and printing commands from a shell within GNU
Emacs.  To create a shell within Emacs, type @kbd{M-x shell}.  In this
shell, you can format and print the document.  @xref{Format/Print
Hardcopy, , Format and Print Hardcopy}, for details.@refill

You can switch to and from the shell buffer while @code{tex} is
running and do other editing.  If you are formatting a long document
on a slow machine, this can be very convenient.@refill

You can also use @code{texi2dvi} from an Emacs shell.  For example,
here is how to use @code{texi2dvi} to format and print @cite{Using and
Porting GNU CC} from a shell within Emacs (where @samp{%} is the shell
prompt):@refill

@example
@group
% texi2dvi gcc.texinfo
% lpr -d gcc.dvi
@end group
@end example
@ifinfo

@xref{Texinfo Mode Printing}, for more information about formatting
and printing in Texinfo mode.@refill
@end ifinfo

@node Texinfo Mode Printing, Compile-Command, Within Emacs, Format/Print Hardcopy
@section Formatting and Printing in Texinfo Mode
@cindex Region printing in Texinfo mode
@cindex Format and print in Texinfo mode
@cindex Print and format in Texinfo mode

Texinfo mode provides several predefined key commands for @TeX{}
formatting and printing.  These include commands for sorting indices,
looking at the printer queue, killing the formatting job, and
recentering the display of the buffer in which the operations
occur.@refill

@table @kbd
@item C-c C-t C-b
@itemx M-x texinfo-tex-buffer
Run @code{texi2dvi} on the current buffer.@refill

@item C-c C-t C-r
@itemx M-x texinfo-tex-region
Run @TeX{} on the current region.@refill

@item C-c C-t C-i
@itemx M-x texinfo-texindex
Sort the indices of a Texinfo file formatted with
@code{texinfo-tex-region}.@refill

@item C-c C-t C-p
@itemx M-x texinfo-tex-print
Print a @sc{dvi} file that was made with @code{texinfo-tex-region} or
@code{texinfo-tex-buffer}.@refill

@item C-c C-t C-q
@itemx M-x tex-show-print-queue
Show the print queue.@refill

@item C-c C-t C-d
@itemx M-x texinfo-delete-from-print-queue
Delete a job from the print queue; you will be prompted for the job
number shown by a preceding @kbd{C-c C-t C-q} command
(@code{texinfo-show-tex-print-queue}).@refill

@item C-c C-t C-k
@itemx M-x tex-kill-job
Kill the currently running @TeX{} job started by
@code{texinfo-tex-region} or @code{texinfo-tex-buffer}, or any other
process running in the Texinfo shell buffer.@refill

@item C-c C-t C-x
@itemx M-x texinfo-quit-job
Quit a @TeX{} formatting job that has stopped because of an error by
sending an @key{x} to it.  When you do this, @TeX{} preserves a record
of what it did in a @file{.log} file.@refill

@item C-c C-t C-l
@itemx M-x tex-recenter-output-buffer
Redisplay the shell buffer in which the @TeX{} printing and formatting
commands are run to show its most recent output.@refill
@end table

@need 1000
Thus, the usual sequence of commands for formatting a buffer is as
follows (with comments to the right):@refill

@example
@group
C-c C-t C-b             @r{Run @code{texi2dvi} on the buffer.}
C-c C-t C-p             @r{Print the @sc{dvi} file.}
C-c C-t C-q             @r{Display the printer queue.}
@end group
@end example

The Texinfo mode @TeX{} formatting commands start a subshell in Emacs
called the @file{*tex-shell*}.  The @code{texinfo-tex-command},
@code{texinfo-texindex-command}, and @code{tex-dvi-print-command}
commands are all run in this shell.

You can watch the commands operate in the @samp{*tex-shell*} buffer,
and you can switch to and from and use the @samp{*tex-shell*} buffer
as you would any other shell buffer.@refill

@need 1500
The formatting and print commands depend on the values of several variables.
The default values are:@refill

@example
@group
     @r{Variable}                              @r{Default value}

texinfo-texi2dvi-command                  "texi2dvi"
texinfo-tex-command                       "tex"
texinfo-texindex-command                  "texindex"
texinfo-delete-from-print-queue-command   "lprm"
texinfo-tex-trailer                       "@@bye"
tex-start-of-header                       "%**start"
tex-end-of-header                         "%**end"
tex-dvi-print-command                     "lpr -d"
tex-show-queue-command                    "lpq"
@end group
@end example

You can change the values of these variables with the @kbd{M-x
edit-options} command (@pxref{Edit Options, , Editing Variable Values,
emacs, The GNU Emacs Manual}), with the @kbd{M-x set-variable} command
(@pxref{Examining, , Examining and Setting Variables, emacs, The GNU
Emacs Manual}), or with your @file{.emacs} initialization file
(@pxref{Init File, , , emacs, The GNU Emacs Manual}).@refill

@node Compile-Command, Requirements Summary, Texinfo Mode Printing, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Using the Local Variables List
@cindex Local variables
@cindex Compile command for formatting
@cindex Format with the compile command

Yet another way to apply the @TeX{} formatting command to a Texinfo file
is to put that command in a @dfn{local variables list} at the end of the
Texinfo file.  You can then specify the @code{tex} or @code{texi2dvi}
commands as a @code{compile-command} and have Emacs run it by typing
@kbd{M-x compile}.  This creates a special shell called the
@file{*compilation*} buffer in which Emacs runs the compile command.
For example, at the end of the @file{gdb.texinfo} file, after the
@code{@@bye}, you could put the following:@refill

@example
@group
@@c Local Variables:
@@c compile-command: "texi2dvi gdb.texinfo"
@@c End:
@end group
@end example

@noindent
This technique is most often used by programmers who also compile programs
this way; see @ref{Compilation, , , emacs, The GNU Emacs Manual}.@refill

@node Requirements Summary, Preparing for TeX, Compile-Command, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section @TeX{} Formatting Requirements Summary
@cindex Requirements for formatting
@cindex Formatting requirements

Every Texinfo file that is to be input to @TeX{} must begin with a
@code{\input} command and must contain an @code{@@setfilename} command and
an @code{@@settitle} command:@refill

@example
\input texinfo
@@setfilename @var{arg-not-used-by-@TeX{}}
@@settitle @var{name-of-manual}
@end example

@noindent
The first command instructs @TeX{} to load the macros it needs to
process a Texinfo file, the second command opens auxiliary files, and
the third specifies the title of printed manual.

@need 1000
Every Texinfo file must end with a line that terminates @TeX{}
processing and forces out unfinished pages:@refill

@example
@@bye
@end example

Strictly speaking, these four lines are all a Texinfo file needs for
@TeX{}, besides the body.  (The @code{@@setfilename} line is the only
line that a Texinfo file needs for Info formatting.)@refill

Usually, the file's first line contains an @samp{@@c -*-texinfo-*-}
comment that causes Emacs to switch to Texinfo mode when you edit the
file.  In addition, the beginning usually includes an
@code{@@setchapternewpage} command, a title page, a copyright page, and
permissions.  Besides an @code{@@bye}, the end of a file usually
includes indices and a table of contents.@refill

@iftex
For more information, see
@ref{setchapternewpage, , @code{@@setchapternewpage}},
@ref{Headings, ,Page Headings},
@ref{Titlepage & Copyright Page},
@ref{Printing Indices & Menus}, and
@ref{Contents}.
@end iftex
@noindent
@ifinfo
For more information, see@*
@ref{setchapternewpage, , @code{@@setchapternewpage}},@*
@ref{Headings, ,Page Headings},@*
@ref{Titlepage & Copyright Page},@*
@ref{Printing Indices & Menus}, and@*
@ref{Contents}.
@end ifinfo

@node Preparing for TeX, Overfull hboxes, Requirements Summary, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Preparing to Use @TeX{}
@cindex Preparing to use @TeX{}
@cindex @TeX{} input initialization
@cindex @code{TEXINPUTS} environment variable
@vindex TEXINPUTS
@cindex @b{.profile} initialization file
@cindex @b{.cshrc} initialization file
@cindex Initialization file for @TeX{} input

@TeX{} needs to know where to find the @file{texinfo.tex} file
that you have told it to input with the @samp{\input texinfo} command
at the beginning of the first line.  The @file{texinfo.tex} file tells
@TeX{} how to handle @@-commands.  (@file{texinfo.tex} is
included in the standard GNU distributions.)@refill

Usually, the @file{texinfo.tex} file is put in the default directory
that contains @TeX{} macros (the @file{/usr/lib/tex/macros}
directory) when GNU Emacs or other GNU software is installed.
In this case, @TeX{} will
find the file and you do not need to do anything special.
Alternatively, you can put @file{texinfo.tex} in the directory in
which the Texinfo source file is located, and @TeX{} will find it
there.@refill

However, you may want to specify the location of the @code{\input} file
yourself.  One way to do this is to write the complete path for the file
after the @code{\input} command.  Another way is to set the
@code{TEXINPUTS} environment variable in your @file{.cshrc} or
@file{.profile} file.  The @code{TEXINPUTS} environment variable will tell
@TeX{} where to find the @file{texinfo.tex} file and any other file that
you might want @TeX{} to use.@refill

Whether you use a @file{.cshrc} or @file{.profile} file depends on
whether you use @code{csh}, @code{sh}, or @code{bash} for your shell
command interpreter.  When you use @code{csh}, it looks to the
@file{.cshrc} file for initialization information, and when you use
@code{sh} or @code{bash}, it looks to the @file{.profile} file.@refill

@need 1000
In a @file{.cshrc} file, you could use the following @code{csh} command
sequence:@refill

@example
setenv TEXINPUTS .:/usr/me/mylib:/usr/lib/tex/macros
@end example

@need 1000
In a @file{.profile} file, you could use the following @code{sh} command
sequence:

@example
@group
TEXINPUTS=.:/usr/me/mylib:/usr/lib/tex/macros
export TEXINPUTS
@end group
@end example

@noindent
This would cause @TeX{} to look for @file{\input} file first in the current
directory, indicated by the @samp{.}, then in a hypothetical user's
@file{me/mylib} directory, and finally in the system library.@refill

@node Overfull hboxes, smallbook, Preparing for TeX, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Overfull ``hboxes''
@cindex Overfull @samp{hboxes}
@cindex @samp{hboxes}, overfull
@cindex Final output

@TeX{} is sometimes unable to typeset a line without extending it into
the right margin.  This can occur when @TeX{} comes upon what it
interprets as a long word that it cannot hyphenate, such as an
electronic mail network address or a very long title.  When this
happens, @TeX{} prints an error message like this:@refill

@example
Overfull \hbox (20.76302pt too wide)
@end example

@noindent
(In @TeX{}, lines are in ``horizontal boxes'', hence the term, ``hbox''.
The backslash, @samp{\}, is the @TeX{} equivalent of @samp{@@}.)@refill

@TeX{} also provides the line number in the Texinfo source file and
the text of the offending line, which is marked at all the places that
@TeX{} knows how to hyphenate words.
@xref{Debugging with TeX, , Catching Errors with @TeX{} Formatting},
for more information about typesetting errors.@refill

If the Texinfo file has an overfull hbox, you can rewrite the sentence
so the overfull hbox does not occur, or you can decide to leave it.  A
small excursion into the right margin often does not matter and may not
even be noticeable.@refill

@cindex Black rectangle in hardcopy
@cindex Rectangle, ugly, black in hardcopy
However, unless told otherwise, @TeX{} will print a large, ugly, black
rectangle beside the line that contains the overfull hbox.  This is so
you will notice the location of the problem if you are correcting a
draft.@refill

@need 1000
@findex finalout
To prevent such a monstrosity from marring your final printout, write
the following in the beginning of the Texinfo file on a line of its own,
before the @code{@@titlepage} command:@refill

@example
@@finalout
@end example

@node smallbook, A4 Paper, Overfull hboxes, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Printing ``Small'' Books
@findex smallbook
@cindex Small book size
@cindex Book, printing small
@cindex Page sizes for books
@cindex Size of printed book

By default, @TeX{} typesets pages for printing in an 8.5 by 11 inch
format.  However, you can direct @TeX{} to typeset a document in a 7 by
9.25 inch format that is suitable for bound books by inserting the
following command on a line by itself at the beginning of the Texinfo
file, before the title page:@refill

@example
@@smallbook
@end example

@noindent
(Since regular sized books are often about 7 by 9.25 inches, this
command might better have been called the @code{@@regularbooksize}
command, but it came to be called the @code{@@smallbook} command by
comparison to the 8.5 by 11 inch format.)@refill

If you write the @code{@@smallbook} command between the
start-of-header and end-of-header lines, the Texinfo mode @TeX{}
region formatting command, @code{texinfo-tex-region}, will format the
region in ``small'' book size (@pxref{Start of Header}).@refill

The Free Software Foundation distributes printed copies of @cite{The GNU
Emacs Manual} and other manuals in the ``small'' book size.
@xref{smallexample & smalllisp, , @code{@@smallexample} and
@code{@@smalllisp}}, for information about commands that make it easier
to produce examples for a smaller manual.@refill

@node A4 Paper, Cropmarks and Magnification, smallbook, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Printing on A4 Paper
@cindex A4 paper, printing on
@cindex Paper size, European A4
@cindex European A4 paper
@findex afourpaper

You can tell @TeX{} to typeset a document for printing on European size
A4 paper with the @code{@@afourpaper} command.  Write the command on a
line by itself between @code{@@iftex} and @code{@@end iftex} lines near
the beginning of the Texinfo file, before the title page:@refill

For example, this is how you would write the header for this manual:@refill

@example
@group
\input texinfo    @@c -*-texinfo-*-
@@c %**start of header
@@setfilename texinfo
@@settitle Texinfo
@@syncodeindex vr fn
@@iftex
@@afourpaper
@@end iftex
@@c %**end of header
@end group
@end example

@node Cropmarks and Magnification, , A4 Paper, Format/Print Hardcopy
@comment  node-name,  next,  previous,  up
@section Cropmarks and Magnification

@findex cropmarks
@cindex Cropmarks for printing
@cindex Printing cropmarks
You can attempt to direct @TeX{} to print cropmarks at the corners of
pages with the @code{@@cropmarks} command.  Write the @code{@@cropmarks}
command on a line by itself between @code{@@iftex} and @code{@@end
iftex} lines near the beginning of the Texinfo file, before the title
page, like this:@refill

@example
@group
@@iftex
@@cropmarks
@@end iftex
@end group
@end example

This command is mainly for printers that typeset several pages on one
sheet of film; but you can attempt to use it to mark the corners of a
book set to 7 by 9.25 inches with the @code{@@smallbook} command.
(Printers will not produce cropmarks for regular sized output that is
printed on regular sized paper.)  Since different printing machines work
in different ways, you should explore the use of this command with a
spirit of adventure.  You may have to redefine the command in the
@file{texinfo.tex} definitions file.@refill

@findex mag @r{(@TeX{} command)}
@cindex Magnified printing
@cindex Larger or smaller pages
You can attempt to direct @TeX{} to typeset pages larger or smaller than
usual with the @code{\mag} @TeX{} command.  Everything that is typeset
is scaled proportionally larger or smaller.  (@code{\mag} stands for
``magnification''.)  This is @emph{not} a Texinfo @@-command, but is a
plain @TeX{} command that is prefixed with a backslash.  You have to
write this command between @code{@@tex} and @code{@@end tex}
(@pxref{Using Ordinary TeX Commands, , Using Ordinary @TeX{}
Commands}).@refill

Follow the @code{\mag} command with an @samp{=} and then a number that
is 1000 times the magnification you desire.  For example, to print pages
at 1.2 normal size, write the following near the beginning of the
Texinfo file, before the title page:@refill

@example
@group
@@tex
\mag=1200
@@end tex
@end group
@end example

With some printing technologies, you can print normal-sized copies that
look better than usual by using a larger-than-normal master.@refill

Depending on your system, @code{\mag} may not work or may work only at
certain magnifications.  Be prepared to experiment.@refill

@node Create an Info File, Install an Info File, Format/Print Hardcopy, Top
@comment  node-name,  next,  previous,  up
@chapter Creating an Info File
@cindex Creating an Info file
@cindex Info, creating an on-line file
@cindex Formatting a file for Info

@code{makeinfo} is a utility that converts a Texinfo file into an Info
file; @code{texinfo-format-region} and @code{texinfo-format-buffer} are
GNU Emacs functions that do the same.@refill

A Texinfo file must possess an @code{@@setfilename} line near its
beginning, otherwise the Info formatting commands will fail.@refill

For information on installing the Info file in the Info system, see
@ref{Install an Info File}.@refill

@menu
* makeinfo advantages::         @code{makeinfo} provides better error checking.
* Invoking makeinfo::           How to run @code{makeinfo} from a shell.
* makeinfo options::            Specify fill-column and other options.
* Pointer Validation::          How to check that pointers point somewhere.
* makeinfo in Emacs::           How to run @code{makeinfo} from Emacs.
* texinfo-format commands::     Two Info formatting commands written
                                  in Emacs Lisp are an alternative
                                  to @code{makeinfo}.
* Batch Formatting::            How to format for Info in Emacs Batch mode.
* Tag and Split Files::         How tagged and split files help Info
                                  to run better.
@end menu

@node makeinfo advantages, Invoking makeinfo, Create an Info File, Create an Info File
@ifinfo
@heading @code{makeinfo} Preferred
@end ifinfo

The @code{makeinfo} utility creates an Info file from a Texinfo source
file more quickly than either of the Emacs formatting commands and
provides better error messages.  We recommend it.  @code{makeinfo} is a
C program that is independent of Emacs.  You do not need to run Emacs to
use @code{makeinfo}, which means you can use @code{makeinfo} on machines
that are too small to run Emacs. You can run @code{makeinfo} in
any one of three ways: from an operating system shell, from a shell
inside Emacs, or by typing a key command in Texinfo mode in Emacs.
@refill

The @code{texinfo-format-region} and the @code{texinfo-format-buffer}
commands are useful if you cannot run @code{makeinfo}.  Also, in some
circumstances, they format short regions or buffers more quickly than
@code{makeinfo}.@refill

@node Invoking makeinfo, makeinfo options, makeinfo advantages, Create an Info File
@section Running @code{makeinfo} from a Shell

To create an Info file from a Texinfo file, type @code{makeinfo}
followed by the name of the Texinfo file.  Thus, to create the Info
file for Bison, type the following at the shell prompt (where @samp{%}
is the prompt):@refill

@example
% makeinfo bison.texinfo
@end example

(You can run a shell inside Emacs by typing @kbd{M-x
shell}.)@refill

@ifinfo
Sometimes you will want to specify options.  For example, if you wish
to discover which version of @code{makeinfo} you are using,
type:@refill

@example
% makeinfo --version
@end example

@xref{makeinfo options}, for more information.
@end ifinfo

@node makeinfo options, Pointer Validation, Invoking makeinfo, Create an Info File
@comment  node-name,  next,  previous,  up
@section Options for @code{makeinfo}
@cindex @code{makeinfo} options
@cindex Options for @code{makeinfo}

The @code{makeinfo} command takes a number of options.  Most often,
options are used to set the value of the fill column and specify the
footnote style.  Each command line option is a word preceded by
@samp{--}@footnote{@samp{--} has replaced @samp{+}, the old introductory
character, to maintain POSIX.2 compatibility without losing long-named
options.} or a letter preceded by @samp{-}.  You can use abbreviations
for the option names as long as they are unique.@refill

For example, you could use the following command to create an Info
file for @file{bison.texinfo} in which each line is filled to only 68
columns (where @samp{%} is the prompt):@refill

@example
% makeinfo --fill-column=68 bison.texinfo
@end example

You can write two or more options in sequence, like this:@refill

@example
% makeinfo --no-split --fill-column=70 @dots{}
@end example

@noindent
This would keep the Info file together as one possibly very long
file and would also set the fill column to 70.@refill

@iftex
If you wish to discover which version of @code{makeinfo}
you are using, type:@refill

@example
% makeinfo --version
@end example
@end iftex

The options are:@refill

@need 100
@table @code
@item -D @var{var}
Cause @var{var} to be defined.  This is equivalent to
@code{@@set @var{var}} in the Texinfo file.

@need 150
@item --error-limit @var{limit}
Set the maximum number of errors that @code{makeinfo} will report
before exiting (on the assumption that continuing would be useless).
The default number of errors that can be reported before
@code{makeinfo} gives up is 100.@refill

@need 150
@item --fill-column @var{width}
Specify the maximum number of columns in a line; this is the right-hand
edge of a line.  Paragraphs that are filled will be filled to this
width.  (Filling is the process of breaking up and connecting lines so
that lines are the same length as or shorter than the number specified
as the fill column.  Lines are broken between words.) The default value
for @code{fill-column} is 72.
@refill

@item --footnote-style @var{style}
Set the footnote style to @var{style}, either @samp{end} for the end
node style or @samp{separate} for the separate node style.  The value
set by this option overrides the value set in a Texinfo file by an
@code{@@footnotestyle} command.  When the footnote style is
@samp{separate}, @code{makeinfo} makes a new node containing the
footnotes found in the current node.  When the footnote style is
@samp{end}, @code{makeinfo} places the footnote references at the end
of the current node.@refill

@need 150
@item -I @var{dir}
Add @code{dir} to the directory search list for finding files that are
included using the @code{@@include} command.  By default,
@code{makeinfo} searches only the current directory.

