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[s-roff.git] / tmac / groff_mdoc.reference.man

.\" groff_mdoc.reference.man
.\"
.\"   A complete reference for mdocNG (not finished yet)
.\"
.\" Based on NetBSD's mdoc.samples.7, version 1.21.
.\"
.\"
.\"   Warning: You can't format this file with the old mdoc macros!
.\"
.\"
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.\"     The Regents of the University of California.  All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    notice, this list of conditions and the following disclaimer in the
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.\"    must display the following acknowledgement:
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.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\"     @(#)mdoc.samples.7 8.2 (Berkeley) 12/30/93
.\"
.\" This reference invokes every macro in the package several
.\" times and is guaranteed to give a worst case performance
.\" for an already extremely slow package.
.\"
.
.ds doc-punct-chars \f[R]{.\ ,\ :\ ;\ (\ )\ [\ ]}
.
.
.Dd January 1, 2001
.Os
.Dt MDOC.REFERENCE 7
.
.
.Sh NAME
.
.Nm mdoc.reference
.Nd reference for groff's mdoc implementation
.
.
.Sh SYNOPSIS
.
.Nm man mdoc.reference
.
.
.Sh DESCRIPTION
.
A complete reference for writing
.Ux
manual pages with the
.Nm \-mdoc
macro package; a
.Em content Ns -based
and
.Em domain Ns -based
formatting package for
.Tn GNU
.Xr troff 1 .
Its predecessor, the
.Xr \-man 7
package, addressed page layout leaving the manipulation of fonts and other
typesetting details to the individual author.
In
.Nm \-mdoc ,
page layout macros make up the
.Em "page structure domain"
which consists of macros for titles, section headers, displays and lists
\- essentially items which affect the physical position of text on a
formatted page.
In addition to the page structure domain, there are two more domains, the
.Em manual
domain and the
.Em general
text domain.
The general text domain is defined as macros which perform tasks such as
quoting or emphasizing pieces of text.
The manual domain is defined as macros that are a subset of the day to day
informal language used to describe commands, routines and related to
.Ux
files.
Macros in the manual domain handle command names, command line arguments and
options, function names, function parameters, pathnames, variables, cross
references to other manual pages, and so on.
These domain items have value for both the author and the future user of the
manual page.
It is hoped the consistency gained across the manual set will provide easier
translation to future documentation tools.
.Pp
Throughout the
.Ux
manual pages, a manual entry is simply referred to as a man page, regardless
of actual length and without sexist intention.
.
.
.Sh GETTING STARTED
.
The material presented in the remainder of this document is outlined
as follows:
.
.Bl -enum -width 3n -offset indent
.  It
.  Tn "TROFF IDIOSYNCRASIES"
.
.  Bl -tag -width 2n -compact
.    It "Macro Usage"
.    It "Passing Space Characters in an Argument"
.    It "Trailing Blank Space Characters"
.    It "Escaping Special Characters"
.    It "Other Possible Pitfalls"
.  El
.
.  It
.  Tn "THE ANATOMY OF A MAN PAGE"
.
.  Bl -tag -width 2n -compact
.    It "A Manual Page Template"
.  El
.
.  It
.  Tn "CONVENTIONS"
.
.  It
.  Tn "TITLE MACROS"
.
.  It
.  Tn "INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS"
.
.  Bl -tag -width 2n -compact
.    It "What's in a Name" Ns Ld
.    It "General Syntax"
.  El
.
.  It
.  Tn "MANUAL DOMAIN"
.
.  Bl -tag -width 2n -compact
.    It "Addresses"
.    It "Arguments"
.    It "Configuration Declarations (Section Four Only)"
.    It "Command Modifiers"
.    It "Defined Variables"
.    It "Errno's (Section Two Only)"
.    It "Environment Variables"
.    It "Function Arguments"
.    It "Function Declarations"
.    It "Flags"
.    It "Functions (Library Routines)"
.    It "Function Types"
.    \" .It "Header File (including source code)"
.    It "Interactive Commands"
.    It "Literals"
.    It "Names"
.    It "Options"
.    It "Pathnames"
.    It "Variables"
.    It "Cross References"
.  El
.
.  It
.  Tn "GENERAL TEXT DOMAIN"
.
.  Bl -tag -width 2n -compact
.    It "AT&T Macro"
.    It "BSD Macros"
.    It "UNIX Macro"
.    It "Emphasis Macro"
.    It "Enclosure/Quoting Macros"
.
.    Bl -tag -width 2n -compact
.      It "Angle Bracket Quote/Enclosure"
.      It "Bracket Quotes/Enclosure"
.      It "Double Quote macro/Enclosure"
.      It "Parenthesis Quote/Enclosure"
.      It "Single Quotes/Enclosure"
.      It "Prefix Macro"
.    El
.
.    It "Extended Arguments"
.    It "No\-Op or Normal Text Macro"
.    It "No\-Space Macro"
.    It "Section Cross References"
.    It "Symbolic Macro"
.    It "References and Citations"
.    It "Trade Names (Acronyms and Type Names)"
.  El
.