@need 150
@item --no-headers
Do not include menus or node lines in the output.  This results in an
@sc{ascii} file that you cannot read in Info since it does not contain
the requisite nodes or menus; but you can print such a file in a
single, typewriter-like font and produce acceptable output.

@need 150
@item --no-split
Suppress the splitting stage of @code{makeinfo}.  Normally, large
output files (where the size is greater than 70k bytes) are split into
smaller subfiles, each one approximately 50k bytes.  If you specify
@samp{--no-split}, @code{makeinfo} will not split up the output
file.@refill

@need 100
@item --no-pointer-validate
@item --no-validate
Suppress the pointer-validation phase of @code{makeinfo}.  Normally,
after a Texinfo file is processed, some consistency checks are made to
ensure that cross references can be resolved, etc.
@xref{Pointer Validation}.@refill

@need 150
@item --no-warn
Suppress the output of warning messages.  This does @emph{not}
suppress the output of error messages, only warnings.  You might
want this if the file you are creating has examples of Texinfo cross
references within it, and the nodes that are referenced do not actually
exist.@refill

@item --no-number-footnotes
Suppress automatic footnote numbering.  By default, @code{makeinfo}
numbers each footnote sequentially in a single node, resetting the
current footnote number to 1 at the start of each node.

@need 150
@item --output @var{file}
@itemx -o @var{file}
Specify that the output should be directed to @var{file} and not to the
file name specified in the @code{@@setfilename} command found in the Texinfo
source.  @var{file} can be the special token @samp{-}, which specifies
standard output.

@need 150
@item --paragraph-indent @var{indent}
Set the paragraph indentation style to @var{indent}.  The value set by
this option overrides the value set in a Texinfo file by an
@code{@@paragraphindent} command.  The value of @var{indent} is
interpreted as follows:@refill

@itemize @bullet
@item
If the value of @var{indent} is @samp{asis}, do not change the
existing indentation at the starts of paragraphs.@refill

@item
If the value of @var{indent} is zero, delete any existing
indentation.@refill

@item
If the value of @var{indent} is greater than zero, indent each
paragraph by that number of spaces.@refill
@end itemize

@need 100
@item --reference-limit @var{limit}
Set the value of the number of references to a node that
@code{makeinfo} will make without reporting a warning.  If a node has more
than this number of references in it, @code{makeinfo} will make the
references but also report a warning.@refill

@need 150
@item -U @var{var}
Cause @var{var} to be undefined.  This is equivalent to
@code{@@clear @var{var}} in the Texinfo file.

@need 100
@item --verbose
Cause @code{makeinfo} to display messages saying what it is doing.
Normally, @code{makeinfo} only outputs messages if there are errors or
warnings.@refill

@need 100
@item --version
Report the version number of this copy of @code{makeinfo}.@refill
@end table

@node Pointer Validation, makeinfo in Emacs, makeinfo options, Create an Info File
@section Pointer Validation
@cindex Pointer validation with @code{makeinfo}
@cindex Validation of pointers

If you do not suppress pointer-validation, @code{makeinfo} will check
the validity of the final Info file.  Mostly, this means ensuring that
nodes you have referenced really exist.  Here is a complete list of what
is checked:@refill

@enumerate
@item
If a `Next', `Previous', or `Up' node reference is a reference to a
node in the current file and is not an external reference such as to
@file{(dir)}, then the referenced node must exist.@refill

@item
In every node, if the `Previous' node is different from the `Up' node,
then the `Previous' node must also be pointed to by a `Next' node.@refill

@item
Every node except the `Top' node must have an `Up' pointer.@refill

@item
The node referenced by an `Up' pointer must contain a reference to the
current node in some manner other than through a `Next' reference.
This includes menu entries and cross references.@refill

@item
If the `Next' reference of a node is not the same as the `Next' reference
of the `Up' reference, then the node referenced by the `Next' pointer
must have a `Previous' pointer that points back to the current node.
This rule allows the last node in a section to point to the first node
of the next chapter.@refill
@end enumerate

@node makeinfo in Emacs, texinfo-format commands, Pointer Validation, Create an Info File
@section Running @code{makeinfo} inside Emacs
@cindex Running @code{makeinfo} in Emacs
@cindex @code{makeinfo} inside Emacs
@cindex Shell, running @code{makeinfo} in

You can run @code{makeinfo} in GNU Emacs Texinfo mode by using either the
@code{makeinfo-region} or the @code{makeinfo-buffer} commands.  In
Texinfo mode, the commands are bound to @kbd{C-c C-m C-r} and @kbd{C-c
C-m C-b} by default.@refill

@table @kbd
@item C-c C-m C-r
@itemx M-x makeinfo-region
Format the current region for Info.@refill
@findex makeinfo-region

@item C-c C-m C-b
@itemx M-x makeinfo-buffer
Format the current buffer for Info.@refill
@findex makeinfo-buffer
@end table

When you invoke either @code{makeinfo-region} or
@code{makeinfo-buffer}, Emacs prompts for a file name, offering the
name of the visited file as the default.  You can edit the default
file name in the minibuffer if you wish, before typing @key{RET} to
start the @code{makeinfo} process.@refill

The Emacs @code{makeinfo-region} and @code{makeinfo-buffer} commands
run the @code{makeinfo} program in a temporary shell buffer.  If
@code{makeinfo} finds any errors, Emacs displays the error messages in
the temporary buffer.@refill

@cindex Errors, parsing
@cindex Parsing errors
@findex next-error
You can parse the error messages by typing @kbd{C-x `}
(@code{next-error}).  This causes Emacs to go to and position the
cursor on the line in the Texinfo source that @code{makeinfo} thinks
caused the error.  @xref{Compilation, , Running @code{make} or
Compilers Generally, emacs, The GNU Emacs Manual}, for more
information about using the @code{next-error} command.@refill

In addition, you can kill the shell in which the @code{makeinfo}
command is running or make the shell buffer display its most recent
output.@refill

@table @kbd
@item C-c C-m C-k
@itemx M-x makeinfo-kill-job
@findex makeinfo-kill-job
Kill the current running @code{makeinfo} job created by
@code{makeinfo-region} or @code{makeinfo-buffer}.@refill

@item C-c C-m C-l
@itemx M-x makeinfo-recenter-output-buffer
@findex makeinfo-recenter-output-buffer
Redisplay the @code{makeinfo} shell buffer to display its most recent
output.@refill
@end table

@noindent
(Note that the parallel commands for killing and recentering a @TeX{}
job are @kbd{C-c C-t C-k} and @kbd{C-c C-t C-l}.  @xref{Texinfo Mode
Printing}.)@refill

You can specify options for @code{makeinfo} by setting the
@code{makeinfo-options} variable with either the @kbd{M-x
edit-options} or the @kbd{M-x set-variable} command, or by setting the
variable in your @file{.emacs} initialization file.@refill

For example, you could write the following in your @file{.emacs} file:@refill

@example
@group
(setq makeinfo-options
      "--paragraph-indent=0 --no-split
       --fill-column=70 --verbose")
@end group
@end example

@c If you write these three cross references using xref, you see
@c three references to the same named manual, which looks strange.
@iftex
For more information, see @ref{makeinfo options, , Options for
@code{makeinfo}}, as well as ``Editing Variable Values,''``Examining and
Setting Variables,'' and ``Init File'' in the @cite{The GNU Emacs
Manual}.
@end iftex
@noindent
@ifinfo
For more information, see@*
@ref{Edit Options, , Editing Variable Values, emacs, The GNU Emacs Manual},@*
@ref{Examining, , Examining and Setting Variables, emacs, The GNU Emacs Manual},@*
@ref{Init File, , , emacs, The GNU Emacs Manual}, and@*
@ref{makeinfo options, , Options for @code{makeinfo}}.
@end ifinfo

@node texinfo-format commands, Batch Formatting, makeinfo in Emacs, Create an Info File
@comment  node-name,  next,  previous,  up
@section The @code{texinfo-format@dots{}} Commands
@findex texinfo-format-region
@findex texinfo-format-buffer

In GNU Emacs in Texinfo mode, you can format part or all of a Texinfo
file with the @code{texinfo-format-region} command.  This formats the
current region and displays the formatted text in a temporary buffer
called @samp{*Info Region*}.@refill

Similarly, you can format a buffer with the
@code{texinfo-format-buffer} command.  This command creates a new
buffer and generates the Info file in it.  Typing @kbd{C-x C-s} will
save the Info file under the name specified by the
@code{@@setfilename} line which must be near the beginning of the
Texinfo file.@refill

@table @kbd
@item C-c C-e C-r
@itemx @code{texinfo-format-region}
Format the current region for Info.
@findex texinfo-format-region

@item C-c C-e C-b
@itemx @code{texinfo-format-buffer}
Format the current buffer for Info.
@findex texinfo-format-buffer
@end table

The @code{texinfo-format-region} and @code{texinfo-format-buffer}
commands provide you with some error checking, and other functions can
provide you with further help in finding formatting errors.  These
procedures are described in an appendix; see @ref{Catching Mistakes}.
However, the @code{makeinfo} program is often faster and
provides better error checking (@pxref{makeinfo in Emacs}).@refill

@node Batch Formatting, Tag and Split Files, texinfo-format commands, Create an Info File
@comment  node-name,  next,  previous,  up
@section Batch Formatting
@cindex Batch formatting for Info
@cindex Info batch formatting

You can format Texinfo files for Info using @code{batch-texinfo-format}
and Emacs Batch mode.  You can run Emacs in Batch mode from any shell,
including a shell inside of Emacs.  (@xref{Command Switches, , Command
Line Switches and Arguments, emacs, The GNU Emacs Manual}.)@refill

Here is the command to format all the files that end in @file{.texinfo}
in the current directory (where @samp{%} is the shell prompt):@refill

@example
% emacs -batch -funcall batch-texinfo-format *.texinfo
@end example

@noindent
Emacs processes all the files listed on the command line, even if an
error occurs while attempting to format some of them.@refill

Run @code{batch-texinfo-format} only with Emacs in Batch mode as shown;
it is not interactive.  It kills the Batch mode Emacs on completion.@refill

@code{batch-texinfo-format} is convenient if you lack @code{makeinfo}
and want to format several Texinfo files at once.  When you use Batch
mode, you create a new Emacs process.  This frees your current Emacs, so
you can continue working in it.  (When you run
@code{texinfo-format-region} or @code{texinfo-format-buffer}, you cannot
use that Emacs for anything else until the command finishes.)@refill

@node Tag and Split Files, , Batch Formatting, Create an Info File
@comment  node-name,  next,  previous,  up
@section Tag Files and Split Files
@cindex Making a tag table automatically
@cindex Tag table, making automatically

If a Texinfo file has more than 30,000 bytes,
@code{texinfo-format-buffer} automatically creates a tag table
for its Info file;  @code{makeinfo} always creates a tag table.  With
a @dfn{tag table}, Info can jump to new nodes more quickly than it can
otherwise.@refill

@cindex Indirect subfiles
In addition, if the Texinfo file contains more than about 70,000
bytes, @code{texinfo-format-buffer} and @code{makeinfo} split the
large Info file into shorter @dfn{indirect} subfiles of about 50,000
bytes each.  Big files are split into smaller files so that Emacs does
not need to make a large buffer to hold the whole of a large Info
file; instead, Emacs allocates just enough memory for the small, split
off file that is needed at the time.  This way, Emacs avoids wasting
memory when you run Info.  (Before splitting was implemented, Info
files were always kept short and @dfn{include files} were designed as
a way to create a single, large printed manual out of the smaller Info
files.  @xref{Include Files}, for more information.  Include files are
still used for very large documents, such as @cite{The Emacs Lisp
Reference Manual}, in which each chapter is a separate file.)@refill

When a file is split, Info itself makes use of a shortened version of
the original file that contains just the tag table and references to
the files that were split off.  The split off files are called
@dfn{indirect} files.@refill

The split off files have names that are created by appending @w{@samp{-1}},
@w{@samp{-2}}, @w{@samp{-3}} and so on to the file name specified by the
@code{@@setfilename} command.  The shortened version of the original file
continues to have the name specified by @code{@@setfilename}.@refill

At one stage in writing this document, for example, the Info file was saved
as @file{test-texinfo} and that file looked like this:@refill

@example
@group
Info file: test-texinfo,    -*-Text-*-
produced by texinfo-format-buffer
from file: new-texinfo-manual.texinfo

^_
Indirect:
test-texinfo-1: 102
test-texinfo-2: 50422
@end group
@group
test-texinfo-3: 101300
^_^L
Tag table:
(Indirect)
Node: overview^?104
Node: info file^?1271
@end group
@group
Node: printed manual^?4853
Node: conventions^?6855
@dots{}
@end group
@end example

@noindent
(But @file{test-texinfo} had far more nodes than are shown here.)  Each of
the split off, indirect files, @file{test-texinfo-1},
@file{test-texinfo-2}, and @file{test-texinfo-3}, is listed in this file
after the line that says @samp{Indirect:}.  The tag table is listed after
the line that says @samp{Tag table:}. @refill

In the list of indirect files, the number following the file name
records the cumulative number of bytes in the preceding indirect files,
not counting the file list itself, the tag table, or the permissions
text in each file.  In the tag table, the number following the node name
records the location of the beginning of the node, in bytes from the
beginning.@refill

If you are using @code{texinfo-format-buffer} to create Info files,
you may want to run the @code{Info-validate} command.  (The
@code{makeinfo} command does such a good job on its own, you do not
need @code{Info-validate}.)  However, you cannot run the @kbd{M-x
Info-validate} node-checking command on indirect files.  For
information on how to prevent files from being split and how to
validate the structure of the nodes, see @ref{Using
Info-validate}.@refill


@node Install an Info File, Command List, Create an Info File, Top
@comment  node-name,  next,  previous,  up
@chapter Installing an Info File
@cindex Installing an Info file
@cindex Info file installation
@cindex @file{dir} directory for Info installation

Info files are usually kept in the @file{info} directory.  You can read
Info files using the standalone Info program or the Info reader built
into Emacs.  (@inforef{Top, info, info}, for an introduction to Info.)

@menu
* Directory file::              The top level menu for all Info files.
* New Info File::               Listing a new info file.
* Other Info Directories::      How to specify Info files that are
                                  located in other directories.
* Installing Dir Entries::      How to specify what menu entry to add
                                  to the Info directory.
* Invoking install-info::       @code{install-info} options.
@end menu

@node Directory file, New Info File, Install an Info File, Install an Info File
@ifinfo
@heading The @file{dir} File
@end ifinfo

For Info to work, the @file{info} directory must contain a file that
serves as a top level directory for the Info system.  By convention,
this file is called @file{dir}.  (You can find the location of this file
within Emacs by typing @kbd{C-h i} to enter Info and then typing
@kbd{C-x C-f} to see the pathname to the @file{info} directory.)

The @file{dir} file is itself an Info file.  It contains the top level
menu for all the Info files in the system.  The menu looks like
this:@refill

@example
@group
* Menu:

* Info:    (info).     Documentation browsing system.
* Emacs:   (emacs).    The extensible, self-documenting
                       text editor.
* Texinfo: (texinfo).  With one source file, make
                       either a printed manual using
                       TeX or an Info file.
@dots{}
@end group
@end example

Each of these menu entries points to the `Top' node of the Info file
that is named in parentheses.  (The menu entry does not need to
specify the `Top' node, since Info goes to the `Top' node if no node
name is mentioned.  @xref{Other Info Files, , Nodes in Other Info
Files}.)@refill

Thus, the @samp{Info} entry points to the `Top' node of the
@file{info} file and the @samp{Emacs} entry points to the `Top' node
of the @file{emacs} file.@refill

In each of the Info files, the `Up' pointer of the `Top' node refers
back to the @code{dir} file.  For example, the line for the `Top'
node of the Emacs manual looks like this in Info:@refill

@example
File: emacs  Node: Top, Up: (DIR), Next: Distrib
@end example

@noindent
(Note that in this case, the @file{dir} file name is written in upper
case letters---it can be written in either upper or lower case.  Info
has a feature that it will change the case of the file name to lower
case if it cannot find the name as written.)@refill
@c !!! Can any file name be written in upper or lower case,
@c     or is dir a special case?
@c     Yes, apparently so, at least with Gillespie's Info.  --rjc 24mar92


@node New Info File, Other Info Directories, Directory file, Install an Info File
@section Listing a New Info File
@cindex Adding a new info file
@cindex Listing a new info file
@cindex New info file, listing it in @file{dir} file
@cindex Info file, listing new one
@cindex @file{dir} file listing

To add a new Info file to your system, you must write a menu entry to
add to the menu in the @file{dir} file in the @file{info} directory.
For example, if you were adding documentation for GDB, you would write
the following new entry:@refill

@example
* GDB: (gdb).           The source-level C debugger.
@end example

@noindent
The first part of the menu entry is the menu entry name, followed by a
colon.  The second part is the name of the Info file, in parentheses,
followed by a period.  The third part is the description.

The name of an Info file often has a @file{.info} extension.  Thus, the
Info file for GDB might be called either @file{gdb} or @file{gdb.info}.
The Info reader programs automatically try the file name both with and
without @file{.info}; so it is better to avoid clutter and not to write
@samp{.info} explicitly in the menu entry.  For example, the GDB menu
entry should use just @samp{gdb} for the file name, not @samp{gdb.info}.


@node Other Info Directories, Installing Dir Entries, New Info File, Install an Info File
@comment  node-name,  next,  previous,  up
@section Info Files in Other Directories
@cindex Installing Info in another directory
@cindex Info installed in another directory
@cindex Another Info directory

If an Info file is not in the @file{info} directory, there are three
ways to specify its location:@refill

@itemize @bullet
@item
Write the pathname in the @file{dir} file as the second part of the
menu.@refill

@item
If you are using Emacs, list the name of the file in a second @file{dir}
file, in its directory; and then add the name of that directory to the
@code{Info-directory-list} variable in your personal or site
initialization file.

This tells Emacs's Info reader where to look for @file{dir}
files.  Emacs merges the files named @file{dir} from each of the listed
directories.  (In Emacs Version 18, you can set the
@code{Info-directory} variable to the name of only one
directory.)@refill

@item
Specify the @file{info} directory name in the @code{INFOPATH}
environment variable in your @file{.profile} or @file{.cshrc}
initialization file.  (Only you and others who set this environment
variable will be able to find Info files whose location is specified
this way.)@refill
@end itemize

For example, to reach a test file in the @file{~bob/manuals}
directory, you could add an entry like this to the menu in the
@file{dir} file:@refill

@example
* Test: (/home/bob/manuals/info-test).  Bob's own test file.
@end example

@noindent
In this case, the absolute file name of the @file{info-test} file is
written as the second part of the menu entry.@refill

@vindex Info-directory-list
Alternatively, you could write the following in your @file{.emacs}
file:@refill

@example
@group
(setq Info-directory-list
      '("/home/bob/manuals"
        "/usr/local/emacs/info"))
@end group
@end example

@c reworded to avoid overfill hbox
This tells Emacs to merge the @file{dir} file from the
@file{/home/bob/manuals} directory with the @file{dir} file from the
@file{"/usr/local/emacs/info}" directory.  Info will list the
@file{/home/bob/manuals/info-test} file as a menu entry in the
@file{/home/bob/manuals/dir} file.@refill

@vindex INFOPATH
Finally, you can tell Info where to look by setting the
@code{INFOPATH} environment variable in your @file{.cshrc} or
@file{.profile} file.@refill

If you use @code{sh} or @code{bash} for your shell command interpreter,
you must set the @code{INFOPATH} environment variable in the
@file{.profile} initialization file; but if you use @code{csh}, you must
set the variable in the @file{.cshrc} initialization file.  The two
files use slightly different command formats.@refill

@itemize @bullet
@item
In a @file{.cshrc} file, you could set the @code{INFOPATH}
variable as follows:@refill

@smallexample
setenv INFOPATH .:~bob/manuals:/usr/local/emacs/info
@end smallexample

@item
In a @file{.profile} file, you would achieve the same effect by
writing:@refill

@smallexample
INFOPATH=.:~bob/manuals:/usr/local/emacs/info
export INFOPATH
@end smallexample
@end itemize

@noindent
The @samp{.}  indicates the current directory.  Emacs uses the
@code{INFOPATH} environment variable to initialize the value of Emacs's
own @code{Info-directory-list} variable.


@node Installing Dir Entries, Invoking install-info, Other Info Directories, Install an Info File
@section Installing Info Directory Files

When you install an Info file onto your system, you can use the program
@code{install-info} to update the Info directory file @file{dir}.
Normally the makefile for the package runs @code{install-info}, just
after copying the Info file into its proper installed location.

@findex dircategory
@findex direntry
In order for the Info file to work with @code{install-info}, you should
use the commands @code{@@dircategory} and @code{@@direntry} in the
Texinfo source file.  Use @code{@@direntry} to specify the menu entry to
add to the Info directory file, and use @code{@@dircategory} to specify
which part of the Info directory to put it in.  Here is how these
commands are used in this manual:

@smallexample
@@dircategory Texinfo documentation system
@@direntry
* Texinfo: (texinfo).           The GNU documentation format.
* install-info: (texinfo)Invoking install-info. @dots{}
@dots{}
@@end direntry
@end smallexample

Here's what this produces in the Info file:

@smallexample
INFO-DIR-SECTION Texinfo documentation system
START-INFO-DIR-ENTRY
* Texinfo: (texinfo).           The GNU documentation format.
* install-info: (texinfo)Invoking install-info. @dots{}
@dots{}
END-INFO-DIR-ENTRY
@end smallexample

@noindent
The @code{install-info} program sees these lines in the Info file, and
that is how it knows what to do.

Always use the @code{@@direntry} and @code{@@dircategory} commands near
the beginning of the Texinfo input, before the first @code{@@node}
command.  If you use them later on in the input, @code{install-info}
will not notice them.

If you use @code{@@dircategory} more than once in the Texinfo source,
each usage specifies one category; the new menu entry is added to the
Info directory file in each of the categories you specify.  If you use
@code{@@direntry} more than once, each usage specifies one menu entry;
each of these menu entries is added to the directory in each of the
specified categories.


@node Invoking install-info, , Installing Dir Entries, Install an Info File
@section Invoking install-info

@pindex install-info

@code{install-info} inserts menu entries from an Info file into the
top-level @file{dir} file in the Info system (see the previous sections
for an explanation of how the @file{dir} file works).  It's most often
run as part of software installation, or when constructing a dir file
for all manuals on a system.  Synopsis:

@example
install-info [@var{option}]@dots{} [@var{info-file} [@var{dir-file}]]
@end example

If @var{info-file} or @var{dir-file} are not specified, the various
options (described below) that define them must be.  There are no
compile-time defaults, and standard input is never used.
@code{install-info} can read only one info file and write only one dir
file per invocation.

Options:

@table @samp
@item --delete
@opindex --delete
Only delete existing entries in @var{info-file}; don't insert any new
entries.

@item --dir-file=@var{name}
@opindex --dir-file=@var{name}
Specify file name of the Info directory file.  This is equivalent to
using the @var{dir-file} argument.

@item --entry=@var{text}
@opindex --entry=@var{text}
Insert @var{text} as an Info directory entry; @var{text} should have the
form of an Info menu item line plus zero or more extra lines starting
with whitespace.  If you specify more than one entry, they are all
added.  If you don't specify any entries, they are determined from
information in the Info file itself.

@item --help
@opindex --help
Display a usage message listing basic usage and all available options,
then exit successfully.

@item --info-file=@var{file}
@opindex --info-file=@var{file}
Specify Info file to install in the directory.
This is equivalent to using the @var{info-file} argument.

@item --info-dir=@var{dir}
@opindex --info-dir=@var{dir}
Equivalent to @samp{--dir-file=@var{dir}/dir}.

@item --item=@var{text}
@opindex --item=@var{text}
Same as --entry=@var{text}.  An Info directory entry is actually a menu
item.

@item --quiet
@opindex --quiet
Suppress warnings.

@item --remove
@opindex --remove
Same as --delete.

@item --section=@var{sec}
@opindex --section=@var{sec}
Put this file's entries in section @var{sec} of the directory.  If you
specify more than one section, all the entries are added in each of the
sections.  If you don't specify any sections, they are determined from
information in the Info file itself.

@item --version
@opindex --version
@cindex version number, finding
Display version information and exit successfully.

@end table


@c ================ Appendix starts here ================

@node Command List, Tips, Install an Info File, Top
@appendix @@-Command List
@cindex Alphabetical @@-command list
@cindex List of  @@-commands
@cindex @@-command list

Here is an alphabetical list of the @@-commands in Texinfo.  Square
brackets, @t{[}@w{ }@t{]}, indicate optional arguments; an ellipsis,
@samp{@dots{}}, indicates repeated text.@refill

@sp 1
@table @code
@item @@@var{whitespace}
An @code{@@} followed by a space, tab, or newline produces a normal,
stretchable, interword space.  @xref{Multiple Spaces}.

@item @@!
Generate an exclamation point that really does end a sentence (usually
after an end-of-sentence capital letter).  @xref{Ending a Sentence}.

@item @@"
@itemx @@'
Generate an umlaut or acute accent, respectively, over the next
character, as in @"o and @'o.  @xref{Inserting Accents}.

@item @@*
Force a line break. Do not end a paragraph that uses @code{@@*} with
an @code{@@refill} command.  @xref{Line Breaks}.@refill

@item @@,@{@var{c}@}
Generate a cedilla accent under @var{c}, as in @,{c}.  @xref{Inserting
Accents}.

@item @@-
Insert a discretionary hyphenation point.  @xref{- and hyphenation}.

@item @@.
Produce a period that really does end a sentence (usually after an
end-of-sentence capital letter).  @xref{Ending a Sentence}.

@item @@:
Indicate to @TeX{} that an immediately preceding period, question
mark, exclamation mark, or colon does not end a sentence.  Prevent
@TeX{} from inserting extra whitespace as it does at the end of a
sentence.  The command has no effect on the Info file output.
@xref{Not Ending a Sentence}.@refill

@item @@=
Generate a macro (bar) accent over the next character, as in @=o.
@xref{Inserting Accents}.

@item @@?
Generate a question mark that really does end a sentence (usually after
an end-of-sentence capital letter).  @xref{Ending a Sentence}.

@item @@@@
Stands for an at sign, @samp{@@}.@*
@xref{Braces Atsigns, , Inserting @@ and braces}.

@item @@^
@itemx @@`
Generate a circumflex (hat) or grave accent, respectively, over the next
character, as in @^o.
@xref{Inserting Accents}.

@item @@@{
Stands for a left brace, @samp{@{}.@*
@xref{Braces Atsigns, , Inserting @@ and braces}.

@item @@@}
Stands for a right-hand brace, @samp{@}}.@*
@xref{Braces Atsigns, , Inserting @@ and braces}.

@item @@=
Generate a tilde accent over the next character, as in @~N.
@xref{Inserting Accents}.

@item @@AA@{@}
@itemx @@aa@{@}
Generate the uppercase and lowercase Scandinavian A-ring letters,
respectively: @AA{}, @aa{}.  @xref{Inserting Accents}.

@item @@AE@{@}
@itemx @@ae@{@}
Generate the uppercase and lowercase AE ligatures, respectively:
@AE{}, @ae{}.  @xref{Inserting Accents}.

@item @@appendix @var{title}
Begin an appendix.  The title appears in the table
of contents of a printed manual.  In Info, the title is
underlined with asterisks.  @xref{unnumbered & appendix, , The
@code{@@unnumbered} and @code{@@appendix} Commands}.@refill

@item @@appendixsec @var{title}
@itemx @@appendixsection @var{title}
Begin an appendix section within an appendix.  The section title appears
in the table of contents of a printed manual.  In Info, the title is
underlined with equal signs.  @code{@@appendixsection} is a longer
spelling of the @code{@@appendixsec} command.  @xref{unnumberedsec
appendixsec heading, , Section Commands}.@refill

@item @@appendixsubsec @var{title}
Begin an appendix subsection within an appendix.  The title appears
in the table of contents of a printed manual.  In Info, the title is
underlined with hyphens.  @xref{unnumberedsubsec appendixsubsec
subheading, , Subsection Commands}.@refill

@item @@appendixsubsubsec @var{title}
Begin an appendix subsubsection within a subappendix.  The title
appears in the table of contents of a printed manual.  In Info, the
title is underlined with periods.  @xref{subsubsection,, The `subsub'
Commands}.@refill

@item @@asis
Used following @code{@@table}, @code{@@ftable}, and @code{@@vtable} to
print the table's first column without highlighting (``as is'').
@xref{Two-column Tables, , Making a Two-column Table}.@refill

@item @@author @var{author}
Typeset @var{author} flushleft and underline it.  @xref{title
subtitle author, , The @code{@@title} and @code{@@author}
Commands}.@refill

@item @@b@{@var{text}@}
Print @var{text} in @b{bold} font.  No effect in Info.  @xref{Fonts}.@refill

@ignore
@item @@br
Force a paragraph break.  If used within a line, follow @code{@@br}
with braces.  @xref{br, , @code{@@br}}.@refill
@end ignore

@item @@bullet@{@}
Generate a large round dot, or the closest possible
thing to one.  @xref{bullet, , @code{@@bullet}}.@refill

@item @@bye
Stop formatting a file.  The formatters do not see the contents of a
file following an @code{@@bye} command.  @xref{Ending a File}.@refill

@item @@c @var{comment}
Begin a comment in Texinfo.  The rest of the line does not appear in
either the Info file or the printed manual.  A synonym for
@code{@@comment}.  @xref{Comments, , Comments}.@refill

@item @@cartouche
Highlight an example or quotation by drawing a box with rounded
corners around it.  Pair with @code{@@end cartouche}.  No effect in
Info.  @xref{cartouche, , Drawing Cartouches Around Examples}.)@refill

@item @@center @var{line-of-text}
Center the line of text following the command.
@xref{titlefont center sp, , @code{@@center}}.@refill

@item @@centerchap @var{line-of-text}
Like @code{@@chapter}, but centers the chapter title.  @xref{chapter,,
@code{@@chapter}}.

@item @@chapheading @var{title}
Print a chapter-like heading in the text, but not in the table of
contents of a printed manual.  In Info, the title is underlined with
asterisks.  @xref{majorheading & chapheading, , @code{@@majorheading}
and @code{@@chapheading}}.@refill

@item @@chapter @var{title}
Begin a chapter.  The chapter title appears in the table of
contents of a printed manual.  In Info, the title is underlined with
asterisks.  @xref{chapter, , @code{@@chapter}}.@refill

@item @@cindex @var{entry}
Add @var{entry} to the index of concepts.  @xref{Index Entries, ,
Defining the Entries of an Index}.@refill

@item @@cite@{@var{reference}@}
Highlight the name of a book or other reference that lacks a
companion Info file.  @xref{cite, , @code{@@cite}}.@refill

@item @@clear @var{flag}
Unset @var{flag}, preventing the Texinfo formatting commands from
formatting text between subsequent pairs of @code{@@ifset @var{flag}}
and @code{@@end ifset} commands, and preventing
@code{@@value@{@var{flag}@}} from expanding to the value to which
@var{flag} is set.
@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill

@item @@code@{@var{sample-code}@}
Highlight text that is an expression, a syntactically complete token
of a program, or a program name.  @xref{code, , @code{@@code}}.@refill

@item @@comment @var{comment}
Begin a comment in Texinfo.  The rest of the line does not appear in
either the Info file or the printed manual.  A synonym for @code{@@c}.
@xref{Comments, , Comments}.@refill

@item @@contents
Print a complete table of contents.  Has no effect in Info, which uses
menus instead.  @xref{Contents, , Generating a Table of
Contents}.@refill

@item @@copyright@{@}
Generate a copyright symbol.  @xref{copyright symbol, ,
@code{@@copyright}}.@refill

@ignore
@item @@ctrl@{@var{ctrl-char}@}
Describe an @sc{ascii} control character.  Insert actual control character
into Info file.  @xref{ctrl, , @code{@@ctrl}}.@refill
@end ignore

@item @@defcodeindex @var{index-name}
Define a new index and its indexing command.  Print entries in an
@code{@@code} font.  @xref{New Indices, , Defining New
Indices}.@refill

@item @@defcv @var{category} @var{class} @var{name}
@itemx @@defcvx @var{category} @var{class} @var{name}
Format a description for a variable associated with a class in
object-oriented programming.  Takes three arguments: the category of
thing being defined, the class to which it belongs, and its name.
@xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}.

@item @@deffn @var{category} @var{name} @var{arguments}@dots{}
@itemx @@deffnx @var{category} @var{name} @var{arguments}@dots{}
Format a description for a function, interactive command, or similar
entity that may take arguments.  @code{@@deffn} takes as arguments the
category of entity being described, the name of this particular
entity, and its arguments, if any.  @xref{Definition Commands}.@refill

@item @@defindex @var{index-name}
Define a new index and its indexing command.  Print entries in a roman
font.  @xref{New Indices, , Defining New Indices}.@refill

@c Unused so far as I can see and unsupported by makeinfo -- karl, 15sep96.
@item @@definfoenclose @var{new-command}, @var{before}, @var{after},
Create new @@-command for Info that marks text by enclosing it in
strings that precede and follow the text.  Write definition inside of
@code{@@ifinfo} @dots{} @code{@@end ifinfo}. @xref{Customized
Highlighting}.@refill

@item @@defivar @var{class} @var{instance-variable-name}
@itemx @@defivarx @var{class} @var{instance-variable-name}
This command formats a description for an instance variable in
object-oriented programming.  The command is equivalent to @samp{@@defcv
@{Instance Variable@} @dots{}}.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@defmac @var{macro-name} @var{arguments}@dots{}
@itemx @@defmacx @var{macro-name} @var{arguments}@dots{}
Format a description for a macro.  The command is equivalent to
@samp{@@deffn Macro @dots{}}.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@defmethod @var{class} @var{method-name} @var{arguments}@dots{}
@itemx @@defmethodx @var{class} @var{method-name} @var{arguments}@dots{}
Format a description for a method in object-oriented programming.  The
command is equivalent to @samp{@@defop Method @dots{}}.  Takes as
arguments the name of the class of the method, the name of the
method, and its arguments, if any.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{}
@itemx @@defopx @var{category} @var{class} @var{name} @var{arguments}@dots{}
Format a description for an operation in object-oriented programming.
@code{@@defop} takes as arguments the overall name of the category of
operation, the name of the class of the operation, the name of the
operation, and its arguments, if any.  @xref{Definition
Commands}, and @ref{deffnx,, Def Cmds in Detail}.

@item @@defopt @var{option-name}
@itemx @@defoptx @var{option-name}
Format a description for a user option.  The command is equivalent to
@samp{@@defvr @{User Option@} @dots{}}.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@defspec @var{special-form-name} @var{arguments}@dots{}
@itemx @@defspecx @var{special-form-name} @var{arguments}@dots{}
Format a description for a special form.  The command is equivalent to
@samp{@@deffn @{Special Form@} @dots{}}.  @xref{Definition Commands},
and @ref{deffnx,, Def Cmds in Detail}.

@item @@deftp @var{category} @var{name-of-type} @var{attributes}@dots{}
@itemx @@deftpx @var{category} @var{name-of-type} @var{attributes}@dots{}
Format a description for a data type.  @code{@@deftp} takes as arguments
the category, the name of the type (which is a word like @samp{int} or
@samp{float}), and then the names of attributes of objects of that type.
@xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}.

@item @@deftypefn @var{classification} @var{data-type} @var{name} @var{arguments}@dots{}
@itemx @@deftypefnx @var{classification} @var{data-type} @var{name} @var{arguments}@dots{}
Format a description for a function or similar entity that may take
arguments and that is typed.  @code{@@deftypefn} takes as arguments the
classification of entity being described, the type, the name of the
entity, and its arguments, if any.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@deftypefun @var{data-type} @var{function-name} @var{arguments}@dots{}
@itemx @@deftypefunx @var{data-type} @var{function-name} @var{arguments}@dots{}
Format a description for a function in a typed language.
The command is equivalent to @samp{@@deftypefn Function @dots{}}.
@xref{Definition Commands},
and @ref{deffnx,, Def Cmds in Detail}.

@item @@deftypevr @var{classification} @var{data-type} @var{name}
@itemx @@deftypevrx @var{classification} @var{data-type} @var{name}
Format a description for something like a variable in a typed
language---an entity that records a value.  Takes as arguments the
classification of entity being described, the type, and the name of the
entity.  @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in
Detail}.

@item @@deftypevar @var{data-type} @var{variable-name}
@itemx @@deftypevarx @var{data-type} @var{variable-name}
Format a description for a variable in a typed language.  The command is
equivalent to @samp{@@deftypevr Variable @dots{}}.  @xref{Definition
Commands}, and @ref{deffnx,, Def Cmds in Detail}.

@item @@defun @var{function-name} @var{arguments}@dots{}
@itemx @@defunx @var{function-name} @var{arguments}@dots{}
Format a description for functions.  The command is equivalent to
@samp{@@deffn Function @dots{}}.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@defvar @var{variable-name}
@itemx @@defvarx @var{variable-name}
Format a description for variables.  The command is equivalent to
@samp{@@defvr Variable @dots{}}.  @xref{Definition Commands}, and
@ref{deffnx,, Def Cmds in Detail}.

@item @@defvr @var{category} @var{name}
@itemx @@defvrx @var{category} @var{name}
Format a description for any kind of variable.  @code{@@defvr} takes
as arguments the category of the entity and the name of the entity.
@xref{Definition Commands},
and @ref{deffnx,, Def Cmds in Detail}.

@item @@detailmenu@{@}
Use to avoid Makeinfo confusion stemming from the detailed node listing
in a master menu.  @xref{Master Menu Parts}.

@item @@dfn@{@var{term}@}
Highlight the introductory or defining use of a term.
@xref{dfn, , @code{@@dfn}}.@refill

@item @@dircategory @var{dirpart}
Specify a part of the Info directory menu where this file's entry should
go.  @xref{Installing Dir Entries}.

@item @@direntry
Begin the Info directory menu entry for this file.
@xref{Installing Dir Entries}.

@need 100
@item @@display
Begin a kind of example.  Indent text, do not fill, do not select a
new font.  Pair with @code{@@end display}.  @xref{display, ,
@code{@@display}}.@refill

@item @@dmn@{@var{dimension}@}
Format a unit of measure, as in 12@dmn{pt}.  Causes @TeX{} to insert a
thin space before @var{dimension}.  No effect in Info.
@xref{dmn, , @code{@@dmn}}.@refill

@need 100
@item @@dots@{@}
Insert an ellipsis: @samp{@dots{}}.
@xref{dots, , @code{@@dots}}.@refill

@item @@email@{@var{address}@}
Indicate an electronic mail address.
@xref{email, , @code{@@email}}.@refill

@need 100
@item @@emph@{@var{text}@}
Highlight @var{text}; text is displayed in @emph{italics} in printed
output, and surrounded by asterisks in Info.  @xref{Emphasis, , Emphasizing Text}.@refill

@item @@end @var{environment}
Ends @var{environment}, as in @samp{@@end example}.  @xref{Formatting
Commands,,@@-commands}.

@item @@enddots@{@}
Generate an end-of-sentence of ellipsis, like this @enddots{}
@xref{dots,,@code{@@dots@{@}}}.

@need 100
@item @@enumerate [@var{number-or-letter}]
Begin a numbered list, using @code{@@item} for each entry.
Optionally, start list with @var{number-or-letter}.  Pair with
@code{@@end enumerate}.  @xref{enumerate, ,
@code{@@enumerate}}.@refill

@need 100
@item @@equiv@{@}
Indicate to the reader the exact equivalence of two forms with a
glyph: @samp{@equiv{}}.  @xref{Equivalence}.@refill

@item @@error@{@}
Indicate to the reader with a glyph that the following text is
an error message: @samp{@error{}}.  @xref{Error Glyph}.@refill

@item @@evenfooting [@var{left}] @@| [@var{center}] @@| [@var{right}]
Specify page footings for even-numbered (left-hand) pages.  Not relevant to
Info.  @xref{Custom Headings, , How to Make Your Own Headings}.@refill

@item @@evenheading [@var{left}] @@| [@var{center}] @@| [@var{right}]
Specify page headings for even-numbered (left-hand) pages.  Only
supported within @code{@@iftex}.  @xref{Custom Headings, , How to Make
Your Own Headings}.@refill

@item @@everyfooting [@var{left}] @@| [@var{center}] @@| [@var{right}]
@itemx @@everyheading [@var{left}] @@| [@var{center}] @@| [@var{right}]
Specify page footings resp.@: headings for every page.  Not relevant to
Info.  @xref{Custom Headings, , How to Make Your Own Headings}.@refill

@item @@example
Begin an example.  Indent text, do not fill, and select fixed-width font.
Pair with @code{@@end example}.  @xref{example, ,
@code{@@example}}.@refill

@item @@exclamdown@{@}
Generate an upside-down exclamation point.  @xref{Inserting Accents}.