.  It
.  Tn "PAGE STRUCTURE DOMAIN"
.
.  Bl -tag -width 2n -compact
.    It "Section Headers"
.    It "Paragraphs and Line Spacing"
.    It "Keeps"
.    It "Displays"
.    It "Lists and Columns"
.  El
.
.  It
.  Tn "PREDEFINED STRINGS"
.
.  It
.  Tn "DIAGNOSTICS"
.
.  It
.  Tn "FORMATTING WITH GROFF, TROFF, AND NROFF"
.
.  It
.  Tn "BUGS"
.El
.
.\" XXX
.ne 7
.
.
.Sh TROFF IDIOSYNCRASIES
.
The
.Nm \-mdoc
package attempts to simplify the process of writing a man page.
Theoretically, one should not have to learn the dirty details of
.Tn GNU
.Xr troff 1
to use
.Nm \-mdoc ;
however, there are a few limitations which are unavoidable and best gotten
out of the way.
And, too, be forewarned, this package is
.Em not
fast.
.
.Ss Macro Usage
.
As in
.Tn GNU
.Xr troff 1 ,
a macro is called by placing a
.Ql .\&
(dot character) at the beginning of a line followed by the two-character
(or three-character) name for the macro.
There can be space characters between the dot and the macro name (but
.Em no
tabs).
Arguments may follow the macro separated by spaces (again, no tabs).
It is the dot character at the beginning of the line which causes
.Tn GNU
.Xr troff 1
to interpret the next two (or more) characters as a macro name.
A single starting dot followed by nothing is ignored.
To place a
.Ql .\&
(dot character) at the beginning of an input line in some context other than
a macro invocation, precede the
.Ql .\&
(dot) with the
.Ql \e&
escape sequence.
The
.Ql \e&
translates literally to a zero-width space, and is never displayed in
the output.
.Pp
In general,
.Tn GNU
.Xr troff 1
macros accept an unlimited number of arguments (contrary to other versions
of troff which can't handle more than nine arguments).
In limited cases, arguments may be continued or extended on the next
line (See
.Sx Extended Arguments
below).
Almost all macros handle quoted arguments (see
.Sx Passing Space Characters in an Argument
below).
.Pp
Most of the
.Nm \-mdoc
general text domain and manual domain macros are special in that their
argument lists are
.Em parsed
for callable macro names.
This means an argument on the argument list which matches a general text or
manual domain macro name and is determined to be callable will be executed
or called when it is processed.
In this case the argument, although the name of a macro, is not preceded by
a
.Ql .\&
(dot).
It is in this manner that many macros are nested; for example the
option macro,
.Ql .Op ,
may
.Em call
the flag and argument macros,
.Ql \&Fl
and
.Ql \&Ar ,
to specify an optional flag with an argument:
.
.Bl -tag -xwidth ".Op Fl s Ar bytes" -offset indent
.It Op Fl s Ar bytes
is produced by
.Ql Li ".Op Fl s Ar bytes"
.El
.
.Pp
To prevent a string from being interpreted as a macro name, precede the
string with the escape sequence
.Ql \e& :
.
.Bl -tag -xwidth ".Op \&Fl s \&Ar bytes" -offset indent
.It Op \&Fl s \&Ar bytes
is produced by
.Ql Li ".Op \e&Fl s \e&Ar bytes"
.El
.
.Pp
Here the strings
.Ql \&Fl
and
.Ql \&Ar
are not interpreted as macros.
Macros whose argument lists are parsed for callable arguments are referred
to as
.Em parsed
and macros which may be called from an argument list are referred to as
.Em callable
throughout this document and in the companion quick-reference manual
.Xr groff_mdoc 7 .
This is a technical
.Em faux pas
as almost all of the macros in
.Nm \-mdoc
are parsed, but as it was cumbersome to constantly refer to macros as
being callable and being able to call other macros, the term parsed
has been used.
.
.Ss Passing Space Characters in an Argument
.
Sometimes it is desirable to give as an argument a string containing one or
more blank space characters.
This may be necessary to specify arguments to macros which expect particular
arrangement of items in the argument list.  Additionally, it makes
.Nm \-mdoc
working faster.
For example, the function macro
.Ql .Fn
expects the first argument to be the name of a function and any remaining
arguments to be function parameters.
As
.Tn ANSI\~C
stipulates the declaration of function parameters in the parenthesized
parameter list, each parameter is guaranteed to be at minimum a two word
string.
For example,
.Fa int foo .
.Pp
There are two possible ways to pass an argument which contains
an embedded space.
One way of passing a string containing blank spaces is to use the hard or
unpaddable space character
.Ql \e\  ,
that is, a blank space preceded by the escape character
.Ql \e .
This method may be used with any macro but has the side effect of
interfering with the adjustment of text over the length of a line.
.Xr Troff
sees the hard space as if it were any other printable character and cannot
split the string into blank or newline separated pieces as one would expect.
This method is useful for strings which are not expected to overlap a line
boundary.
An alternative is to use
.Ql \e~ ,
a paddable (i.e.\& stretchable), unbreakable space (this is a
.Tn GNU
.Xr troff 1
extension).