@item @@exdent @var{line-of-text}
Remove any indentation a line might have.  @xref{exdent, ,
Undoing the Indentation of a Line}.@refill

@item @@expansion@{@}
Indicate the result of a macro expansion to the reader with a special
glyph: @samp{@expansion{}}.
@xref{expansion, , @expansion{} Indicating an Expansion}.@refill

@item @@file@{@var{filename}@}
Highlight the name of a file, buffer, node, or directory.  @xref{file, ,
@code{@@file}}.@refill

@item @@finalout
Prevent @TeX{} from printing large black warning rectangles beside
over-wide lines.  @xref{Overfull hboxes}.@refill

@need 100
@item @@findex @var{entry}
Add @var{entry} to the index of functions.  @xref{Index Entries, ,
Defining the Entries of an Index}.@refill

@need 200
@item @@flushleft
@itemx @@flushright
Left justify every line but leave the right end ragged.
Leave font as is.  Pair with @code{@@end flushleft}.
@code{@@flushright} analogous.
@xref{flushleft & flushright, , @code{@@flushleft} and
@code{@@flushright}}.@refill

@need 200
@item @@footnote@{@var{text-of-footnote}@}
Enter a footnote.  Footnote text is printed at the bottom of the page
by @TeX{}; Info may format in either `End' node or `Separate' node style.
@xref{Footnotes}.@refill

@item @@footnotestyle @var{style}
Specify an Info file's footnote style, either @samp{end} for the end
node style or @samp{separate} for the separate node style.
@xref{Footnotes}.@refill

@item @@format
Begin a kind of example.  Like @code{@@example} or @code{@@display},
but do not narrow the margins and do not select the fixed-width font.
Pair with @code{@@end format}.  @xref{example, ,
@code{@@example}}.@refill

@item @@ftable @var{formatting-command}
Begin a two-column table, using @code{@@item} for each entry.
Automatically enter each of the items in the first column into the
index of functions.  Pair with @code{@@end ftable}.  The same as
@code{@@table}, except for indexing.  @xref{ftable vtable, ,
@code{@@ftable} and @code{@@vtable}}.@refill

@item @@group
Hold text together that must appear on one printed page.  Pair with
@code{@@end group}.  Not relevant to Info.  @xref{group, ,
@code{@@group}}.@refill

@item @@H@{@var{c}@}
Generate the long Hungarian umlaut accent over @var{c}, as in @H{o}.

@item @@heading @var{title}
Print an unnumbered section-like heading in the text, but not in the
table of contents of a printed manual.  In Info, the title is
underlined with equal signs.  @xref{unnumberedsec appendixsec heading,
, Section Commands}.@refill

@item @@headings @var{on-off-single-double}
Turn page headings on or off, and/or specify single-sided or double-sided
page headings for printing.  @xref{headings on off, , The
@code{@@headings} Command}.

@item @@i@{@var{text}@}
Print @var{text} in @i{italic} font.  No effect in Info.
@xref{Fonts}.@refill

@item @@ifclear @var{flag}
If @var{flag} is cleared, the Texinfo formatting commands format text
between @code{@@ifclear @var{flag}} and the following @code{@@end
ifclear} command.
@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill

@item @@ifhtml
@itemx @@ifinfo
Begin a stretch of text that will be ignored by @TeX{} when it typesets
the printed manual.  The text appears only in the HTML resp.@: Info
file.  Pair with @code{@@end ifhtml} resp.@: @code{@@end ifinfo}.
@xref{Conditionals, , Conditionally Visible Text}.@refill

@item @@ifset @var{flag}
If @var{flag} is set, the Texinfo formatting commands format text
between @code{@@ifset @var{flag}} and the following @code{@@end ifset}
command.
@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill

@item @@iftex
Begin a stretch of text that will not appear in the Info file, but
will be processed only by @TeX{}.  Pair with @code{@@end iftex}.
@xref{Conditionals, , Conditionally Visible Text}.@refill

@item @@ignore
Begin a stretch of text that will not appear in either the Info file
or the printed output.  Pair with @code{@@end ignore}.
@xref{Comments, , Comments and Ignored Text}.@refill

@item @@include @var{filename}
Incorporate the contents of the file @var{filename} into the Info file
or printed document.  @xref{Include Files}.@refill

@item @@inforef@{@var{node-name}, [@var{entry-name}], @var{info-file-name}@}
Make a cross reference to an Info file for which there is no printed
manual.  @xref{inforef, , Cross references using
@code{@@inforef}}.@refill

@item \input @var{macro-definitions-file}
Use the specified macro definitions file.  This command is used only
in the first line of a Texinfo file to cause @TeX{} to make use of the
@file{texinfo} macro definitions file.  The backslash in @code{\input}
is used instead of an @code{@@} because @TeX{} does not
recognize @code{@@} until after it has read the definitions file.
@xref{Header, , The Texinfo File Header}.@refill

@item @@item
Indicate the beginning of a marked paragraph for @code{@@itemize} and
@code{@@enumerate}; indicate the beginning of the text of a first column
entry for @code{@@table}, @code{@@ftable}, and @code{@@vtable}.
@xref{Lists and Tables}.@refill

@item @@itemize  @var{mark-generating-character-or-command}
Produce a sequence of indented paragraphs, with a mark inside the left
margin at the beginning of each paragraph.  Pair with @code{@@end
itemize}.  @xref{itemize, , @code{@@itemize}}.@refill

@item @@itemx
Like @code{@@item} but do not generate extra vertical space above the
item text.  @xref{itemx, , @code{@@itemx}}.@refill

@item @@kbd@{@var{keyboard-characters}@}
Indicate text that is characters of input to be typed by
users.  @xref{kbd, , @code{@@kbd}}.@refill

@item @@key@{@var{key-name}@}
Highlight @var{key-name}, a name for a key on a keyboard.
@xref{key, , @code{@@key}}.@refill

@item @@kindex @var{entry}
Add @var{entry} to the index of keys.  @xref{Index Entries, , Defining the
Entries of an Index}.@refill

@item @@L@{@}
@itemx @@l@{@}
Generate the uppercase and lowercase Polish suppressed-L letters,
respectively: @L{}, @l{}.

@c Possibly this can be tossed now that we have macros.  --karl, 16sep96.
@item @@global@@let@var{new-command}=@var{existing-command}
Equate a new highlighting command with an existing one.  Only for
@TeX{}.  Write definition inside of @code{@@iftex} @dots{} @code{@@end
iftex}. @xref{Customized Highlighting}.@refill

@item @@lisp
Begin an example of Lisp code.  Indent text, do not fill, and select
fixed-width font.  Pair with @code{@@end lisp}.  @xref{Lisp Example, ,
@code{@@lisp}}.@refill

@item @@lowersections
Change subsequent chapters to sections, sections to subsections, and so
on. @xref{Raise/lower sections, , @code{@@raisesections} and
@code{@@lowersections}}.@refill

@item @@macro @var{macro-name} @{@var{params}@}
Define a new Texinfo command @code{@@@var{macro-name}@{@var{params}@}}.
Only supported by Makeinfo and Texi2dvi.  @xref{Defining Macros}.

@item @@majorheading @var{title}
Print a chapter-like heading in the text, but not in the table of
contents of a printed manual.  Generate more vertical whitespace before
the heading than the @code{@@chapheading} command.  In Info, the chapter
heading line is underlined with asterisks.  @xref{majorheading &
chapheading, , @code{@@majorheading} and @code{@@chapheading}}.@refill

@item @@math@{@var{mathematical-expression}@}
Format a mathematical expression.
@xref{math, , @code{@@math}: Inserting Mathematical Expressions}.

@item @@menu
Mark the beginning of a menu of nodes in Info.  No effect in a printed
manual.  Pair with @code{@@end menu}.  @xref{Menus}.@refill

@item @@minus@{@}
Generate a minus sign, `@minus{}'.  @xref{minus, , @code{@@minus}}.@refill

@item @@multitable @var{column-width-spec}
Begin a multi-column table.  Pair with @code{@@end multitable}.
@xref{Multitable Column Widths}.

@item @@need @var{n}
Start a new page in a printed manual if fewer than @var{n} mils
(thousandths of an inch) remain on the current page.  @xref{need, ,
@code{@@need}}.@refill

@item @@node @var{name, next, previous, up}
Define the beginning of a new node in Info, and serve as a locator for
references for @TeX{}.  @xref{node, , @code{@@node}}.@refill

@item @@noindent
Prevent text from being indented as if it were a new paragraph.
@xref{noindent, , @code{@@noindent}}.@refill

@item @@O@{@}
@itemx @@o@{@}
Generate the uppercase and lowercase Owith-slash letters, respectively:
@O{}, @o{}.

@item @@oddfooting [@var{left}] @@| [@var{center}] @@| [@var{right}]
@itemx @@oddheading [@var{left}] @@| [@var{center}] @@| [@var{right}]
Specify page footings resp.@: headings for odd-numbered (right-hand)
pages.  Only allowed inside @code{@@iftex}.  @xref{Custom Headings, ,
How to Make Your Own Headings}.@refill

@item @@OE@{@}
@itemx @@oe@{@}
Generate the uppercase and lowercase OE ligatures, respectively:
@OE{}, @oe{}.  @xref{Inserting Accents}.

@item @@page
Start a new page in a printed manual.  No effect in Info.
@xref{page, , @code{@@page}}.@refill

@item @@paragraphindent @var{indent}
Indent paragraphs by @var{indent} number of spaces; delete indentation
if the value of @var{indent} is 0; and do not change indentation if
@var{indent} is @code{asis}. @xref{paragraphindent, , Paragraph
Indenting}.@refill

@item @@pindex @var{entry}
Add @var{entry} to the index of programs.  @xref{Index Entries, , Defining
the Entries of an Index}.@refill

@item @@point@{@}
Indicate the position of point in a buffer to the reader with a
glyph: @samp{@point{}}.  @xref{Point Glyph, , Indicating
Point in a Buffer}.@refill

@item @@pounds@{@}
Generate the pounds sterling currency sign.
@xref{pounds,,@code{@@pounds@{@}}}.

@item @@print@{@}
Indicate printed output to the reader with a glyph:
@samp{@print{}}.  @xref{Print Glyph}.@refill

@item @@printindex @var{index-name}
Print an alphabetized two-column index in a printed manual or generate
an alphabetized menu of index entries for Info.  @xref{Printing
Indices & Menus}.@refill

@item @@pxref@{@var{node-name}, [@var{entry}], [@var{topic-or-title}], [@var{info-file}], [@var{manual}]@}
Make a reference that starts with a lower case `see' in a printed
manual.  Use within parentheses only.  Do not follow command with a
punctuation mark---the Info formatting commands automatically insert
terminating punctuation as needed.  Only the first argument is mandatory.
@xref{pxref, , @code{@@pxref}}.@refill

@item @@questiondown@{@}
Generate an upside-down question mark.  @xref{Inserting Accents}.

@item @@quotation
Narrow the margins to indicate text that is quoted from another real
or imaginary work.  Write command on a line of its own.  Pair with
@code{@@end quotation}.  @xref{quotation, ,
@code{@@quotation}}.@refill

@need 100
@item @@r@{@var{text}@}
Print @var{text} in @r{roman} font.  No effect in Info.
@xref{Fonts}.@refill

@item @@raisesections
Change subsequent sections to chapters, subsections to sections, and so
on.  @xref{Raise/lower sections, , @code{@@raisesections} and
@code{@@lowersections}}.@refill

@need 300
@item @@ref@{@var{node-name}, [@var{entry}], [@var{topic-or-title}], [@var{info-file}], [@var{manual}]@}
Make a reference.  In a printed manual, the reference does not start
with a `See'.  Follow command with a punctuation mark.  Only the first
argument is mandatory.  @xref{ref, , @code{@@ref}}.@refill

@need 300
@item @@refill
In Info, refill and indent the paragraph after all the other processing
has been done.  No effect on @TeX{}, which always refills.  This command
is no longer needed, since all formatters now automatically refill.
@xref{Refilling Paragraphs}.@refill

@need 300
@item @@result@{@}
Indicate the result of an expression to the reader with a special
glyph: @samp{@result{}}.  @xref{result, , @code{@@result}}.@refill

@item @@ringaccent@{@var{c}@}
Generate a ring accent over the next character, as in @ringaccent{o}.
@xref{Inserting Accents}.

@item @@samp@{@var{text}@}
Highlight @var{text} that is a literal example of a sequence of
characters.  Used for single characters, for statements, and often for
entire shell commands.  @xref{samp, , @code{@@samp}}.@refill

@item @@sc@{@var{text}@}
Set @var{text} in a printed output in @sc{the small caps font} and
set text in the Info file in uppercase letters.
@xref{Smallcaps}.@refill

@item @@section @var{title}
Begin a section within a chapter.  In a printed manual, the section
title is numbered and appears in the table of contents.  In Info, the
title is underlined with equal signs.  @xref{section, ,
@code{@@section}}.@refill

@item @@set @var{flag} [@var{string}]
Make @var{flag} active, causing the Texinfo formatting commands to
format text between subsequent pairs of @code{@@ifset @var{flag}} and
@code{@@end ifset} commands.  Optionally, set value of @var{flag} to
@var{string}.
@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill

@item @@setchapternewpage @var{on-off-odd}
Specify whether chapters start on new pages, and if so, whether on
odd-numbered (right-hand) new pages.  @xref{setchapternewpage, ,
@code{@@setchapternewpage}}.@refill

@item @@setfilename @var{info-file-name}
Provide a name to be used by the Info file.  This command is essential
for @TeX{} formatting as well, even though it produces no output.
@xref{setfilename, , @code{@@setfilename}}.@refill

@item @@settitle @var{title}
Provide a title for page headers in a printed manual.
@xref{settitle, , @code{@@settitle}}.@refill

@item @@shortcontents
Print a short table of contents.  Not relevant to Info, which uses
menus rather than tables of contents.  A synonym for
@code{@@summarycontents}.  @xref{Contents, , Generating a Table of
Contents}.@refill

@item @@shorttitlepage@{@var{title}@}
Generate a minimal title page.  @xref{titlepage,,@code{@@titlepage}}.

@need 400
@item @@smallbook
Cause @TeX{} to produce a printed manual in a 7 by 9.25 inch format
rather than the regular 8.5 by 11 inch format.  @xref{smallbook, ,
Printing Small Books}.  Also, see @ref{smallexample & smalllisp, ,
@code{@@smallexample} and @code{@@smalllisp}}.@refill

@need 400
@item @@smallexample
Indent text to indicate an example.  Do not fill, select fixed-width
font.  In @code{@@smallbook} format, print text in a smaller font than
with @code{@@example}.  Pair with @code{@@end smallexample}.
@xref{smallexample & smalllisp, , @code{@@smallexample} and
@code{@@smalllisp}}.@refill

@need 400
@item @@smalllisp
Begin an example of Lisp code.  Indent text, do not fill, select
fixed-width font.  In @code{@@smallbook} format, print text in a
smaller font.  Pair with @code{@@end smalllisp}.  @xref{smallexample &
smalllisp, , @code{@@smallexample} and @code{@@smalllisp}}.@refill

@need 700
@item @@sp @var{n}
Skip @var{n} blank lines.  @xref{sp, , @code{@@sp}}.@refill

@item @@ss@{@}
Generate the German sharp-S es-zet letter, @ss{}.  @xref{Inserting Accents}.

@need 700
@item @@strong @var{text}
Emphasize @var{text} by typesetting it in a @strong{bold} font for the
printed manual and by surrounding it with asterisks for Info.
@xref{emph & strong, , Emphasizing Text}.@refill

@item @@subheading @var{title}
Print an unnumbered subsection-like heading in the text, but not in
the table of contents of a printed manual.  In Info, the title is
underlined with hyphens.  @xref{unnumberedsubsec appendixsubsec
subheading, , @code{@@unnumberedsubsec} @code{@@appendixsubsec}
@code{@@subheading}}.@refill

@item @@subsection @var{title}
Begin a subsection within a section.  In a printed manual, the
subsection title is numbered and appears in the table of contents.  In
Info, the title is underlined with hyphens.  @xref{subsection, ,
@code{@@subsection}}.@refill

@item @@subsubheading @var{title}
Print an unnumbered subsubsection-like heading in the text, but not in
the table of contents of a printed manual.  In Info, the title is
underlined with periods.  @xref{subsubsection, , The `subsub'
Commands}.@refill

@item @@subsubsection @var{title}
Begin a subsubsection within a subsection.  In a printed manual,
the subsubsection title is numbered and appears in the table of
contents.  In Info, the title is underlined with periods.
@xref{subsubsection, , The `subsub' Commands}.@refill

@item @@subtitle @var{title}
In a printed manual, set a subtitle in a normal sized font flush to
the right-hand side of the page.  Not relevant to Info, which does not
have title pages.  @xref{title subtitle author, , @code{@@title}
@code{@@subtitle} and @code{@@author} Commands}.@refill

@item @@summarycontents
Print a short table of contents.  Not relevant to Info, which uses
menus rather than tables of contents.  A synonym for
@code{@@shortcontents}.  @xref{Contents, , Generating a Table of
Contents}.@refill

@need 300
@item @@syncodeindex @var{from-index} @var{into-index}
Merge the index named in the first argument into the index named in
the second argument, printing the entries from the first index in
@code{@@code} font.  @xref{Combining Indices}.@refill

@need 300
@item @@synindex @var{from-index} @var{into-index}
Merge the index named in the first argument into the index named in
the second argument.  Do not change the font of @var{from-index}
entries.  @xref{Combining Indices}.@refill

@need 100
@item @@t@{@var{text}@}
Print @var{text} in a @t{fixed-width}, typewriter-like font.
No effect in Info.  @xref{Fonts}.@refill

@item @@tab
Separate columns in a multitable.  @xref{Multitable Rows}.

@need 400
@item @@table @var{formatting-command}
Begin a two-column table, using @code{@@item} for each entry.  Write
each first column entry on the same line as @code{@@item}.  First
column entries are printed in the font resulting from
@var{formatting-command}.  Pair with @code{@@end table}.
@xref{Two-column Tables, , Making a Two-column Table}.
Also see @ref{ftable vtable, , @code{@@ftable} and @code{@@vtable}},
and @ref{itemx, , @code{@@itemx}}.@refill

@item @@TeX@{@}
Insert the logo @TeX{}.  @xref{TeX and copyright, , Inserting @TeX{}
and @copyright{}}.@refill

@item @@tex
Enter @TeX{} completely.  Pair with @code{@@end tex}.  @xref{Using
Ordinary TeX Commands, , Using Ordinary @TeX{} Commands}.@refill

@item @@thischapter
@itemx @@thischaptername
@itemx @@thisfile
@itemx @@thispage
@itemx @@thistitle
Only allowed in a heading or footing.  Stands for the number and name of
the current chapter (in the format `Chapter 1: Title'), the chapter name
only, the filename, the current page number, and the title of the
document, respectively.  @xref{Custom Headings, , How to Make Your Own
Headings}.@refill

@item @@tindex @var{entry}
Add @var{entry} to the index of data types.  @xref{Index Entries, ,
Defining the Entries of an Index}.@refill

@item @@title @var{title}
In a printed manual, set a title flush to the left-hand side of the
page in a larger than normal font and underline it with a black rule.
Not relevant to Info, which does not have title pages.  @xref{title
subtitle author, , The @code{@@title} @code{@@subtitle} and
@code{@@author} Commands}.@refill

@need 400
@item @@titlefont@{@var{text}@}
In a printed manual, print @var{text} in a larger than normal font.
Not relevant to Info, which does not have title pages.
@xref{titlefont center sp, , The @code{@@titlefont} @code{@@center}
and @code{@@sp} Commands}.@refill

@need 300
@item @@titlepage
Indicate to Texinfo the beginning of the title page.  Write command on
a line of its own.  Pair with @code{@@end titlepage}.  Nothing between
@code{@@titlepage} and @code{@@end titlepage} appears in Info.
@xref{titlepage, , @code{@@titlepage}}.@refill

@need 150
@item @@today@{@}
Insert the current date, in `1 Jan 1900' style.  @xref{Custom
Headings, , How to Make Your Own Headings}.@refill

@item @@top @var{title}
In a Texinfo file to be formatted with @code{makeinfo}, identify the
topmost @code{@@node} line in the file, which must be written on the line
immediately preceding the @code{@@top} command.  Used for
@code{makeinfo}'s node pointer insertion feature.  The title is
underlined with asterisks.  Both the @code{@@node} line and the @code{@@top}
line normally should be enclosed by @code{@@ifinfo} and @code{@@end
ifinfo}.  In @TeX{} and @code{texinfo-format-buffer}, the @code{@@top}
command is merely a synonym for @code{@@unnumbered}.  @xref{makeinfo
Pointer Creation, , Creating Pointers with @code{makeinfo}}.

@item @@u@var{c}
@itemx @@ubaraccent@var{c}
@itemx @@udotaccent@var{c}
Generate a breve, underbar, or underdot accent, respectively, over or
under the character @var{c}, as in @u{o}, @ubaraccent{o},
@udotaccent{o}.  @xref{Inserting Accents}.