The second method is to enclose the string with double quotes.
.Pp
For example:
.
.Bl -tag -xwidth ".Fn fetch char\ *str" -offset indent
.It Fn fetch char\ *str
is created by
.Ql .Fn fetch char\e *str
.It Fn fetch "char *str"
can also be created by
.Ql .Fn fetch "\\*[q]char *str\\*[q]"
.El
.
.Pp
If the
.Ql \e
before the space resp.\& the double quotes were omitted,
.Ql .Fn
would see three arguments, and the result would be:
.Pp
.Dl Fn fetch char *str
.Pp
For an example of what happens when the parameter list overlaps a newline
boundary, see the
.Sx BUGS
section.
.
.Ss Trailing Blank Space Characters
.
.Xr Troff
can be confused by blank space characters at the end of a line.
It is a wise preventive measure to globally remove all blank spaces
from
.Ao blank-space Ac Ns Ao end-of-line Ac
character sequences.
Should the need arise to force a blank character at the end of a line, it
may be forced with an unpaddable space and the
.Ql \e&
escape character.
For example,
.Ql string\e\ \e& .
.
.Ss Escaping Special Characters
.
Special characters like the newline character
.Ql \en
are handled by replacing the
.Ql \e
with
.Ql \ee
(e.g.\&
.Ql \een )
to preserve the backslash.
.
.Ss Other Possible Pitfalls
.
A warning is emitted when an empty input line is found outside of displays
(see below).
Use
.Ql .sp
instead.
(Well, it is even better to use
.Nm \-mdoc
macros to avoid the usage of low-level commands).
.Pp
Leading spaces will cause a break and are output directly.
Avoid this behaviour if possible.
Similarly, don't use more than one space character between words in an
ordinary text line; contrary to other text formatters, they are
.Em not
replaced with a single space.
.Pp
You can't pass
.Ql \*[q]
directly as an argument.
Use
.Ql \e*[q]
(or
.Ql \e*q )
instead.
.Pp
By default,
.Xr troff 1
inserts two space characters after a punctuation mark closing a sentence
(characters like
.Ql \&)
or
.Ql \&'
are treated transparently, not influencing the sentence-ending behaviour).
To change this, insert
.Ql \e&
before or after the dot:
.
.Bd -literal -offset indent -compact
The
\&.Ql .
character.
\&.Pp
The
\&.Ql \e&.
character.
\&.Pp
\&.No test .
test
\&.Pp
\&.No test.
test
.Ed
.Pp
.
gives
.
.Bd -filled -offset indent
The
.Ql .
character
.Pp
The
.Ql \&.
character.
.Pp
.No test .
test
.Pp
.No test.
test
.Ed
.Pp
.
As can be seen in the first and third line,
.Nm \-mdoc
handles punctuation characters specially in macro arguments.
This will be explained in section
.Sx General Syntax
below.
In the same way, you have to protect trailing full stops of abbreviations
with a trailing zero-width space:
.Ql e.g.\e& .
.Pp
A comment in the source file of a man page can be either started with
.Ql .\e"
on a single line,
.Ql \e"
after some input, or
.Ql \e#
anywhere (the latter is a
.Tn GNU
.Xr troff 1
extension); the rest of such a line is ignored.
.
.
.Sh THE ANATOMY OF A MAN PAGE
.
The body of a man page is easily constructed from a basic template:
.
.Bd -literal -offset indent
\&.\e" /usr/share/misc/mdoc.template:
\&.\e" The following requests are required for all man pages.
\&.
\&.Dd Month day, year
\&.Os OPERATING_SYSTEM [version/release]
\&.Dt DOCUMENT_TITLE [section number] [volume]
\&.Sh NAME
\&.Nm name
\&.Nd one line description of name
\&.Sh SYNOPSIS
\&.Sh DESCRIPTION
\&.
\&.\e" The following requests should be uncommented and
\&.\e" used where appropriate.
\&.\e" .Sh IMPLEMENTATION NOTES
\&.\e" This next request is for sections 2, 3 and 9 function
\&.\e" return values only.
\&.\e" .Sh RETURN VALUES
\&.
\&.\e" This next request is for sections 1, 6, 7, 8 & 9 only
\&.\e" .Sh ENVIRONMENT
\&.\e" .Sh FILES
\&.\e" .Sh EXAMPLES
\&.
\&.\e" This next request is for sections 1, 6, 7, 8 & 9 only
\&.\e"     (command return values (to shell) and
\&.\e"    fprintf/stderr type diagnostics)
\&.\e" .Sh DIAGNOSTICS
\&.
\&.\e" The next request is for sections 2, 3 & 9 error
\&.\e" and signal handling only.
\&.\e" .Sh ERRORS
\&.\e" .Sh SEE ALSO
\&.\e" .Sh STANDARDS
\&.\e" .Sh HISTORY
\&.\e" .Sh AUTHORS
\&.\e" .Sh BUGS
.Ed
.Pp
.
The first items in the template are the macros
.Ql .Dd ,
.Ql .Os ,
and
.Ql .Dt ;
the document date, the operating system the man page or subject source is
developed or modified for, and the man page title (in
.Em upper case )
along with the section of the manual the page belongs in.
These macros identify the page and are discussed below in
.Sx TITLE MACROS .
.Pp
The remaining items in the template are section headers
.Pf ( Li .Sh ) ;
of which
.Sx NAME ,
.Sx SYNOPSIS ,
and
.Sx DESCRIPTION
are mandatory.
The headers are discussed in
.Sx PAGE STRUCTURE DOMAIN ,
after presentation of
.Sx MANUAL DOMAIN .
Several content macros are used to demonstrate page layout macros; reading
about content macros before page layout macros is recommended.
.
.
.Sh CONVENTIONS
.
In the description of all macros below, optional arguments are put into
brackets.
An ellipsis
.Pf ( Ql Ld )
represents zero or more additional arguments.
Alternative values for a parameter are separated with
.Ql | .
If there are alternative values for a mandatory parameter, braces are used
(together with
.Ql | )
to enclose the value set.
Meta-variables are specified within angles.
.Pp
Example:
.
.Bl -tag -width 6n -offset indent
.It Li .Xx Xo
.Aq foo 
.Brq bar1 | bar2
.Op \-test1 Op \-test2 | \-test3
.Ld
.Xc
.El
.
.Pp
Except stated explicitly, all macros are parsed and callable.
.
.
.Sh TITLE MACROS
.
The title macros are part of the page structure domain but are presented
first and separately for someone who wishes to start writing a man page
yesterday.
Three header macros designate the document title or manual page title, the
operating system, and the date of authorship.
These macros are called once at the very beginning of the document and are
used to construct headers and footers only.
.
.Bl -tag -width 6n
.It Li .Dt Xo
.Op Aq document title
.Op Aq section number
.Op Aq volume
.Xc
The document title is the subject of the man page and must be in
.Tn CAPITALS
due to troff limitations.
If omitted,
.Ql Tn UNTITLED
is used.
The section number may be a number in the range
.No 1,\~ Ns Ld Ns ,\~9
or
.Ql unass ,
.Ql draft ,
or
.Ql paper .
If it is specified, and no volume name is given, a default volume name is
used.
A volume name may be arbitrary or one of the following:
.
.Pp
.Bl -column LOCAL -offset indent -compact
.It Li USD   Ta "\*[volume-ds-USD]"
.It Li PS1   Ta "\*[volume-ds-PS1]"
.It Li AMD   Ta "\*[volume-ds-AMD]"
.It Li SMM   Ta "\*[volume-ds-SMM]"
.It Li URM   Ta "\*[volume-ds-URM]"
.It Li PRM   Ta "\*[volume-ds-PRM]"
.It Li KM    Ta "\*[volume-ds-KM]"
.It Li IND   Ta "\*[volume-ds-IND]"
.It Li LOCAL Ta "\*[volume-ds-LOCAL]"
.It Li CON   Ta "\*[volume-ds-CON]"
.El
.Pp
.
For compatibility,
.Ql MMI
can be used for
.Ql IND ,
and
.Ql LOC
for
.Ql LOCAL .
Values from the previous table will specify a new volume name.
If the third parameter is a keyword designating a computer architecture,
its value is appended to the volume name as specified by the second
parameter.  By default, the following architecture keywords are defined:
.
\# we use `No' to avoid hyphenation
.Bd -ragged -offset indent
.No alpha , amiga , arc , arm26 , arm32 , atari , bebox , cobalt , evbsh3 ,
.No hp300 , hpcmips , i386 , luna68k , m68k , mac68k , macppc , mips ,
.No mmeye , mvme68k , news68k , newsmips , next68k , ofppc , pc532 , pmax ,
.No powerpc , prep , sgimips , sh3 , sparc , sparc64 , sun3 , tahoe , vax ,
.No x68k
.Ed
.Pp
.
In the following examples, the left (which is identical to the right) and
the middle part of the manual page header strings are shown.
.
.Bd -ragged
.Bl -tag -xwidth ".Li .Dt\ FOO\ 2\ mac68k" -compact -offset indent
.It Li ".Dt FOO 7"
.Ql FOO(7)
.Ql System Reference Manual
.It Li ".Dt FOO 2 mac68k"
.Ql FOO(2)
.Ql System Programmer's Manual (mac68k Architecture)
.It Li ".Dt FOO \*[q]\*[q] bar"
.Ql FOO
.Ql bar
.El
.Ed
.Pp
.
Local, OS-specific additions might be found in the file
.Pa mdoc.local ;
look for strings named
.Ql volume-ds-XXX
(for the former type) and
.Ql volume-as-XXX
(for the latter type);
.Ql XXX
then denotes the keyword to be used with the
.Ql .Dt
macro.
.Pp
This macro is neither callable nor parsable.
.
.It Li .Os Xo
.Op Aq operating system
.Op Aq release
.Xc
If the first parameter is empty,
.Ql Tn BSD
is used as the default operating system.
This may be overridden in the local configuration file.
In general, the name of the operating system should be the common acronym,
e.g.\&
.Tn BSD
or
.Tn ATT .