@item @@unnumbered @var{title}
In a printed manual, begin a chapter that appears without chapter
numbers of any kind.  The title appears in the table of contents of a
printed manual.  In Info, the title is underlined with asterisks.
@xref{unnumbered & appendix, , @code{@@unnumbered} and
@code{@@appendix}}.@refill

@item @@unnumberedsec @var{title}
In a printed manual, begin a section that appears without section
numbers of any kind.  The title appears in the table of contents of a
printed manual.  In Info, the title is underlined with equal signs.
@xref{unnumberedsec appendixsec heading, , Section Commands}.@refill

@item @@unnumberedsubsec @var{title}
In a printed manual, begin an unnumbered subsection within a
chapter.  The title appears in the table of contents of a printed
manual.  In Info, the title is underlined with hyphens.
@xref{unnumberedsubsec appendixsubsec subheading, ,
@code{@@unnumberedsubsec} @code{@@appendixsubsec}
@code{@@subheading}}.@refill

@item @@unnumberedsubsubsec @var{title}
In a printed manual, begin an unnumbered subsubsection within a
chapter.  The title appears in the table of contents of a printed
manual.  In Info, the title is underlined with periods.
@xref{subsubsection, , The `subsub' Commands}.@refill

@item @@url@{@var{url}@}
Highlight text that is a uniform resource locator for the World Wide
Web.  @xref{url, , @code{@@url}}.@refill

@item @@v@var{c}
Generate check accent over the character @var{c}, as in @v{o}.
@xref{Inserting Accents}.

@item @@value@{@var{flag}@}
Replace @var{flag} with the value to which it is set by @code{@@set
@var{flag}}.
@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill

@item @@var@{@var{metasyntactic-variable}@}
Highlight a metasyntactic variable, which is something that stands for
another piece of text.  @xref{var, , Indicating Metasyntactic
Variables}.@refill

@need 400
@item @@vindex @var{entry}
Add @var{entry} to the index of variables.  @xref{Index Entries, ,
Defining the Entries of an Index}.@refill

@need 400
@item @@vskip @var{amount}
In a printed manual, insert whitespace so as to push text on the
remainder of the page towards the bottom of the page.  Used in
formatting the copyright page with the argument @samp{0pt plus
1filll}.  (Note spelling of @samp{filll}.)  @code{@@vskip} may be used
only in contexts ignored for Info.  @xref{Copyright & Permissions, ,
The Copyright Page and Printed Permissions}.@refill

@need 400
@item @@vtable @var{formatting-command}
Begin a two-column table, using @code{@@item} for each entry.
Automatically enter each of the items in the first column into the
index of variables.  Pair with @code{@@end vtable}.  The same as
@code{@@table}, except for indexing.  @xref{ftable vtable, ,
@code{@@ftable} and @code{@@vtable}}.@refill

@need 400
@item @@w@{@var{text}@}
Prevent @var{text} from being split across two lines.  Do not end a
paragraph that uses @code{@@w} with an @code{@@refill} command.
@xref{w, , @code{@@w}}.@refill

@need 400
@item @@xref@{@var{node-name}, [@var{entry}], [@var{topic-or-title}], [@var{info-file}], [@var{manual}]@}
Make a reference that starts with `See' in a printed manual.  Follow
command with a punctuation mark.  Only the first argument is
mandatory.  @xref{xref, , @code{@@xref}}.@refill
@end table

@node Tips, Sample Texinfo File, Command List, Top
@comment  node-name,  next,  previous,  up
@appendix Tips and Hints

Here are some tips for writing Texinfo documentation:@refill

@cindex Tips
@cindex Usage tips
@cindex Hints
@itemize @bullet
@item
Write in the present tense, not in the past or the future.

@item
Write actively!  For example, write ``We recommend that @dots{}'' rather
than ``It is recommended that @dots{}''.

@item
Use 70 or 72 as your fill column.  Longer lines are hard to read.

@item
Include a copyright notice and copying permissions.
@end itemize

@subsubheading Index, index, index!

Write many index entries, in different ways.
Readers like indices; they are helpful and convenient.

Although it is easiest to write index entries as you write the body of
the text, some people prefer to write entries afterwards.  In either
case, write an entry before the paragraph to which it applies.  This
way, an index entry points to the first page of a paragraph that is
split across pages.

Here are more hints we have found valuable:

@itemize @bullet
@item
Write each index entry differently, so each entry refers to a different
place in the document.

@item
Write index entries only where a topic is discussed significantly.  For
example, it is not useful to index ``debugging information'' in a
chapter on reporting bugs.  Someone who wants to know about debugging
information will certainly not find it in that chapter.

@item
Consistently capitalize the first word of every concept index entry,
or else consistently use lower case.  Terse entries often call for
lower case; longer entries for capitalization.  Whichever case
convention you use, please use one or the other consistently!  Mixing
the two styles looks bad.

@item
Always capitalize or use upper case for those words in an index for
which this is proper, such as names of countries or acronyms.  Always
use the appropriate case for case-sensitive names, such as those in C or
Lisp.

@item
Write the indexing commands that refer to a whole section immediately
after the section command, and write the indexing commands that refer to
the paragraph before the paragraph.

@need 1000
In the example that follows, a blank line comes after the index
entry for ``Leaping'':

@example
@group
@@section The Dog and the Fox
@@cindex Jumping, in general
@@cindex Leaping

@@cindex Dog, lazy, jumped over
@@cindex Lazy dog jumped over
@@cindex Fox, jumps over dog
@@cindex Quick fox jumps over dog
The quick brown fox jumps over the lazy dog.
@end group
@end example

@noindent
(Note that the example shows entries for the same concept that are
written in different ways---@samp{Lazy dog}, and @samp{Dog, lazy}---so
readers can look up the concept in different ways.)
@end itemize

@subsubheading Blank lines

@itemize @bullet
@item
Insert a blank line between a sectioning command and the first following
sentence or paragraph, or between the indexing commands associated with
the sectioning command and the first following sentence or paragraph, as
shown in the tip on indexing.  Otherwise, a formatter may fold title and
paragraph together.

@item
Always insert a blank line before an @code{@@table} command and after an
@code{@@end table} command; but never insert a blank line after an
@code{@@table} command or before an @code{@@end table} command.

@need 1000
For example,

@example
@group
Types of fox:

@@table @@samp
@@item Quick
Jump over lazy dogs.
@end group

@group
@@item Brown
Also jump over lazy dogs.
@@end table

@end group
@group
@@noindent
On the other hand, @dots{}
@end group
@end example

Insert blank lines before and after @code{@@itemize} @dots{} @code{@@end
itemize} and @code{@@enumerate} @dots{} @code{@@end enumerate} in the
same way.
@end itemize

@subsubheading Complete phrases

Complete phrases are easier to read than @dots{}

@itemize @bullet
@item
Write entries in an itemized list as complete sentences; or at least, as
complete phrases.  Incomplete expressions @dots{} awkward @dots{} like
this.

@item
Write the prefatory sentence or phrase for a multi-item list or table as
a complete expression.  Do not write ``You can set:''; instead, write
``You can set these variables:''.  The former expression sounds cut off.
@end itemize

@subsubheading Editions, dates and versions

Write the edition and version numbers and date in three places in every
manual:

@enumerate
@item
In the first @code{@@ifinfo} section, for people reading the Texinfo file.

@item
In the @code{@@titlepage} section, for people reading the printed manual.

@item
In the `Top' node, for people reading the Info file.
@end enumerate

@noindent
Also, it helps to write a note before the first @code{@@ifinfo}
section to explain what you are doing.

@need 800
@noindent
For example:

@example
@group
@@c ===> NOTE! <==
@@c Specify the edition and version numbers and date
@@c in *three* places:
@@c   1. First ifinfo section  2. title page  3. top node
@@c To find the locations, search for !!set
@end group

@group
@@ifinfo
@@c !!set edition, date, version
This is Edition 4.03, January 1992,
of the @@cite@{GDB Manual@} for GDB Version 4.3.
@dots{}
@end group
@end example

@noindent
---or use @code{@@set} and @code{@@value}
(@pxref{value Example, , @code{@@value} Example}).

@subsubheading Definition Commands

Definition commands are @code{@@deffn}, @code{@@defun},
@code{@@defmac}, and the like, and enable you to write descriptions in
a uniform format.@refill

@itemize @bullet
@item
Write just one definition command for each entity you define with a
definition command.  The automatic indexing feature creates an index
entry that leads the reader to the definition.

@item
Use @code{@@table} @dots{} @code{@@end table} in an appendix that
contains a summary of functions, not @code{@@deffn} or other definition
commands.
@end itemize

@subsubheading Capitalization

@itemize @bullet
@item
Capitalize @samp{Texinfo}; it is a name.  Do not write the @samp{x} or
@samp{i} in upper case.

@item
Capitalize @samp{Info}; it is a name.

@item
Write @TeX{} using the @code{@@TeX@{@}} command.  Note the uppercase
@samp{T} and @samp{X}.  This command causes the formatters to
typeset the name according to the wishes of Donald Knuth, who wrote
@TeX{}.
@end itemize

@subsubheading Spaces

Do not use spaces to format a Texinfo file, except inside of
@code{@@example} @dots{} @code{@@end example} and similar commands.

@need 700
For example, @TeX{} fills the following:

@example
@group
    @@kbd@{C-x v@}
    @@kbd@{M-x vc-next-action@}
       Perform the next logical operation
       on the version-controlled file
       corresponding to the current buffer.
@end group
@end example

@need 950
@noindent
so it looks like this:

@iftex
@quotation
    @kbd{C-x v}
    @kbd{M-x vc-next-action}
       Perform the next logical operation on the version-controlled file
       corresponding to the current buffer.
@end quotation
@end iftex
@ifinfo
@quotation
`C-x v' `M-x vc-next-action' Perform the next logical operation on the
version-controlled file corresponding to the current buffer.
@end quotation
@end ifinfo

@noindent
In this case, the text should be formatted with
@code{@@table}, @code{@@item}, and @code{@@itemx}, to create a table.

@subsubheading @@code, @@samp, @@var, and @samp{---}

@itemize @bullet
@item
Use @code{@@code} around Lisp symbols, including command names.
For example,

@example
The main function is @@code@{vc-next-action@}, @dots{}
@end example

@item
Avoid putting letters such as @samp{s} immediately after an
@samp{@@code}.  Such letters look bad.

@item
Use @code{@@var} around meta-variables.  Do not write angle brackets
around them.

@item
Use three hyphens in a row, @samp{---}, to indicate a long dash.  @TeX{}
typesets these as a long dash and the Info formatters reduce three
hyphens to two.
@end itemize

@subsubheading Periods Outside of Quotes

Place periods and other punctuation marks @emph{outside} of quotations,
unless the punctuation is part of the quotation.  This practice goes
against publishing conventions in the United States, but enables the
reader to distinguish between the contents of the quotation and the
whole passage.

For example, you should write the following sentence with the period
outside the end quotation marks:

@example
Evidently, @samp{au} is an abbreviation for ``author''.
@end example

@noindent
since @samp{au} does @emph{not} serve as an  abbreviation for
@samp{author.} (with a period following the word).

@subsubheading Introducing New Terms

@itemize @bullet
@item
Introduce new terms so that a reader who does not know them can
understand them from context; or write a definition for the term.

For example, in the following, the terms ``check in'', ``register'' and
``delta'' are all appearing for the first time; the example sentence should be
rewritten so they are understandable.

@quotation
The major function assists you in checking in a file to your
version control system and registering successive sets of changes to
it as deltas.
@end quotation

@item
Use the @code{@@dfn} command around a word being introduced, to indicate
that the reader should not expect to know the meaning already, and
should expect to learn the meaning from this passage.
@end itemize

@subsubheading @@pxref

@c !!! maybe include this in the tips on pxref
@ignore
By the way, it is okay to use pxref with something else in front of
it within the parens, as long as the pxref is followed by the close
paren, and the material inside the parens is not part of a larger
sentence.  Also, you can use xref inside parens as part of a complete
sentence so long as you terminate the cross reference with punctuation.
@end ignore
Absolutely never use @code{@@pxref} except in the special context for
which it is designed: inside parentheses, with the closing parenthesis
following immediately after the closing brace.  One formatter
automatically inserts closing punctuation and the other does not.  This
means that the output looks right both in printed output and in an Info
file, but only when the command is used inside parentheses.

@subsubheading Invoking from a Shell

You can invoke programs such as Emacs, GCC, and GAWK from a shell.
The documentation for each program should contain a section that
describes this.  Unfortunately, if the node names and titles for these
sections are all different, readers find it hard to search for the
section.@refill

Name such sections with a phrase beginning with the word
@w{`Invoking @dots{}'}, as in `Invoking Emacs'; this way
users can find the section easily.

@subsubheading @sc{ansi c} Syntax

When you use @code{@@example} to describe a C function's calling
conventions, use the @sc{ansi c} syntax, like this:@refill

@example
void dld_init (char *@@var@{path@});
@end example

@noindent
And in the subsequent discussion, refer to the argument values by
writing the same argument names, again highlighted with
@code{@@var}.@refill

@need 800
Avoid the obsolete style that looks like this:@refill

@example
#include <dld.h>

dld_init (path)
char *path;
@end example

Also, it is best to avoid writing @code{#include} above the
declaration just to indicate that the function is declared in a
header file.  The practice may give the misimpression that the
@code{#include} belongs near the declaration of the function.  Either
state explicitly which header file holds the declaration or, better
yet, name the header file used for a group of functions at the
beginning of the section that describes the functions.@refill

@subsubheading Bad Examples

Here are several examples of bad writing to avoid:

In this example, say, `` @dots{} you must @code{@@dfn}@{check
in@} the new version.''  That flows better.

@quotation
When you are done editing the file, you must perform a
@code{@@dfn}@{check in@}.
@end quotation

In the following example, say, ``@dots{} makes a unified interface such as VC
mode possible.''

@quotation
SCCS, RCS and other version-control systems all perform similar
functions in broadly similar ways (it is this resemblance which makes
a unified control mode like this possible).
@end quotation

And in this example, you should specify what `it' refers to:

@quotation
If you are working with other people, it assists in coordinating
everyone's changes so they do not step on each other.
@end quotation

@subsubheading And Finally @dots{}

@itemize @bullet
@item
Pronounce @TeX{} as if the @samp{X} were a Greek `chi', as the last
sound in the name `Bach'.  But pronounce Texinfo as in `speck':
@samp{teckinfo}.

@item
Write notes for yourself at the very end of a Texinfo file after the
@code{@@bye}.  None of the formatters process text after the
@code{@@bye}; it is as if the text were within @code{@@ignore} @dots{}
@code{@@end ignore}.
@end itemize

@node Sample Texinfo File, Sample Permissions, Tips, Top
@comment  node-name,  next,  previous,  up
@appendix A Sample Texinfo File
@cindex Sample Texinfo file, no comments

Here is a complete, short sample Texinfo file, without any commentary.
You can see this file, with comments, in the first chapter.
@xref{Short Sample, , A Short Sample Texinfo File}.

@sp 1
@example
\input texinfo   @@c -*-texinfo-*-
@@c %**start of header
@@setfilename sample.info
@@settitle Sample Document
@@c %**end of header

@@setchapternewpage odd

@@ifinfo
This is a short example of a complete Texinfo file.

Copyright 1990 Free Software Foundation, Inc.
@@end ifinfo

@@titlepage
@@sp 10
@@comment The title is printed in a large font.
@@center @@titlefont@{Sample Title@}

@@c The following two commands start the copyright page.
@@page
@@vskip 0pt plus 1filll
Copyright @@copyright@{@} 1990 Free Software Foundation, Inc.
@@end titlepage

@@node    Top,       First Chapter, (dir),    (dir)
@@comment node-name, next,          previous, up

@@menu
* First Chapter::    The first chapter is the
                     only chapter in this sample.
* Concept Index::    This index has two entries.
@@end menu

@@node    First Chapter, Concept Index, Top,      Top
@@comment node-name,     next,          previous, up
@@chapter First Chapter
@@cindex Sample index entry

This is the contents of the first chapter.
@@cindex Another sample index entry

Here is a numbered list.

@@enumerate
@@item
This is the first item.

@@item
This is the second item.
@@end enumerate

The @@code@{makeinfo@} and @@code@{texinfo-format-buffer@}
commands transform a Texinfo file such as this into
an Info file; and @@TeX@{@} typesets it for a printed
manual.

@@node    Concept Index,    ,  First Chapter, Top
@@comment node-name,    next,  previous,      up
@@unnumbered Concept Index

@@printindex cp

@@contents
@@bye
@end example

@node Sample Permissions, Include Files, Sample Texinfo File, Top
@appendix Sample Permissions
@cindex Permissions
@cindex Copying permissions

Texinfo files should contain sections that tell the readers that they
have the right to copy and distribute the Texinfo file, the Info file,
and the printed manual.@refill

Also, if you are writing a manual about software, you should explain
that the software is free and either include the GNU General Public
License (GPL) or provide a reference to it.  @xref{Distrib, ,
Distribution, emacs, The GNU Emacs Manual}, for an example of the text
that could be used in the software ``Distribution'', ``General Public
License'', and ``NO WARRANTY'' sections of a document.  @xref{Copying,
, Texinfo Copying Conditions}, for an example of a brief explanation
of how the copying conditions provide you with rights. @refill

@menu
* Inserting Permissions::       How to put permissions in your document.
* ifinfo Permissions::          Sample @samp{ifinfo} copying permissions.
* Titlepage Permissions::       Sample Titlepage copying permissions.
@end menu

@node Inserting Permissions, ifinfo Permissions, Sample Permissions, Sample Permissions
@ifinfo
@appendixsec Inserting Permissions
@end ifinfo

In a Texinfo file, the first @code{@@ifinfo} section usually begins
with a line that says what the file documents.  This is what a person
reading the unprocessed Texinfo file or using the advanced Info
command @kbd{g *} sees first.  @inforef{Expert, Advanced Info
commands, info}, for more information. (A reader using the regular
Info commands usually starts reading at the first node and skips
this first section, which is not in a node.)@refill

In the @code{@@ifinfo} section, the summary sentence is followed by a
copyright notice and then by the copying permission notice.  One of
the copying permission paragraphs is enclosed in @code{@@ignore} and
@code{@@end ignore} commands.  This paragraph states that the Texinfo
file can be processed through @TeX{} and printed, provided the printed
manual carries the proper copying permission notice.  This paragraph
is not made part of the Info file since it is not relevant to the Info
file; but it is a mandatory part of the Texinfo file since it permits
people to process the Texinfo file in @TeX{} and print the
results.@refill

In the printed manual, the Free Software Foundation copying permission
notice follows the copyright notice and publishing information and is
located within the region delineated by the @code{@@titlepage} and
@code{@@end titlepage} commands.  The copying permission notice is exactly
the same as the notice in the @code{@@ifinfo} section except that the
paragraph enclosed in @code{@@ignore} and @code{@@end ignore} commands is
not part of the notice.@refill

To make it simple to insert a permission notice into each section of
the Texinfo file, sample permission notices for each section are
reproduced in full below.@refill

Note that you may need to specify the correct name of a section
mentioned in the permission notice.  For example, in @cite{The GDB
Manual}, the name of the section referring to the General Public
License is called the ``GDB General Public License'', but in the
sample shown below, that section is referred to generically as the
``GNU General Public License''.  If the Texinfo file does not carry a
copy of the General Public License, leave out the reference to it, but
be sure to include the rest of the sentence.@refill

@node ifinfo Permissions, Titlepage Permissions, Inserting Permissions, Sample Permissions
@comment  node-name,  next,  previous,  up
@appendixsec @samp{ifinfo} Copying Permissions
@cindex @samp{ifinfo} permissions

In the @code{@@ifinfo} section of a Texinfo file, the standard Free
Software Foundation permission notice reads as follows:@refill

@example
This file documents @dots{}

Copyright 1992 Free Software Foundation, Inc.

Permission is granted to make and distribute verbatim
copies of this manual provided the copyright notice and
this permission notice are preserved on all copies.

@@ignore
Permission is granted to process this file through TeX
and print the results, provided the printed document
carries a copying permission notice identical to this
one except for the removal of this paragraph (this
paragraph not being relevant to the printed manual).

@@end ignore
Permission is granted to copy and distribute modified
versions of this manual under the conditions for
verbatim copying, provided also that the sections
entitled ``Copying'' and ``GNU General Public License''
are included exactly as in the original, and provided
that the entire resulting derived work is distributed
under the terms of a permission notice identical to this
one.

Permission is granted to copy and distribute
translations of this manual into another language,
under the above conditions for modified versions,
except that this permission notice may be stated in a
translation approved by the Free Software Foundation.
@end example

@node Titlepage Permissions, , ifinfo Permissions, Sample Permissions
@comment  node-name,  next,  previous,  up
@appendixsec Titlepage Copying Permissions
@cindex Titlepage permissions

In the @code{@@titlepage} section of a Texinfo file, the standard Free
Software Foundation copying permission notice follows the copyright
notice and publishing information.  The standard phrasing is as
follows:@refill

@example
Permission is granted to make and distribute verbatim
copies of this manual provided the copyright notice and
this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified
versions of this manual under the conditions for
verbatim copying, provided also that the sections
entitled ``Copying'' and ``GNU General Public License''
are included exactly as in the original, and provided
that the entire resulting derived work is distributed
under the terms of a permission notice identical to this
one.

Permission is granted to copy and distribute
translations of this manual into another language,
under the above conditions for modified versions,
except that this permission notice may be stated in a
translation approved by the Free Software Foundation.
@end example

@node Include Files, Headings, Sample Permissions, Top
@comment  node-name,  next,  previous,  up
@appendix Include Files
@cindex Include files

When @TeX{} or an Info formatting command sees an @code{@@include}
command in a Texinfo file, it processes the contents of the file named
by the command and incorporates them into the @sc{dvi} or Info file being
created.  Index entries from the included file are incorporated into
the indices of the output file.@refill

Include files let you keep a single large document as a collection of
conveniently small parts.@refill

@menu
* Using Include Files::         How to use the @code{@@include} command.
* texinfo-multiple-files-update::  How to create and update nodes and
                                  menus when using included files.
* Include File Requirements::   What @code{texinfo-multiple-files-update} expects.
* Sample Include File::         A sample outer file with included files
                                  within it; and a sample included file.
* Include Files Evolution::     How use of the @code{@@include} command
                                  has changed over time.
@end menu

@node Using Include Files, texinfo-multiple-files-update, Include Files, Include Files
@appendixsec How to Use Include Files
@findex include

To include another file within a Texinfo file, write the
@code{@@include} command at the beginning of a line and follow it on
the same line by the name of a file to be included.  For
example:@refill

@example
@@include buffers.texi
@end example

An included file should simply be a segment of text that you expect to
be included as is into the overall or @dfn{outer} Texinfo file; it
should not contain the standard beginning and end parts of a Texinfo
file.  In particular, you should not start an included file with a
line saying @samp{\input texinfo}; if you do, that phrase is inserted
into the output file as is.  Likewise, you should not end an included
file with an @code{@@bye} command; nothing after @code{@@bye} is
formatted.@refill

In the past, you were required to write an @code{@@setfilename} line at the
beginning of an included file, but no longer.  Now, it does not matter
whether you write such a line.  If an @code{@@setfilename} line exists
in an included file, it is ignored.@refill

Conventionally, an included file begins with an @code{@@node} line that
is followed by an @code{@@chapter} line.  Each included file is one
chapter.  This makes it easy to use the regular node and menu creating
and updating commands to create the node pointers and menus within the
included file.  However, the simple Emacs node and menu creating and
updating commands do not work with multiple Texinfo files.  Thus you
cannot use these commands to fill in the `Next', `Previous', and `Up'
pointers of the @code{@@node} line that begins the included file.  Also,
you cannot use the regular commands to create a master menu for the
whole file.  Either you must insert the menus and the `Next',
`Previous', and `Up' pointers by hand, or you must use the GNU Emacs
Texinfo mode command, @code{texinfo-multiple-files-update}, that is
designed for @code{@@include} files.@refill

@node texinfo-multiple-files-update, Include File Requirements, Using Include Files, Include Files
@appendixsec @code{texinfo-multiple-files-update}
@findex texinfo-multiple-files-update

GNU Emacs Texinfo mode provides the @code{texinfo-multiple-files-update}
command.  This command creates or updates `Next', `Previous', and `Up'
pointers of included files as well as those in the outer or overall
Texinfo file, and it creates or updates a main menu in the outer file.
Depending whether you call it with optional arguments, the command
updates only the pointers in the first @code{@@node} line of the
included files or all of them:@refill

@table @kbd
@item M-x texinfo-multiple-files-update
Called without any arguments:@refill

@itemize @minus
@item
Create or update the `Next', `Previous', and `Up' pointers of the
first @code{@@node} line in each file included in an outer or overall
Texinfo file.@refill

@item
Create or update the `Top' level node pointers of the outer or
overall file.@refill

@item
Create or update a main menu in the outer file.@refill
@end itemize

@item C-u M-x texinfo-multiple-files-update
Called with @kbd{C-u} as a prefix argument:

@itemize @minus{}
@item
Create or update pointers in the first @code{@@node} line in each
included file.

@item
Create or update the `Top' level node pointers of the outer file.

@item
Create and insert a master menu in the outer file.  The master menu
is made from all the menus in all the included files.@refill
@end itemize

@item C-u 8 M-x texinfo-multiple-files-update
Called with a numeric prefix argument, such as @kbd{C-u 8}:

@itemize @minus
@item
Create or update @strong{all} the `Next', `Previous', and `Up' pointers
of all the included files.@refill

@item
Create or update @strong{all} the menus of all the included
files.@refill

@item
Create or update the `Top' level node pointers of the outer or
overall file.@refill

@item
And then create a master menu in the outer file.  This is similar to
invoking @code{texinfo-master-menu} with an argument when you are
working with just one file.@refill
@end itemize
@end table

Note the use of the prefix argument in interactive use: with a regular
prefix argument, just @w{@kbd{C-u}}, the
@code{texinfo-multiple-files-update} command inserts a master menu;
with a numeric prefix argument, such as @kbd{C-u 8}, the command
updates @strong{every} pointer and menu in @strong{all} the files and then inserts a
master menu.@refill

@node Include File Requirements, Sample Include File, texinfo-multiple-files-update, Include Files
@appendixsec Include File Requirements
@cindex Include file requirements
@cindex Requirements for include files

If you plan to use the @code{texinfo-multiple-files-update} command,
the outer Texinfo file that lists included files within it should
contain nothing but the beginning and end parts of a Texinfo file, and
a number of @code{@@include} commands listing the included files.  It
should not even include indices, which should be listed in an included
file of their own.@refill

Moreover, each of the included files must contain exactly one highest
level node (conventionally, @code{@@chapter} or equivalent),
and this node must be the first node in the included file.
Furthermore, each of these highest level nodes in each included file
must be at the same hierarchical level in the file structure.
Usually, each is an @code{@@chapter}, an @code{@@appendix}, or an
@code{@@unnumbered} node.  Thus, normally, each included file contains
one, and only one, chapter or equivalent-level node.@refill

The outer file should contain only @emph{one} node, the `Top' node.  It
should @emph{not} contain any nodes besides the single `Top' node.  The
@code{texinfo-multiple-files-update} command will not process
them.@refill

@node Sample Include File, Include Files Evolution, Include File Requirements, Include Files
@appendixsec Sample File with @code{@@include}
@cindex Sample @code{@@include} file
@cindex Include file sample
@cindex @code{@@include} file sample

Here is an example of a complete outer Texinfo file with @code{@@include} files
within it before running @code{texinfo-multiple-files-update}, which
would insert a main or master menu:@refill

@example
@group
\input texinfo @@c -*-texinfo-*-
@c %**start of header
@@setfilename  include-example.info
@@settitle Include Example
@c %**end of header
@end group

@group
@@setchapternewpage odd
@@titlepage
@@sp 12
@@center @@titlefont@{Include Example@}
@@sp 2
@@center by Whom Ever
@end group

@group
@@page
@@vskip 0pt plus 1filll
Copyright @@copyright@{@} 1990 Free Software Foundation, Inc.
@@end titlepage
@end group

@group
@@ifinfo
@@node Top, First, (dir), (dir)
@@top Master Menu
@@end ifinfo
@end group

@group
@@include foo.texinfo
@@include bar.texinfo
@@include concept-index.texinfo
@end group

@group
@@summarycontents
@@contents

@@bye
@end group
@end example

An included file, such as @file{foo.texinfo}, might look like
this:@refill

@example
@group
@@node First, Second, , Top
@@chapter First Chapter

Contents of first chapter @dots{}
@end group
@end example

The full contents of @file{concept-index.texinfo} might be as simple as this:

@example
@group
@@node Concept Index, , Second, Top
@@unnumbered Concept Index

@@printindex cp
@end group
@end example

The outer Texinfo source file for @cite{The GNU Emacs Lisp Reference
Manual} is named @file{elisp.texi}.  This outer file contains a master
menu with 417 entries and a list of 41 @code{@@include}
files.@refill

@node Include Files Evolution, , Sample Include File, Include Files
@comment  node-name,  next,  previous,  up
@appendixsec Evolution of Include Files

When Info was first created, it was customary to create many small
Info files on one subject.  Each Info file was formatted from its own
Texinfo source file.  This custom meant that Emacs did not need to
make a large buffer to hold the whole of a large Info file when
someone wanted information; instead, Emacs allocated just enough
memory for the small Info file that contained the particular
information sought.  This way, Emacs could avoid wasting memory.@refill

References from one file to another were made by referring to the file
name as well as the node name. (@xref{Other Info Files, , Referring to
Other Info Files}.  Also, see @ref{Four and Five Arguments, ,
@code{@@xref} with Four and Five Arguments}.)@refill

Include files were designed primarily as a way to create a single,
large printed manual out of several smaller Info files.  In a printed
manual, all the references were within the same document, so @TeX{}
could automatically determine the references' page numbers.  The Info
formatting commands used include files only for creating joint
indices; each of the individual Texinfo files had to be formatted for
Info individually.  (Each, therefore, required its own
@code{@@setfilename} line.)@refill

However, because large Info files are now split automatically, it is
no longer necessary to keep them small.@refill

Nowadays, multiple Texinfo files are used mostly for large documents,
such as @cite{The GNU Emacs Lisp Reference Manual}, and for projects
in which several different people write different sections of a
document simultaneously.@refill

In addition, the Info formatting commands have been extended to work
with the @code{@@include} command so as to create a single large Info
file that is split into smaller files if necessary.  This means that
you can write menus and cross references without naming the different
Texinfo files.@refill

@node Headings, Catching Mistakes, Include Files, Top
@comment  node-name,  next,  previous,  up
@appendix Page Headings
@cindex Headings
@cindex Footings
@cindex Page numbering
@cindex Page headings
@cindex Formatting headings and footings

Most printed manuals contain headings along the top of every page
except the title and copyright pages.  Some manuals also contain
footings.  (Headings and footings have no meaning to Info, which is
not paginated.)@refill

@menu
* Headings Introduced::         Conventions for using page headings.
* Heading Format::              Standard page heading formats.
* Heading Choice::              How to specify the type of page heading.
* Custom Headings::             How to create your own headings and footings.
@end menu

@node Headings Introduced, Heading Format, Headings, Headings
@ifinfo
@heading Headings Introduced
@end ifinfo

Texinfo provides standard page heading formats for manuals that are printed
on one side of each sheet of paper and for manuals that are printed on
both sides of the paper.  Usually, you will use one or other of these
formats, but you can specify your own format, if you wish.@refill

In addition, you can specify whether chapters should begin on a new
page, or merely continue the same page as the previous chapter; and if
chapters begin on new pages, you can specify whether they must be
odd-numbered pages.@refill

By convention, a book is printed on both sides of each sheet of paper.
When you open a book, the right-hand page is odd-numbered, and
chapters begin on right-hand pages---a preceding left-hand page is
left blank if necessary.  Reports, however, are often printed on just
one side of paper, and chapters begin on a fresh page immediately
following the end of the preceding chapter.  In short or informal
reports, chapters often do not begin on a new page at all, but are
separated from the preceding text by a small amount of whitespace.@refill

The @code{@@setchapternewpage} command controls whether chapters begin
on new pages, and whether one of the standard heading formats is used.
In addition, Texinfo has several heading and footing commands that you
can use to generate your own heading and footing formats.@refill

In Texinfo, headings and footings are single lines at the tops and
bottoms of pages; you cannot create multiline headings or footings.
Each header or footer line is divided into three parts: a left part, a
middle part, and a right part.  Any part, or a whole line, may be left
blank.  Text for the left part of a header or footer line is set
flushleft; text for the middle part is centered; and, text for the
right part is set flushright.@refill

@node Heading Format, Heading Choice, Headings Introduced, Headings
@comment  node-name,  next,  previous,  up
@appendixsec Standard Heading Formats

Texinfo provides two standard heading formats, one for manuals printed
on one side of each sheet of paper, and the other for manuals printed
on both sides of the paper.

By default, nothing is specified for the footing of a Texinfo file,
so the footing remains blank.@refill

The standard format for single-sided printing consists of a header
line in which the left-hand part contains the name of the chapter, the
central part is blank, and the right-hand part contains the page
number.@refill

@need 950
A single-sided page looks like this:

@example
@group
   _______________________
  |                       |
  | chapter   page number |
  |                       |
  | Start of text ...     |
  | ...                   |
  |                       |

@end group
@end example

The standard format for two-sided printing depends on whether the page
number is even or odd.  By convention, even-numbered pages are on the
left- and odd-numbered pages are on the right.  (@TeX{} will adjust the
widths of the left- and right-hand margins.  Usually, widths are
correct, but during double-sided printing, it is wise to check that
pages will bind properly---sometimes a printer will produce output in
which the even-numbered pages have a larger right-hand margin than the
odd-numbered pages.)@refill

In the standard double-sided format, the left part of the left-hand
(even-numbered) page contains the page number, the central part is
blank, and the right part contains the title (specified by the
@code{@@settitle} command).  The left part of the right-hand
(odd-numbered) page contains the name of the chapter, the central part
is blank, and the right part contains the page number.@refill

@need 750
Two pages, side by side as in an open book, look like this:@refill

@example
@group
   _______________________     _______________________
  |                       |   |                       |
  | page number     title |   | chapter   page number |
  |                       |   |                       |
  | Start of text ...     |   | More  text ...        |
  | ...                   |   | ...                   |
  |                       |   |                       |

@end group
@end example

@noindent
The chapter name is preceded by the word @samp{Chapter}, the chapter
number and a colon.  This makes it easier to keep track of where you
are in the manual.@refill

@node Heading Choice, Custom Headings, Heading Format, Headings
@comment  node-name,  next,  previous,  up
@appendixsec Specifying the Type of Heading

@TeX{} does not begin to generate page headings for a standard Texinfo
file until it reaches the @code{@@end titlepage} command.  Thus, the
title and copyright pages are not numbered.  The @code{@@end
titlepage} command causes @TeX{} to begin to generate page headings
according to a standard format specified by the
@code{@@setchapternewpage} command that precedes the
@code{@@titlepage} section.@refill

@need 1000
There are four possibilities:@refill

@table @asis
@item No @code{@@setchapternewpage} command
Cause @TeX{} to specify the single-sided heading format, with chapters
on new pages. This is the same as @code{@@setchapternewpage on}.@refill

@item @code{@@setchapternewpage on}
Specify the single-sided heading format, with chapters on new pages.@refill

@item @code{@@setchapternewpage off}
Cause @TeX{} to start a new chapter on the same page as the last page of
the preceding chapter, after skipping some vertical whitespace.  Also
cause @TeX{} to typeset for single-sided printing.  (You can override
the headers format with the @code{@@headings double} command; see
@ref{headings on off, , The @code{@@headings} Command}.)@refill

@item @code{@@setchapternewpage odd}
Specify the double-sided heading format, with chapters on new pages.@refill
@end table

@noindent
Texinfo lacks an @code{@@setchapternewpage even} command.@refill

@node Custom Headings, , Heading Choice, Headings
@comment  node-name,  next,  previous,  up
@appendixsec How to Make Your Own Headings

You can use the standard headings provided with Texinfo or specify
your own.@refill

@c Following paragraph is verbose to prevent overfull hboxes.
Texinfo provides six commands for specifying headings and
footings.  The @code{@@everyheading} command and
@code{@@everyfooting} command generate page headers and footers
that are the same for both even- and odd-numbered pages.
The @code{@@evenheading} command and @code{@@evenfooting}
command generate headers and footers for even-numbered
(left-hand) pages; and the @code{@@oddheading} command and
@code{@@oddfooting} command generate headers and footers for
odd-numbered (right-hand) pages.@refill

Write custom heading specifications in the Texinfo file immediately
after the @code{@@end titlepage} command.  Enclose your specifications
between @code{@@iftex} and @code{@@end iftex} commands since the
@code{texinfo-format-buffer} command may not recognize them.  Also,
you must cancel the predefined heading commands with the
@code{@@headings off} command before defining your own
specifications.@refill

@need 1000
Here is how to tell @TeX{} to place the chapter name at the left, the
page number in the center, and the date at the right of every header
for both even- and odd-numbered pages:@refill

@example
@group
@@iftex
@@headings off
@@everyheading @@thischapter @@| @@thispage @@| @@today@{@}
@@end iftex
@end group
@end example

@noindent
You need to divide the left part from the central part and the central
part from the right had part by inserting @samp{@@|} between parts.
Otherwise, the specification command will not be able to tell where
the text for one part ends and the next part begins.@refill

Each part can contain text or @@-commands.  The text
is printed as if the part were within an ordinary paragraph in the
body of the page.  The @@-commands replace
themselves with the page number, date, chapter name, or
whatever.@refill

@need 950
Here are the six heading and footing commands:@refill

@findex everyheading
@findex everyfooting
@table @code
@item @@everyheading @var{left} @@| @var{center} @@| @var{right}
@itemx @@everyfooting @var{left} @@| @var{center} @@| @var{right}

The `every' commands specify the format for both even- and odd-numbered
pages.  These commands are for documents that are printed on one side
of each sheet of paper, or for documents in which you want symmetrical
headers or footers.@refill

@findex evenheading
@findex evenfooting
@findex oddheading
@findex oddfooting
@item @@evenheading @var{left} @@| @var{center} @@| @var{right}
@itemx @@oddheading  @var{left} @@| @var{center} @@| @var{right}

@itemx @@evenfooting @var{left} @@| @var{center} @@| @var{right}
@itemx @@oddfooting  @var{left} @@| @var{center} @@| @var{right}

The `even' and `odd' commands specify the format for even-numbered
pages and odd-numbered pages.  These commands are for books and
manuals that are printed on both sides of each sheet of paper.@refill
@end table

Use the @samp{@@this@dots{}} series of @@-commands to
provide the names of chapters
and sections and the page number.  You can use the
@samp{@@this@dots{}} commands in the left, center, or right portions
of headers and footers, or anywhere else in a Texinfo file so long as
they are between @code{@@iftex} and @code{@@end iftex} commands.@refill

@need 1000
Here are the @samp{@@this@dots{}} commands:@refill

@table @code
@findex thispage
@item @@thispage
Expands to the current page number.@refill
@c !!! Karl Berry says that `thissection' fails on page breaks.
@ignore
@item @@thissection
Expands to the name of the current section.@refill
@end ignore

@findex thischaptername
@item @@thischaptername
Expands to the name of the current chapter.@refill

@findex thischapter
@item @@thischapter
Expands to the number and name of the current
chapter, in the format `Chapter 1: Title'.@refill

@findex thistitle
@item @@thistitle
Expands to the name of the document, as specified by the
@code{@@settitle} command.@refill

@findex thisfile
@item @@thisfile
For @code{@@include} files only: expands to the name of the current
@code{@@include} file.  If the current Texinfo source file is not an
@code{@@include} file, this command has no effect.  This command does
@emph{not} provide the name of the current Texinfo source file unless
it is an @code{@@include} file.  (@xref{Include Files}, for more
information about @code{@@include} files.)@refill
@end table

@noindent
You can also use the @code{@@today@{@}} command, which expands to the
current date, in `1 Jan 1900' format.@refill
@findex today

Other @@-commands and text are printed in a header or footer just as
if they were in the body of a page.  It is useful to incorporate text,
particularly when you are writing drafts:@refill

@example
@group
@@iftex
@@headings off
@@everyheading @@emph@{Draft!@} @@| @@thispage @@| @@thischapter
@@everyfooting @@| @@| Version: 0.27: @@today@{@}
@@end iftex
@end group
@end example

Beware of overlong titles: they may overlap another part of the
header or footer and blot it out.@refill

@node Catching Mistakes, Refilling Paragraphs, Headings, Top
@comment  node-name,  next,  previous,  up
@appendix Formatting Mistakes
@cindex Structure, catching mistakes in
@cindex Nodes, catching mistakes
@cindex Catching mistakes
@cindex Correcting mistakes
@cindex Mistakes, catching
@cindex Problems, catching
@cindex Debugging the Texinfo structure

Besides mistakes in the content of your documentation, there
are two kinds of mistake you can make with Texinfo:  you can make mistakes
with @@-commands, and you can make mistakes with the structure of the
nodes and chapters.@refill

Emacs has two tools for catching the @@-command mistakes and two for
catching structuring mistakes.@refill

For finding problems with @@-commands, you can run @TeX{} or a region
formatting command on the region that has a problem; indeed, you can
run these commands on each region as you write it.@refill

For finding problems with the structure of nodes and chapters, you can use
@kbd{C-c C-s} (@code{texinfo-show-structure}) and the related @code{occur}
command and you can use the @kbd{M-x Info-validate} command.@refill

@menu
* makeinfo preferred::          @code{makeinfo} finds errors.
* Debugging with Info::         How to catch errors with Info formatting.
* Debugging with TeX::          How to catch errors with @TeX{} formatting.
* Using texinfo-show-structure::  How to use @code{texinfo-show-structure}.
* Using occur::                 How to list all lines containing a pattern.
* Running Info-Validate::       How to find badly referenced nodes.
@end menu

@node makeinfo preferred, Debugging with Info, Catching Mistakes, Catching Mistakes
@ifinfo
@heading @code{makeinfo} Find Errors
@end ifinfo

The @code{makeinfo} program does an excellent job of catching errors
and reporting them---far better than @code{texinfo-format-region} or
@code{texinfo-format-buffer}.  In addition, the various functions for
automatically creating and updating node pointers and menus remove
many opportunities for human error.@refill