The release should be the standard release nomenclature for the system
specified.
In the following table, the possible second arguments for some predefined
operating systems are listed.
Similar to
.Ql .Dt ,
local additions might be defined in
.Pa mdoc.local ;
look for strings named
.Ql operating-system-XXX-YYY ,
where
.Ql XXX
is the acronym for the operating system and
.Ql YYY
the release ID.
.
.Bd -ragged -compact
.Bl -tag -xwidth ".No FreeBSD" -offset indent
.It ATT
7th, 7, III, 3, V, V.2, V.3, V.4
.It BSD
3, 4, 4.1, 4.2, 4.3, 4.3t, 4.3T, 4.3r, 4.3R, 4.4
.It NetBSD
0.8, 0.8a, 0.9, 0.9a, 1.0, 1.0a, 1.1, 1.2, 1.2a, 1.2b, 1.2c, 1.2d, 1.2e,
1.3, 1.3a, 1.4, 1.5
.It FreeBSD
1.0, 1.1, 1.1.5, 1.1.5.1, 2.0, 2.0.5, 2.1, 2.1.5, 2.1.6, 2.1.7, 2.2, 2.2.1,
2.2.2, 2.2.5, 2.2.6, 2.2.7, 2.2.8, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 4.0, 4.1,
4.2, 5.0
.El
.Ed
.Pp
.
For
.Tn ATT ,
an unknown second parameter will be replaced with the string
.Tn UNIX ;
for the other predefined acronyms it will be ignored and a warning message
emitted.
Unrecognized arguments are displayed as given in the page footer.
For instance, a typical footer might be:
.Pp
.Dl .Os BSD 4.3
.Pp
giving
.Ql 4.3\~Berkeley Distribution ,
or for a locally produced set
.Pp
.Dl .Os CS Department
.Pp
which will produce
.Ql CS Department .
.Pp
If the
.Ql .Os
macro is not present, the bottom left corner of the manual page will be
ugly.
.Pp
This macro is neither callable nor parsable.
.
.It Li .Dd Oo
.Aq month
.Aq day ,
.Aq year
.Oc
If
.Ql Dd
has no arguments,
.Ql Epoch
is used for the date string.
If it has exactly three arguments, they are concatenated, separated with
unbreakable space:
.Pp
.Dl .Dd January 25, 2001
.Pp
Otherwise, the current date is used, ignoring the parameters.
.Pp
This macro is neither callable nor parsable.
.El
.
.
.Sh INTRODUCTION OF MANUAL AND GENERAL TEXT DOMAINS
.
.Ss What's in a name Ns Ld
.
The manual domain macro names are derived from the day to day informal
language used to describe commands, subroutines and related files.
Slightly different variations of this language are used to describe the
three different aspects of writing a man page.
First, there is the description of
.Nm \-mdoc
macro request usage.
Second is the description of a
.Ux
command
.Em with
.Nm \-mdoc
macros, and third, the description of a command to a user in the verbal
sense; that is, discussion of a command in the text of a man page.
.Pp
In the first case,
.Xr troff 1
macros are themselves a type of command; the general syntax for a troff
command is:
.
.Bd -filled -offset indent
.Li ".Xx argument1 argument2" Ld
.Ed
.Pp
.
.Ql .Xx
is a macro command or request, and anything following it are arguments to
be processed.
In the second case, the description of a
.Ux
command using the content macros is a bit more involved; a typical
.Sx SYNOPSIS
command line might be displayed as:
.
.Bd -filled -offset indent
.Nm filter
.Op Fl flag
.Ao Ar infile Ac Ao Ar outfile Ac
.Ed
.Pp
.
Here,
.Nm filter
is the command name and the
bracketed string
.Fl flag
is a
.Em flag
argument designated as optional by the option brackets.
In
.Nm \-mdoc
terms,
.Ao Ar infile Ac
and
.Ao Ar outfile Ac
are called
.Em meta arguments ;
in this example, the user has to replace the meta expressions given in angle
brackets with real file names.
Note that in this document meta arguments are used to describe
.Nm \-mdoc
commands; in most man pages, meta variables are not specifically written
with angle brackets.
The macros which formatted the above example:
.
.Bd -literal -offset indent
\&.Nm filter
\&.Op Fl flag
\&.Ao Ar infile Ac Ao Ar outfile Ac
.Ed
.Pp
.
In the third case, discussion of commands and command syntax includes both
examples above, but may add more detail.
The arguments
.Ao Ar infile Ac
and
.Ao Ar outfile Ac
from the example above might be referred to as
.Em operands
or
.Em file arguments .
Some command line argument lists are quite long:
.
.Bd -ragged
.Bl -tag -xwidth ".Nm make" -offset indent -compact
.It Nm make
.Op Fl eiknqrstv
.Op Fl D Ar variable
.Op Fl d Ar flags
.Op Fl f Ar makefile
.Op Fl I Ar directory
.Op Fl j Ar max_jobs
.Op Ar variable=value
.Bk
.Op Ar target Ld
.Ek
.El
.Ed
.Pp
.
Here one might talk about the command
.Nm make
and qualify the argument,
.Ar makefile ,
as an argument to the flag,
.Fl f ,
or discuss the optional file operand
.Ar target .
In the verbal context, such detail can prevent confusion, however the
.Nm \-mdoc
package does not have a macro for an argument
.Em to
a flag.
Instead the
.Ql \&Ar
argument macro is used for an operand or file argument like
.Ar target
as well as an argument to a flag like
.Ar variable .
The make command line was produced from:
.
.Bd -literal -offset indent
\&.Nm make
\&.Op Fl eiknqrstv
\&.Op Fl D Ar variable
\&.Op Fl d Ar flags
\&.Op Fl f Ar makefile
\&.Op Fl I Ar directory
\&.Op Fl j Ar max_jobs
\&.Op Ar variable=value
\&.Bk
\&.Op Ar target Ld
\&.Ek
.Ed
.Pp
.
The
.Ql .Bk
and
.Ql .Ek
macros are explained in
.Sx Keeps .
.
.Ss General Syntax
.
The manual domain and general text domain macros share a similar syntax with
a few minor deviations; most notably,
.Ql .Ar ,
.Ql .Fl ,
.Ql .Nm ,
and
.Ql .Pa
differ only when called without arguments; and
.Ql .Fn
and
.Ql .Xr
impose an order on their argument lists.
All content macros are capable of recognizing and properly handling
punctuation, provided each punctuation character is separated by a leading
space.
If a request is given:
.Pp
.Dl \&.Ar sptr, ptr),
.Pp
The result is:
.Pp
.Dl Ar sptr, ptr),
.Pp
The punctuation is not recognized and all is output in the
font used by
.Ql .Ar .
If the punctuation is separated by a leading white space:
.Pp
.Dl \&.Ar "sptr , ptr ) ,"
.Pp
The result is:
.Pp
.Dl Ar sptr , ptr ) ,
.Pp
The punctuation is now recognized and output in the default font
distinguishing it from the argument strings.
To remove the special meaning from a punctuation character escape it with
.Ql \e& .
.Pp
.Xr Troff
is limited as a macro language, and has difficulty when presented with a
string containing a member of the mathematical, logical or quotation set:
.
.Bd -literal -offset indent-two
{+,\-,/,*,%,<,>,<=,>=,=,==,&,`,',"}
.Ed
.Pp
.
The problem is that
.Xr troff
may assume it is supposed to actually perform the operation or evaluation
suggested by the characters.
To prevent the accidental evaluation of these characters, escape them with
.Ql \e& .
Typical syntax is shown in the first content macro displayed below,
.Ql \&.Ad .
.
.Ss Address Macro
.
The address macro identifies an address construct.
.Pp
.Dl Usage: .Ad Ao address Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Ad\ f1\ ,\ f2\ ,\ f3\ :" -compact -offset 15n
.It Li ".Ad addr1"
.Ad addr1
.It Li ".Ad addr1 ."
.Ad addr1 .
.It Li ".Ad addr1 , file2"
.Ad addr1 , file2
.It Li ".Ad f1 , f2 , f3 :"
.Ad f1 , f2 , f3 :
.It Li ".Ad addr ) ) ,"
.Ad addr ) ) ,
.El
.Pp
.
.Ss Argument Macro
.
The
.Li .Ar
argument macro may be used whenever an argument is referenced.
.Pp
.Dl Usage: .Ar Oo Ao argument Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Ar\ file1\ file2" -compact -offset 15n
.It Li .Ar
.Ar
.It Li ".Ar file1"
.Ar file1
.It Li ".Ar file1 ."
.Ar file1 .
.It Li ".Ar file1 file2"
.Ar file1 file2
.It Li ".Ar f1 f2 f3 :"
.Ar f1 f2 f3 :
.It Li ".Ar file ) ) ,"
.Ar file ) ) ,
.El
.Pp
.
.Ss Configuration Declaration (Section Four Only)
.
The
.Ql .Cd
macro is used to demonstrate a
.Xr config 8
declaration for a device interface in a section four manual.
.Pp
.Dl Usage: .Cd Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Cd\ Xdevice\ le0\ at\ scode?X" -offset 15n
.It Li ".Cd \*[q]device le0 at scode?\*[q]"
\# since .Cd causes a break we use .Nm
.Nm "device le0 at scode?"
.El
.Pp
.
.Ss Command Modifier
.
The command modifier is identical to the
.Ql .Fl
(flag) command with the exception
the
.Ql .Cm
macro does not assert a dash in front of every argument.
Traditionally flags are marked by the preceding dash, however, some commands
or subsets of commands do not use them.
Command modifiers may also be specified in conjunction with interactive
commands such as editor commands.
See
.Sx Flags .
.
.Ss Defined Variables
.
A variable which is defined in an include file is specified by the macro
.Ql .Dv .
.Pp
.Dl Usage: .Dv Ao defined variable Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Dv\ MAXHOSTNAMELEN" -compact -offset 15n
.It Li ".Dv MAXHOSTNAMELEN"
.Dv MAXHOSTNAMELEN
.It Li ".Dv TIOCGPGRP )"
.Dv TIOCGPGRP )
.El
.Pp
.