If you can, use the updating commands to create and insert pointers
and menus.  These prevent many errors.  Then use @code{makeinfo} (or
its Texinfo mode manifestations, @code{makeinfo-region} and
@code{makeinfo-buffer}) to format your file and check for other
errors.  This is the best way to work with Texinfo.  But if you
cannot use @code{makeinfo}, or your problem is very puzzling, then you
may want to use the tools described in this appendix.@refill

@node Debugging with Info, Debugging with TeX, makeinfo preferred, Catching Mistakes
@comment  node-name,  next,  previous,  up
@appendixsec Catching Errors with Info Formatting
@cindex Catching errors with Info formatting
@cindex Debugging with Info formatting

After you have written part of a Texinfo file, you can use the
@code{texinfo-format-region} or the @code{makeinfo-region} command to
see whether the region formats properly.@refill

Most likely, however, you are reading this section because for some
reason you cannot use the @code{makeinfo-region} command; therefore, the
rest of this section presumes that you are using
@code{texinfo-format-region}.@refill

If you have made a mistake with an @@-command,
@code{texinfo-format-region} will stop processing at or after the
error and display an error message.  To see where in the buffer the
error occurred, switch to the @samp{*Info Region*} buffer; the cursor
will be in a position that is after the location of the error.  Also,
the text will not be formatted after the place where the error
occurred (or more precisely, where it was detected).@refill

For example, if you accidentally end a menu with the command @code{@@end
menus} with an `s' on the end, instead of with @code{@@end menu}, you
will see an error message that says:@refill

@example
@@end menus is not handled by texinfo
@end example

@noindent
The cursor will stop at the point in the buffer where the error
occurs, or not long after it.  The buffer will look like this:@refill

@example
@group
---------- Buffer: *Info Region* ----------
* Menu:

* Using texinfo-show-structure::  How to use
                                  `texinfo-show-structure'
                                  to catch mistakes.
* Running Info-Validate::         How to check for
                                  unreferenced nodes.
@@end menus
@point{}
---------- Buffer: *Info Region* ----------
@end group
@end example

The @code{texinfo-format-region} command sometimes provides slightly
odd error messages.  For example, the following cross reference fails to format:@refill

@example
(@@xref@{Catching Mistakes, for more info.)
@end example

@noindent
In this case, @code{texinfo-format-region} detects the missing closing
brace but displays a message that says @samp{Unbalanced parentheses}
rather than @samp{Unbalanced braces}.  This is because the formatting
command looks for mismatches between braces as if they were
parentheses.@refill

Sometimes @code{texinfo-format-region} fails to detect mistakes.  For
example, in the following, the closing brace is swapped with the
closing parenthesis:@refill

@example
(@@xref@{Catching Mistakes), for more info.@}
@end example

@noindent
Formatting produces:
@example
(*Note for more info.: Catching Mistakes)
@end example

The only way for you to detect this error is to realize that the
reference should have looked like this:@refill

@example
(*Note Catching Mistakes::, for more info.)
@end example

Incidentally, if you are reading this node in Info and type @kbd{f
@key{RET}} (@code{Info-follow-reference}), you will generate an error
message that says:

@example
No such node: "Catching Mistakes) The only way @dots{}
@end example

@noindent
This is because Info perceives the example of the error as the first
cross reference in this node and if you type a @key{RET} immediately
after typing the Info @kbd{f} command, Info will attempt to go to the
referenced node.  If you type @kbd{f catch @key{TAB} @key{RET}}, Info
will complete the node name of the correctly written example and take
you to the `Catching Mistakes' node.  (If you try this, you can return
from the `Catching Mistakes' node by typing @kbd{l}
(@code{Info-last}).)

@c !!! section on using Elisp debugger ignored.
@ignore
Sometimes @code{texinfo-format-region} will stop long after the
original error; this is because it does not discover the problem until
then.  In this case, you will need to backtrack.@refill

@c menu
@c * Using the Emacs Lisp Debugger::  How to use the Emacs Lisp debugger.
@c end menu

@c node Using the Emacs Lisp Debugger
@c appendixsubsec Using the Emacs Lisp Debugger
@c index Using the Emacs Lisp debugger
@c index Emacs Lisp debugger
@c index Debugger, using the Emacs Lisp

If an error is especially elusive, you can turn on the Emacs Lisp
debugger and look at the backtrace; this tells you where in the
@code{texinfo-format-region} function the problem occurred.  You can
turn on the debugger with the command:@refill

@example
M-x set-variable @key{RET} debug-on-error @key{RET} t @key{RET}
@end example

@noindent
and turn it off with

@example
M-x set-variable @key{RET} debug-on-error @key{RET} nil @key{RET}
@end example

Often, when you are using the debugger, it is easier to follow what is
going on if you use the Emacs Lisp files that are not byte-compiled.
The byte-compiled sources send octal numbers to the debugger that may
look mysterious.  To use the uncompiled source files, load
@file{texinfmt.el} and @file{texinfo.el} with the @kbd{M-x load-file}
command.@refill

The debugger will not catch an error if @code{texinfo-format-region}
does not detect one.  In the example shown above,
@code{texinfo-format-region} did not find the error when the whole
list was formatted, but only when part of the list was formatted.
When @code{texinfo-format-region} did not find an error, the debugger
did not find one either. @refill

However, when @code{texinfo-format-region} did report an error, it
invoked the debugger.  This is the backtrace it produced:@refill

@example
---------- Buffer: *Backtrace* ----------
Signalling: (search-failed "[@},]")
  re-search-forward("[@},]")
  (while ...)
  (let ...)
  texinfo-format-parse-args()
  (let ...)
  texinfo-format-xref()
  funcall(texinfo-format-xref)
  (if ...)
  (let ...)
  (if ...)
  (while ...)
  texinfo-format-scan()
  (save-excursion ...)
  (let ...)
  texinfo-format-region(103370 103631)
* call-interactively(texinfo-format-region)
---------- Buffer: *Backtrace* ----------
@end example

The backtrace is read from the bottom up.
@code{texinfo-format-region} was called interactively; and it, in
turn, called various functions, including @code{texinfo-format-scan},
@code{texinfo-format-xref} and @code{texinfo-format-parse-args}.
Inside the function @code{texinfo-format-parse-args}, the function
@code{re-search-forward} was called; it was this function that could
not find the missing right-hand brace.@refill

@xref{Lisp Debug, , Debugging Emacs Lisp, emacs, The GNU Emacs
Manual}, for more information.@refill
@end ignore

@node Debugging with TeX, Using texinfo-show-structure, Debugging with Info, Catching Mistakes
@comment  node-name,  next,  previous,  up
@appendixsec Catching Errors with @TeX{} Formatting
@cindex Catching errors with @TeX{} formatting
@cindex Debugging with @TeX{} formatting

You can also catch mistakes when you format a file with @TeX{}.@refill

Usually, you will want to do this after you have run
@code{texinfo-format-buffer} (or, better, @code{makeinfo-buffer}) on
the same file, because @code{texinfo-format-buffer} sometimes displays
error messages that make more sense than @TeX{}.  (@xref{Debugging
with Info}, for more information.)@refill

For example, @TeX{} was run on a Texinfo file, part of which is shown
here:@refill

@example
---------- Buffer: texinfo.texi ----------
name of the Texinfo file as an extension.  The
@@samp@{??@} are `wildcards' that cause the shell to
substitute all the raw index files.  (@@xref@{sorting
indices, for more information about sorting
indices.)@@refill
---------- Buffer: texinfo.texi ----------
@end example

@noindent
(The cross reference lacks a closing brace.)
@TeX{} produced the following output, after which it stopped:@refill

@example
---------- Buffer: *tex-shell* ----------
Runaway argument?
@{sorting indices, for more information about sorting
indices.) @@refill @@ETC.
! Paragraph ended before @@xref was complete.
<to be read again>
                   @@par
l.27

?
---------- Buffer: *tex-shell* ----------
@end example

In this case, @TeX{} produced an accurate and
understandable error message:

@example
Paragraph ended before @@xref was complete.
@end example

@noindent
@samp{@@par} is an internal @TeX{} command of no relevance to Texinfo.
@samp{l.27} means that @TeX{} detected the problem on line 27 of the
Texinfo file.  The @samp{?} is the prompt @TeX{} uses in this
circumstance.@refill

Unfortunately, @TeX{} is not always so helpful, and sometimes you must
truly be a Sherlock Holmes to discover what went wrong.@refill

In any case, if you run into a problem like this, you can do one of three
things.@refill

@enumerate
@item
You can tell @TeX{} to continue running and ignore just this error by
typing @key{RET} at the @samp{?} prompt.@refill

@item
You can tell @TeX{} to continue running and to ignore all errors as best
it can by typing @kbd{r @key{RET}} at the @samp{?} prompt.@refill

This is often the best thing to do.  However, beware: the one error
may produce a cascade of additional error messages as its consequences
are felt through the rest of the file.  (To stop @TeX{} when it is
producing such an avalanche of error messages, type @kbd{C-d} (or
@kbd{C-c C-d}, if you are running a shell inside Emacs.))@refill

@item
You can tell @TeX{} to stop this run by typing @kbd{x @key{RET}}
at the @samp{?} prompt.@refill
@end enumerate

Please note that if you are running @TeX{} inside Emacs, you need to
switch to the shell buffer and line at which @TeX{} offers the @samp{?}
prompt.@refill

Sometimes @TeX{} will format a file without producing error messages even
though there is a problem.  This usually occurs if a command is not ended
but @TeX{} is able to continue processing anyhow.  For example, if you fail
to end an itemized list with the @code{@@end itemize} command, @TeX{} will
write a @sc{dvi} file that you can print out.  The only error message that
@TeX{} will give you is the somewhat mysterious comment that@refill

@example
(@@end occurred inside a group at level 1)
@end example

@noindent
However, if you print the @sc{dvi} file, you will find that the text
of the file that follows the itemized list is entirely indented as if
it were part of the last item in the itemized list.  The error message
is the way @TeX{} says that it expected to find an @code{@@end}
command somewhere in the file; but that it could not determine where
it was needed.@refill

Another source of notoriously hard-to-find errors is a missing
@code{@@end group} command.  If you ever are stumped by
incomprehensible errors, look for a missing @code{@@end group} command
first.@refill

If the Texinfo file lacks header lines,
@TeX{} may stop in the
beginning of its run and display output that looks like the following.
The @samp{*} indicates that @TeX{} is waiting for input.@refill

@example
This is TeX, Version 3.14159 (Web2c 7.0)
(test.texinfo [1])
*
@end example

@noindent
In this case, simply type @kbd{\end @key{RET}} after the asterisk.  Then
write the header lines in the Texinfo file and run the @TeX{} command
again. (Note the use of the backslash, @samp{\}.  @TeX{} uses @samp{\}
instead of @samp{@@}; and in this circumstance, you are working
directly with @TeX{}, not with Texinfo.)@refill

@node Using texinfo-show-structure, Using occur, Debugging with TeX, Catching Mistakes
@comment  node-name,  next,  previous,  up
@appendixsec Using @code{texinfo-show-structure}
@cindex Showing the structure of a file
@findex texinfo-show-structure

It is not always easy to keep track of the nodes, chapters, sections, and
subsections of a Texinfo file.  This is especially true if you are revising
or adding to a Texinfo file that someone else has written.@refill

In GNU Emacs, in Texinfo mode, the @code{texinfo-show-structure}
command lists all the lines that begin with the @@-commands that
specify the structure: @code{@@chapter}, @code{@@section},
@code{@@appendix}, and so on.  With an argument (@w{@kbd{C-u}}
as prefix argument, if interactive),
the command also shows the @code{@@node} lines.  The
@code{texinfo-show-structure} command is bound to @kbd{C-c C-s} in
Texinfo mode, by default.@refill

The lines are displayed in a buffer called the @samp{*Occur*} buffer,
indented by hierarchical level.  For example, here is a part of what was
produced by running @code{texinfo-show-structure} on this manual:@refill

@example
@group
 Lines matching "^@@\\(chapter \\|sect\\|subs\\|subh\\|
 unnum\\|major\\|chapheading \\|heading \\|appendix\\)"
 in buffer texinfo.texi.
 @dots{}
 4177:@@chapter Nodes
 4198:    @@heading Two Paths
 4231:    @@section Node and Menu Illustration
 4337:    @@section The @@code@{@@@@node@} Command
 4393:        @@subheading Choosing Node and Pointer Names
 4417:        @@subsection How to Write an @@code@{@@@@node@} Line
 4469:        @@subsection @@code@{@@@@node@} Line Tips
 @dots{}
@end group
@end example

This says that lines 4337, 4393, and 4417 of @file{texinfo.texi} begin
with the @code{@@section}, @code{@@subheading}, and @code{@@subsection}
commands respectively.  If you move your cursor into the @samp{*Occur*}
window, you can position the cursor over one of the lines and use the
@kbd{C-c C-c} command (@code{occur-mode-goto-occurrence}), to jump to
the corresponding spot in the Texinfo file.  @xref{Other Repeating
Search, , Using Occur, emacs, The GNU Emacs Manual}, for more
information about @code{occur-mode-goto-occurrence}.@refill

The first line in the @samp{*Occur*} window describes the @dfn{regular
expression} specified by @var{texinfo-heading-pattern}.  This regular
expression is the pattern that @code{texinfo-show-structure} looks for.
@xref{Regexps, , Using Regular Expressions, emacs, The GNU Emacs Manual},
for more information.@refill

When you invoke the @code{texinfo-show-structure} command, Emacs will
display the structure of the whole buffer.  If you want to see the
structure of just a part of the buffer, of one chapter, for example,
use the @kbd{C-x n n} (@code{narrow-to-region}) command to mark the
region.  (@xref{Narrowing, , , emacs, The GNU Emacs Manual}.)  This is
how the example used above was generated.  (To see the whole buffer
again, use @kbd{C-x n w} (@code{widen}).)@refill

If you call @code{texinfo-show-structure} with a prefix argument by
typing @w{@kbd{C-u C-c C-s}}, it will list lines beginning with
@code{@@node} as well as the lines beginning with the @@-sign commands
for @code{@@chapter}, @code{@@section}, and the like.@refill

You can remind yourself of the structure of a Texinfo file by looking at
the list in the @samp{*Occur*} window; and if you have mis-named a node
or left out a section, you can correct the mistake.@refill

@node Using occur, Running Info-Validate, Using texinfo-show-structure, Catching Mistakes
@comment  node-name,  next,  previous,  up
@appendixsec Using @code{occur}
@cindex Occurrences, listing with @code{@@occur}
@findex occur

Sometimes the @code{texinfo-show-structure} command produces too much
information.  Perhaps you want to remind yourself of the overall structure
of a Texinfo file, and are overwhelmed by the detailed list produced by
@code{texinfo-show-structure}.  In this case, you can use the @code{occur}
command directly.  To do this, type@refill

@example
@kbd{M-x occur}
@end example

@noindent
and then, when prompted, type a @dfn{regexp}, a regular expression for
the pattern you want to match.  (@xref{Regexps, , Regular Expressions,
emacs, The GNU Emacs Manual}.)  The @code{occur} command works from
the current location of the cursor in the buffer to the end of the
buffer.  If you want to run @code{occur} on the whole buffer, place
the cursor at the beginning of the buffer.@refill

For example, to see all the lines that contain the word
@samp{@@chapter} in them, just type @samp{@@chapter}.  This will
produce a list of the chapters.  It will also list all the sentences
with @samp{@@chapter} in the middle of the line.@refill

If you want to see only those lines that start with the word
@samp{@@chapter}, type @samp{^@@chapter} when prompted by
@code{occur}.  If you want to see all the lines that end with a word
or phrase, end the last word with a @samp{$}; for example,
@samp{catching mistakes$}.  This can be helpful when you want to see
all the nodes that are part of the same chapter or section and
therefore have the same `Up' pointer.@refill

@xref{Other Repeating Search, , Using Occur, emacs , The GNU Emacs Manual},
for more information.@refill

@node Running Info-Validate, , Using occur, Catching Mistakes
@comment  node-name,  next,  previous,  up
@appendixsec Finding Badly Referenced Nodes
@findex Info-validate
@cindex Nodes, checking for badly referenced
@cindex Checking for badly referenced nodes
@cindex Looking for badly referenced nodes
@cindex Finding badly referenced nodes
@cindex Badly referenced nodes

You can use the @code{Info-validate} command to check whether any of
the `Next', `Previous', `Up' or other node pointers fail to point to a
node.  This command checks that every node pointer points to an
existing node.  The @code{Info-validate} command works only on Info
files, not on Texinfo files.@refill

The @code{makeinfo} program validates pointers automatically, so you
do not need to use the @code{Info-validate} command if you are using
@code{makeinfo}.  You only may need to use @code{Info-validate} if you
are unable to run @code{makeinfo} and instead must create an Info file
using @code{texinfo-format-region} or @code{texinfo-format-buffer}, or
if you write an Info file from scratch.@refill

@menu
* Using Info-validate::         How to run @code{Info-validate}.
* Unsplit::                     How to create an unsplit file.
* Tagifying::                   How to tagify a file.
* Splitting::                   How to split a file manually.
@end menu

@node Using Info-validate, Unsplit, Running Info-Validate, Running Info-Validate
@appendixsubsec Running @code{Info-validate}
@cindex Running @code{Info-validate}
@cindex Info validating a large file
@cindex Validating a large file

To use @code{Info-validate}, visit the Info file you wish to check and
type:@refill

@example
M-x Info-validate
@end example

@noindent
(Note that the @code{Info-validate} command requires an upper case
`I'.  You may also need to create a tag table before running
@code{Info-validate}.  @xref{Tagifying}.)@refill

If your file is valid, you will receive a message that says ``File appears
valid''.  However, if you have a pointer that does not point to a node,
error messages will be displayed in a buffer called @samp{*problems in
info file*}.@refill

For example, @code{Info-validate} was run on a test file that contained
only the first node of this manual.  One of the messages said:@refill

@example
In node "Overview", invalid Next: Texinfo Mode
@end example

@noindent
This meant that the node called @samp{Overview} had a `Next' pointer that
did not point to anything (which was true in this case, since the test file
had only one node in it).@refill

Now suppose we add a node named @samp{Texinfo Mode} to our test case
but we do not specify a `Previous' for this node.  Then we will get
the following error message:@refill

@example
In node "Texinfo Mode", should have Previous: Overview
@end example

@noindent
This is because every `Next' pointer should be matched by a
`Previous' (in the node where the `Next' points) which points back.@refill

@code{Info-validate} also checks that all menu entries and cross references
point to actual nodes.@refill

Note that @code{Info-validate} requires a tag table and does not work
with files that have been split.  (The @code{texinfo-format-buffer}
command automatically splits large files.)  In order to use
@code{Info-validate} on a large file, you must run
@code{texinfo-format-buffer} with an argument so that it does not split
the Info file; and you must create a tag table for the unsplit
file.@refill

@node Unsplit, Tagifying, Using Info-validate, Running Info-Validate
@comment  node-name,  next,  previous,  up
@appendixsubsec Creating an Unsplit File
@cindex Creating an unsplit file
@cindex Unsplit file creation

You can run @code{Info-validate} only on a single Info file that has a
tag table.  The command will not work on the indirect subfiles that
are generated when a master file is split.  If you have a large file
(longer than 70,000 bytes or so), you need to run the
@code{texinfo-format-buffer} or @code{makeinfo-buffer} command in such
a way that it does not create indirect subfiles.  You will also need
to create a tag table for the Info file.  After you have done this,
you can run @code{Info-validate} and look for badly referenced
nodes.@refill

The first step is to create an unsplit Info file.  To prevent
@code{texinfo-format-buffer} from splitting a Texinfo file into
smaller Info files, give a prefix to the @kbd{M-x
texinfo-format-buffer} command:@refill

@example
C-u M-x texinfo-format-buffer
@end example

@noindent
or else

@example
C-u C-c C-e C-b
@end example

@noindent
When you do this, Texinfo will not split the file and will not create
a tag table for it. @refill
@cindex Making a tag table manually
@cindex Tag table, making manually

@node Tagifying, Splitting, Unsplit, Running Info-Validate
@appendixsubsec Tagifying a File

After creating an unsplit Info file, you must create a tag table for
it.  Visit the Info file you wish to tagify and type:@refill

@example
M-x Info-tagify
@end example

@noindent
(Note the upper case @samp{I} in @code{Info-tagify}.)  This creates an
Info file with a tag table that you can validate.@refill

The third step is to validate the Info file:@refill

@example
M-x Info-validate
@end example

@noindent
(Note the upper case @samp{I} in @code{Info-validate}.)
In brief, the steps are:@refill

@example
@group
C-u M-x texinfo-format-buffer
M-x Info-tagify
M-x Info-validate
@end group
@end example

After you have validated the node structure, you can rerun
@code{texinfo-format-buffer} in the normal way so it will construct a
tag table and split the file automatically, or you can make the tag
table and split the file manually.@refill

@node Splitting, , Tagifying, Running Info-Validate
@comment  node-name,  next,  previous,  up
@appendixsubsec Splitting a File Manually
@cindex Splitting an Info file manually
@cindex Info file, splitting manually