.Ss Errno's (Section Two Only)
.
The
.Ql .Er
errno macro specifies the error return value for section two library
routines.
The second example below shows
.Ql .Er
used with the
.Ql .Bq
general text domain macro, as it would be used in a section two manual page.
.Pp
.Dl Usage: .Er Ao errno type Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Bq\ Er\ ENOTDIR" -compact -offset 15n
.It Li ".Er ENOENT"
.Er ENOENT
.It Li ".Er ENOENT ) ;"
.Er ENOENT ) ;
.It Li ".Bq Er ENOTDIR"
.Bq Er ENOTDIR
.El
.Pp
.
.Ss Environment Variables
.
The
.Ql .Ev
macro specifies an environment variable.
.Pp
.Dl Usage: .Ev Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Ev\ PRINTER\ )\ )\ ," -compact -offset 15n
.It Li ".Ev DISPLAY"
.Ev DISPLAY
.It Li ".Ev PATH ."
.Ev PATH .
.It Li ".Ev PRINTER ) ) ,"
.Ev PRINTER ) ) ,
.El
.Pp
.
.Ss Function Argument
.
The
.Ql .Fa
macro is used to refer to function arguments (parameters) outside of the
.Sx SYNOPSIS
section of the manual or inside the
.Sx SYNOPSIS
section if the enclosure macros
.Ql .Fo
and
.Ql .Fc
instead of
.Ql .Fn
are used.
.Ql .Fa
may also be used to refer to structure members.
.Pp
.Dl Usage: .Fa Ao function argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Fa\ d_namlen\ )\ )\ ," -compact -offset 15n
.It Li ".Fa d_namlen ) ) ,"
.Fa d_namlen ) ) ,
.It Li ".Fa iov_len"
.Fa iov_len
.El
.Pp
.
.Ss Function Declaration
.
The
.Ql .Fd
macro is used in the
.Sx SYNOPSIS
section with section two or three functions.
It is neither parsable nor callable.
.Pp
.Dl Usage: .Fd Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Fd\ X#include\ <sys/types.h>X" -compact -offset 15n
.It Li ".Fd \*[q]#include <sys/types.h>\*[q]"
.Fd "#include <sys/types.h>"
.El
.Pp
In the
.Sx SYNOPSIS
section a
.Ql .Fd
request causes a line break if a function has already been presented and a
break has not occurred.
This leaves a nice vertical space in between the previous function call and
the declaration for the next function.
.
.Ss Flags
.
The
.Ql .Fl
macro handles command line flags.
It prepends a dash,
.Ql \- ,
to the flag.
For interactive command flags, which are not prepended with a dash, the
.Ql .Cm
(command modifier)
macro is identical, but without the dash.
.Pp
.Dl Usage: .Fl Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Fl\ xyz\ )\ ," -compact -offset 15n
.It Li .Fl
.Fl
.It Li ".Fl cfv"
.Fl cfv
.It Li ".Fl cfv ."
.Fl cfv .
.It Li ".Cm cfv ."
.Cm cfv .
.It Li ".Fl s v t"
.Fl s v t
.It Li ".Fl \- ,"
.Fl \- ,
.It Li ".Fl xyz ) ,"
.Fl xyz ) ,
.It Li ".Fl |"
.Fl |
.El
.Pp
The
.Ql .Fl
macro without any arguments results in a dash representing stdin/stdout.
Note that giving
.Ql .Fl
a single dash will result in two dashes.
.
.Ss Functions (Library Routines)
.
The 
.Ql .Fn
macro is modeled on ANSI C conventions.
.Pp
.Dl Usage: .Fn Ao function Ac Oo Ao parameter Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Fn\ Xint\ alignX\ Xchar\ *ptrX\ ," -compact -offset 15n
.It Li ".Fn getchar"
.Fn getchar
.It Li ".Fn strlen ) ,"
.Fn strlen ) ,
.It Li ".Fn \*[q]int align\*[q] \*[q]char *ptr\*[q] ,"
.Fn "int align" "char *ptr" ,
.El
.Pp
Note that any call to another macro signals the end of the
.Ql .Fn
call (it will insert a closing parenthesis at that point).
.Pp
For functions with many parameters (which is rare), the macros
.Ql .Fo
(function open)
and
.Ql .Fc
(function close)
may be used with
.Ql .Fa
(function argument).
.Pp
Example:
.
.Bd -literal -offset indent
\&.Fo "int res_mkquery"
\&.Fa "int op"
\&.Fa "char *dname"
\&.Fa "int class"
\&.Fa "int type"
\&.Fa "char *data"
\&.Fa "int datalen"
\&.Fa "struct rrec *newrr"
\&.Fa "char *buf"
\&.Fa "int buflen"
\&.Fc
.Ed
.Pp
.
Produces:
.
.Bd -ragged -offset indent
.Fo "int res_mkquery"
.Fa "int op"
.Fa "char *dname"
.Fa "int class"
.Fa "int type"
.Fa "char *data"
.Fa "int datalen"
.Fa "struct rrec *newrr"
.Fa "char *buf"
.Fa "int buflen"
.Fc
.Ed
.Pp
.