You should split a large file or else let the
@code{texinfo-format-buffer} or @code{makeinfo-buffer} command do it
for you automatically.  (Generally you will let one of the formatting
commands do this job for you.  @xref{Create an Info File}.)@refill

The split-off files are called the indirect subfiles.@refill

Info files are split to save memory.  With smaller files, Emacs does not
have make such a large buffer to hold the information.@refill

If an Info file has more than 30 nodes, you should also make a tag
table for it. @xref{Using Info-validate}, for information
about creating a tag table.  (Again, tag tables are usually created
automatically by the formatting command; you only need to create a tag
table yourself if you are doing the job manually.  Most likely, you
will do this for a large, unsplit file on which you have run
@code{Info-validate}.)@refill

@c Info-split is autoloaded in `loaddefs.el' in Emacs 18.51
@ignore
Before running @code{Info-split}, you need to load the @code{info} library
into Emacs by giving the command @kbd{M-x load-library @key{RET} info
@key{RET}}.
@end ignore

Visit the Info file you wish to tagify and split and type the two
commands:@refill

@example
M-x Info-tagify
M-x Info-split
@end example

@noindent
(Note that the @samp{I} in @samp{Info} is upper case.)@refill

When you use the @code{Info-split} command, the buffer is modified into a
(small) Info file which lists the indirect subfiles.  This file should be
saved in place of the original visited file.  The indirect subfiles are
written in the same directory the original file is in, with names generated
by appending @samp{-} and a number to the original file name.@refill

The primary file still functions as an Info file, but it contains just
the tag table and a directory of subfiles.@refill

@node Refilling Paragraphs, Command Syntax, Catching Mistakes, Top
@comment  node-name,  next,  previous,  up
@appendix Refilling Paragraphs
@cindex Refilling paragraphs
@cindex Filling paragraphs
@findex refill

The @code{@@refill} command refills and, optionally, indents the first
line of a paragraph.@footnote{Perhaps the command should have been
called the @code{@@refillandindent} command, but @code{@@refill} is
shorter and the name was chosen before indenting was possible.} The
@code{@@refill} command is no longer important, but we describe it here
because you once needed it.  You will see it in many old Texinfo
files.@refill

Without refilling, paragraphs containing long @@-constructs may look
bad after formatting because the formatter removes @@-commands and
shortens some lines more than others.  In the past, neither the
@code{texinfo-format-region} command nor the
@code{texinfo-format-buffer} command refilled paragraphs
automatically.  The @code{@@refill} command had to be written at the
end of every paragraph to cause these formatters to fill them.  (Both
@TeX{} and @code{makeinfo} have always refilled paragraphs
automatically.)  Now, all the Info formatters automatically fill and
indent those paragraphs that need to be filled and indented.@refill

The @code{@@refill} command causes @code{texinfo-format-region} and
@code{texinfo-format-buffer} to refill a paragraph in the Info file
@emph{after} all the other processing has been done.  For this reason,
you can not use @code{@@refill} with a paragraph containing either
@code{@@*} or @code{@@w@{ @dots{} @}} since the refilling action will
override those two commands.@refill

The @code{texinfo-format-region} and @code{texinfo-format-buffer}
commands now automatically append @code{@@refill} to the end of each
paragraph that should be filled.  They do not append @code{@@refill} to
the ends of paragraphs that contain @code{@@*} or @w{@code{@@w@{ @dots{}@}}}
and therefore do not refill or indent them.@refill

@node Command Syntax, Obtaining TeX, Refilling Paragraphs, Top
@comment node-name,  next,  previous,  up
@appendix @@-Command Syntax
@cindex @@-command syntax

The character @samp{@@} is used to start special Texinfo commands.
(It has the same meaning that @samp{\} has in plain @TeX{}.)  Texinfo
has four types of @@-command:@refill

@table @asis
@item 1. Non-alphabetic commands.
These commands consist of an @@ followed by a punctuation mark or other
character that is not part of the alphabet.  Non-alphabetic commands
are almost always part of the text within a paragraph, and never take
any argument.  The two characters (@@ and the other one) are complete
in themselves; none is followed by braces.  The non-alphabetic
commands are: @code{@@.}, @code{@@:}, @code{@@*}, @code{@@@@},
@code{@@@{}, and @code{@@@}}.@refill

@item 2. Alphabetic commands that do not require arguments.
These commands start with @@ followed by a word followed by left- and
right-hand braces.  These commands insert special symbols in the
document; they do not require arguments.  For example,
@code{@@dots@{@}} @result{} @samp{@dots{}}, @code{@@equiv@{@}}
@result{} @samp{@equiv{}}, @code{@@TeX@{@}} @result{} `@TeX{}',
and @code{@@bullet@{@}} @result{} @samp{@bullet{}}.@refill

@item 3. Alphabetic commands that require arguments within braces.
These commands start with @@ followed by a letter or a word, followed by an
argument within braces.  For example, the command @code{@@dfn} indicates
the introductory or defining use of a term; it is used as follows: @samp{In
Texinfo, @@@@-commands are @@dfn@{mark-up@} commands.}@refill

@item 4. Alphabetic commands that occupy an entire line.
These commands occupy an entire line.  The line starts with @@,
followed by the name of the command (a word); for example, @code{@@center}
or @code{@@cindex}.  If no argument is needed, the word is followed by
the end of the line.  If there is an argument, it is separated from
the command name by a space.  Braces are not used.@refill
@end table

@cindex Braces and argument syntax
Thus, the alphabetic commands fall into classes that have
different argument syntaxes.  You cannot tell to which class a command
belongs by the appearance of its name, but you can tell by the
command's meaning: if the command stands for a glyph, it is in
class 2 and does not require an argument; if it makes sense to use the
command together with other text as part of a paragraph, the command
is in class 3 and must be followed by an argument in braces;
otherwise, it is in class 4 and uses the rest of the line as its
argument.@refill

The purpose of having a different syntax for commands of classes 3 and
4 is to make Texinfo files easier to read, and also to help the GNU
Emacs paragraph and filling commands work properly.  There is only one
exception to this rule: the command @code{@@refill}, which is always
used at the end of a paragraph immediately following the final period
or other punctuation character.  @code{@@refill} takes no argument and
does @emph{not} require braces.  @code{@@refill} never confuses the
Emacs paragraph commands because it cannot appear at the beginning of
a line.@refill

@node Obtaining TeX, New Features, Command Syntax, Top
@appendix How to Obtain @TeX{}
@cindex Obtaining @TeX{}
@cindex @TeX{}, how to obtain

@c !!! Here is information about obtaining TeX.  Update it whenever.
@c !!! Also consider updating TeX.README on prep.
@c     Updated by RJC on 1 March 1995, conversation with MacKay.
@c     Updated by kb@cs.umb.edu on 29 July 1996.
@TeX{} is freely redistributable.  You can obtain @TeX{} for Unix
systems via anonymous ftp or on tape or CD-ROM.  The core material
consists of Karl Berry's Web2c @TeX{} distribution.

On-line retrieval instructions are available from either:
@example
@url{ftp://ftp.tug.org/tex/unixtex.ftp}
@url{http://www.tug.org/unixtex.ftp}
@end example

The Free Software Foundation provides a core distribution on its Source
Code CD-ROM suitable for printing Texinfo manuals; the University of
Washington maintains and supports a tape distribution; the @TeX{} Users
Group co-sponsors a complete CD-ROM @TeX{} distribution.

For the FSF Source Code CD-ROM, please contact:

@iftex
@display
@group
Free Software Foundation, Inc.
59 Temple Place Suite 330
Boston, MA w{ } 02111-1307
USA

Telephone: @w{@t{+}1--617--542--5942}
Fax: (including Japan) @w{@t{+}1--617--542--2652}
Free Dial Fax (in Japan):
@w{ } @w{ } @w{ } 0031--13--2473 (KDD)
@w{ } @w{ } @w{ } 0066--3382--0158 (IDC)
Electronic mail: @code{gnu@@prep.ai.mit.edu}
@end group
@end display
@end iftex
@ifinfo
@display
@group
Free Software Foundation, Inc.
59 Temple Place Suite 330
Boston, MA @w{ } 02111-1307
USA

Telephone: @w{@t{+}1-617-542-5942}
Fax: (including Japan) @w{@t{+}1-617-542-2652}
Free Dial Fax (in Japan):
@w{ } @w{ } @w{ } 0031-13-2473 (KDD)
@w{ } @w{ } @w{ } 0066-3382-0158 (IDC)
Electronic mail: @code{gnu@@prep.ai.mit.edu}
@end group
@end display
@end ifinfo

To order a full distribution on CD-ROM, please see:
@display
@url{http://www.tug.org/tex-live.html}
@end display

@noindent
(The distribution is also available by FTP; see the URL's above.)

To order a full distribution from the University of Washington on either a
1/4@dmn{in} 4-track QIC-24 cartridge or a 4@dmn{mm} DAT cartridge, send
$210 to:

@display
@group
Pierre A. MacKay
Denny Hall, Mail Stop DH-10
University of Washington
Seattle, WA @w{ } 98195
USA

Telephone: @t{+}1--206--543--2268
Electronic mail: @code{mackay@@cs.washington.edu}
@end group
@end display

Please make checks payable to the University of Washington.
Checks must be in U.S.@: dollars, drawn on a U.S.@: bank.

Prepaid orders are the only orders that can now be handled.  Overseas
sites: please add to the base cost, if desired, $20.00 for shipment
via air parcel post, or $30.00 for shipment via courier.

Please check with the above for current prices and formats.


@node New Features, Command and Variable Index, Obtaining TeX, Top
@appendix Second Edition Features

@tex
% Widen the space for the first column so three control-character
% strings fit in the first column.  Switched back to default .8in
% value at end of chapter.
\global\tableindent=1.0in
@end tex

The second edition of the Texinfo manual describes more than 20 new
Texinfo mode commands and more than 50 previously undocumented Texinfo
@@-commands.  This edition is more than twice the length of the first
edition.@refill

Here is a brief description of the new commands.@refill

@menu
* New Texinfo Mode Commands::   The updating commands are especially useful.
* New Commands::                Many newly described @@-commands.
@end menu

@node New Texinfo Mode Commands, New Commands, New Features, New Features
@appendixsec New Texinfo Mode Commands

Texinfo mode provides commands and features especially designed for
working with Texinfo files.  More than 20 new commands have been
added, including commands for automatically creating and updating
both nodes and menus.  This is a tedious task when done by hand.@refill

The keybindings are intended to be somewhat mnemonic.@refill

@subheading Update all nodes and menus

The @code{texinfo-master-menu} command is the primary command:

@table @kbd
@item C-c C-u m
@itemx M-x texinfo-master-menu
Create or update a master menu.
With @kbd{C-u} as a prefix argument,
first create or update all nodes
and regular menus.
@end table

@subheading Update Pointers

@noindent
Create or update `Next', `Previous', and `Up' node pointers.@refill

@noindent
@xref{Updating Nodes and Menus}.

@table @kbd
@item C-c C-u C-n
@itemx M-x texinfo-update-node
Update a node.

@item C-c C-u C-e
@itemx M-x texinfo-every-node-update
Update every node in the buffer.
@end table

@subheading Update Menus

@noindent
Create or update menus.@refill

@noindent
@xref{Updating Nodes and Menus}.

@table @kbd
@item C-c C-u C-m
@itemx M-x texinfo-make-menu
Make or update a menu.

@item C-c C-u C-a
@itemx M-x texinfo-all-menus-update
Make or update all the menus in a buffer.
With @kbd{C-u} as a prefix argument,
first update all the nodes.
@end table

@subheading Insert Title as Description

@noindent
Insert a node's chapter or section title in the space for the
description in a menu entry line; position point so you can edit the
insert.  (This command works somewhat differently than the other
insertion commands, which insert only a predefined string.)@refill

@noindent
@xref{Inserting, Inserting Frequently Used Commands}.

@table @kbd
@item C-c C-c C-d
Insert title.
@end table

@subheading Format for Info

@noindent
Provide keybindings both for the Info formatting commands that are
written in Emacs Lisp and for @code{makeinfo} that is written in
C.@refill

@noindent
@xref{Info Formatting}.

@noindent
Use the Emacs lisp @code{texinfo-format@dots{}} commands:

@table @kbd
@item C-c C-e C-r
Format the region.

@item C-c C-e C-b
Format the buffer.
@end table

@noindent
Use @code{makeinfo}:

@table @kbd
@item C-c C-m C-r
Format the region.

@item C-c C-m C-b
Format the buffer.

@item C-c C-m C-l
Recenter the @code{makeinfo} output buffer.

@item C-c C-m C-k
Kill the @code{makeinfo} formatting job.
@end table

@subheading Typeset and Print

@noindent
Typeset and print Texinfo documents from within Emacs.@refill

@ifinfo
@noindent
@xref{Printing}.
@end ifinfo
@iftex
@noindent
@xref{Printing, , Formatting and Printing}.
@end iftex

@table @kbd
@item C-c C-t C-b
Run @code{texi2dvi} on the buffer.

@item C-c C-t C-r
Run @TeX{} on the region.

@item C-c C-t C-i
Run @code{texindex}.

@item C-c C-t C-p
Print the @sc{dvi} file.

@item C-c C-t C-q
Show the print queue.

@item C-c C-t C-d
Delete a job from the print queue.

@item C-c C-t C-k
Kill the current @TeX{} formatting job.

@item C-c C-t C-x
Quit a currently stopped @TeX{} formatting job.

@item C-c C-t C-l
Recenter the output buffer.
@end table

@subheading Other Updating Commands

@noindent
The ``other updating commands'' do not have standard keybindings because
they are used less frequently.@refill

@noindent
@xref{Other Updating Commands}.

@table @kbd
@item M-x texinfo-insert-node-lines
Insert missing @code{@@node} lines using
section titles as node names.

@item M-x texinfo-multiple-files-update
Update a multi-file document.
With a numeric prefix, such as @kbd{C-u 8},
update  @strong{every} pointer and
menu in @strong{all} the files and
then insert a master menu.

@item M-x texinfo-indent-menu-description
Indent descriptions in menus.

@item M-x texinfo-sequential-node-update
Insert node pointers in strict sequence.
@end table

@node New Commands, , New Texinfo Mode Commands, New Features
@appendixsec New Texinfo @@-Commands

The second edition of the Texinfo manual describes more than 50
commands that were not described in the first edition.  A third or so
of these commands existed in Texinfo but were not documented in the
manual; the others are new.  Here is a listing, with brief
descriptions of them:@refill

@subheading Indexing

@noindent
Create your own index, and merge indices.@refill

@noindent
@xref{Indices}.

@table @kbd
@item @@defindex @var{index-name}
Define a new index and its indexing command.
See also the @code{@@defcodeindex} command.

@c written verbosely to avoid overfull hbox
@item @@synindex @var{from-index} @var{into-index}
Merge the @var{from-index} index into the @var{into-index} index.
See also the @code{@@syncodeindex} command.
@end table

@subheading Definitions

@noindent
Describe functions, variables, macros,
commands, user options, special forms, and other such artifacts in a
uniform format.@refill

@noindent
@xref{Definition Commands}.

@table @kbd
@item @@deffn @var{category} @var{name} @var{arguments}@dots{}
Format a description for functions, interactive
commands, and similar entities.

@item @@defvr, @@defop, @dots{}
15 other related commands.
@end table

@subheading Glyphs

@noindent
Indicate the results of evaluation, expansion,
printed output, an error message, equivalence of expressions, and the
location of point.@refill

@noindent
@xref{Glyphs}.

@table @kbd
@item @@equiv@{@}
@itemx @equiv{}
Equivalence:

@item @@error@{@}
@itemx @error{}
Error message

@item @@expansion@{@}
@itemx @expansion{}
Macro expansion

@item @@point@{@}
@itemx @point{}
Position of point

@item @@print@{@}
@itemx @print{}
Printed output

@item @@result@{@}
@itemx @result{}
Result of an expression
@end table

@subheading Page Headings

@noindent
Customize page headings.

@noindent
@xref{Headings}.

@table @kbd
@item @@headings @var{on-off-single-double}
Headings on or off, single, or double-sided.

@item @@evenfooting [@var{left}] @@| [@var{center}] @@| [@var{right}]
Footings for even-numbered (left-hand) pages.

@item @@evenheading, @@everyheading, @@oddheading, @dots{}
Five other related commands.

@item @@thischapter
Insert name of chapter and chapter number.

@item @@thischaptername, @@thisfile, @@thistitle, @@thispage
Related commands.
@end table

@subheading Formatting

@noindent
Format blocks of text.

@noindent
@xref{Quotations and Examples}, and@*
@ref{Lists and Tables, , Making Lists and Tables}.

@table @kbd
@item @@cartouche
Draw rounded box surrounding text (not in Info).

@item @@enumerate @var{optional-arg}
Enumerate a list with letters or numbers.

@item @@exdent @var{line-of-text}
Remove indentation.

@item @@flushleft
Left justify.

@item @@flushright
Right justify.

@item @@format
Do not narrow nor change font.

@item @@ftable @var{formatting-command}
@itemx @@vtable @var{formatting-command}
Two-column table with indexing.

@item @@lisp
For an example of Lisp code.

@item @@smallexample
@itemx @@smalllisp
Like @@table and @@lisp @r{but for} @@smallbook.
@end table

@subheading Conditionals

@noindent
Conditionally format text.

@noindent
@xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill

@table @kbd
@item @@set @var{flag} [@var{string}]
Set a flag.  Optionally, set value
of @var{flag} to @var{string}.

@item @@clear @var{flag}
Clear a flag.

@item @@value@{@var{flag}@}
Replace with value to which @var{flag} is set.

@item @@ifset @var{flag}
Format, if @var{flag} is set.

@item @@ifclear @var{flag}
Ignore, if @var{flag} is set.
@end table

@subheading @@heading series for Titles

@noindent
Produce unnumbered headings that do not appear in a table of contents.

@noindent
@xref{Structuring}.

@table @kbd
@item @@heading @var{title}
Unnumbered section-like heading not listed
in the table of contents of a printed manual.

@item @@chapheading, @@majorheading, @@subheading, @@subsubheading
Related commands.
@end table

@need 1000
@subheading Font commands

@need 1000
@noindent
@xref{Smallcaps}, and @*
@ref{Fonts}.

@table @kbd
@item @@r@{@var{text}@}
Print in roman font.

@item @@sc@{@var{text}@}
Print in @sc{small caps} font.
@end table

@subheading Miscellaneous

@noindent
See @ref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author} Commands},@*
see @ref{Customized Highlighting},@*
see @ref{Overfull hboxes},@*
see @ref{Footnotes},@*
see @ref{dmn, , Format a Dimension},@*
see @ref{Raise/lower sections, , @code{@@raisesections} and @code{@@lowersections}},@*
see @ref{math, , @code{@@math}: Inserting Mathematical Expressions}.@*
see @ref{minus, , Inserting a Minus Sign},@*
see @ref{paragraphindent, , Paragraph Indenting},@*
see @ref{Cross Reference Commands},@*
see @ref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author}}, and@*
see @ref{Custom Headings, , How to Make Your Own Headings}.

@table @kbd
@item @@author @var{author}
Typeset author's name.

@ignore
@item @@definfoenclose @var{new-command}, @var{before}, @var{after},
Define a highlighting command for Info.  (Info only.)
@end ignore

@item @@finalout
Produce cleaner printed output.

@item @@footnotestyle @var{end-or-separate}
Specify footnote style.

@item @@dmn@{@var{dimension}@}
Format a dimension.

@item @@global@@let@var{new-cmd}=@var{existing-cmd}
Define a highlighting command for @TeX{}. (@TeX{} only.)

@item @@lowersections
Reduce hierarchical level of sectioning commands.

@item @@math@{@var{mathematical-expression}@}
Format a mathematical expression.

@item @@minus@{@}
Generate a minus sign.

@item @@paragraphindent @var{asis-or-number}
Specify paragraph indentation.

@item @@raisesections
Raise hierarchical level of sectioning commands.

@item @@ref@{@var{node-name}, @r{[}@var{entry}@r{]}, @r{[}@var{topic-or-title}@r{]}, @r{[}@var{info-file}@r{]}, @r{[}@var{manual}@r{]}@}
Make a reference.  In the printed manual, the
reference does not start with the word `see'.

@item @@title @var{title}
Typeset @var{title} in the alternative
title page format.

@item @@subtitle @var{subtitle}
Typeset @var{subtitle} in the alternative
title page format.

@item @@today@{@}
Insert the current date.
@end table
@tex
% Switch width of first column of tables back to default value
\global\tableindent=.8in
@end tex


@node Command and Variable Index, Concept Index, New Features, Top
@comment  node-name,  next,  previous,  up
@unnumbered Command and Variable Index

This is an alphabetical list of all the @@-commands, assorted Emacs Lisp
functions, and several variables.  To make the list easier to use, the
commands are listed without their preceding @samp{@@}.@refill

@printindex fn


@node Concept Index, , Command and Variable Index, Top
@unnumbered Concept Index

@printindex cp


@summarycontents
@contents
@bye