In the
.Sx SYNOPSIS
section, the function will always begin at the beginning of line.
If there is more than one function presented in the
.Sx SYNOPSIS
section and a function type has not been given, a line break will occur,
leaving a nice vertical space between the current function name and the one
prior.
.
.Ss Function Type
.
This macro is intended for the
.Sx SYNOPSIS
section.
It may be used anywhere else in the man page without problems, but its main
purpose is to present the function type in kernel normal form for the
.Sx SYNOPSIS
of sections two and three (it causes a page break, allowing the function
name to appear on the next line).
.Pp
.Dl Usage: .Ft Ao type Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Ft\ struct\ stat" -compact -offset 15n
.It Li ".Ft struct stat"
.Ft struct stat
.El
.
.Ss Interactive Commands
.
The
.Ql .Ic
macro designates an interactive or internal command.
.Pp
.Dl Usage: .Ic Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Ic\ setenv\ ,\ unsetenv" -compact -offset 15n
.It Li ".Ic :wq"
.Ic :wq
.It Li ".Ic \*[q]do while {...}\*[q]"
.Ic "do while {...}"
.It Li ".Ic setenv , unsetenv"
.Ic setenv , unsetenv
.El
.
.Ss Literals
.
The
.Ql .Li
literal macro may be used for special characters, variable constants, etc.\&
-- anything which should be displayed as it would be typed.
.Pp
.Dl Usage: .Li Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Li\ cntrl-D\ )\ ,"  -compact -offset 15n
.It Li ".Li \een"
.Li \en
.It Li ".Li M1 M2 M3 ;"
.Li M1 M2 M3 ;
.It Li ".Li cntrl-D ) ,"
.Li cntrl-D ) ,
.It Li ".Li 1024 Ld"
.Li 1024 Ld
.El
.
.Ss Names
.
The
.Ql .Nm
macro is used for the document title or subject name.
It has the peculiarity of remembering the first argument it was called with,
which should always be the subject name of the page.
When called without arguments,
.Ql .Nm
regurgitates this initial name for the sole purpose of making less work for
the author.
Note: A section two or three document function name is addressed with the
.Ql .Nm
in the
.Sx NAME
section, and with
.Ql .Fn
in the
.Sx SYNOPSIS
and remaining sections.
For interactive commands, such as the
.Ql while
command keyword in
.Xr csh 1 ,
the
.Ql .Ic
macro should be used.
While
.Ql .Ic
is nearly identical
to
.Ql .Nm ,
it can not recall the first argument it was invoked with.
.Pp
.Dl Usage: .Nm Oo Ao argument Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Nm\ mdoc.reference" -compact -offset 15n
.It Li ".Nm mdoc.reference"
.Nm mdoc.reference
.It Li ".Nm \e-mdoc"
.Nm \-mdoc
.It Li ".Nm foo ) ) ,"
.Nm foo ) ) ,
.It Li ".Nm :"
.Nm :
.El
.
.Ss Options
.
The
.Ql .Op
macro places option brackets around the any remaining arguments on the
command line, and places any trailing punctuation outside the brackets.
The macros
.Ql .Oc
and
.Ql .Oo
(which produce an opening resp.\& a closing option bracket) may be used
across one or more lines or to specify the exact position of the closing
parenthesis.
.Pp
.Dl Usage: .Op Oo Ao option Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Op\ Fl\ c\ Ar\ objfil\ Op\ Ar\ corfil\ ," -compact -offset 15n
.It Li .Op
.Op
.It Li ".Op Fl k"
.Op Fl k
.It Li ".Op Fl k ) ."
.Op Fl k ) .
.It Li ".Op Fl k Ar kookfile"
.Op Fl k Ar kookfile
.It Li ".Op Fl k Ar kookfile ,"
.Op Fl k Ar kookfile ,
.It Li ".Op Ar objfil Op Ar corfil"
.Op Ar objfil Op Ar corfil
.It Li ".Op Fl c Ar objfil Op Ar corfil ,"
.Op Fl c Ar objfil Op Ar corfil ,
.It Li ".Op word1 word2"
.Op word1 word2
.It Li ".Li .Op Oo Ao option Ac Oc Ld"
.Li .Op Oo Ao options Ac Oc Ld
.El
.Pp
Here a typical example of the
.Ql .Oc
and
.Ql .Oo
macros:
.
.Bd -literal -offset indent
\&.Oo
\&.Op Fl k Ar kilobytes
\&.Op Fl i Ar interval
\&.Op Fl c Ar count
\&.Oc
.Ed
.Pp
.
Produces:
.
.Bd -filled -offset indent
.Oo
.Op Fl k Ar kilobytes
.Op Fl i Ar interval
.Op Fl c Ar count
.Oc
.Ed
.
.Ss Pathnames
.
The
.Ql .Pa
macro formats path or file names.
.Pp
.Dl Usage: .Pa Oo Ao pathname Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Pa\ /tmp/fooXXXXX\ )\ ." -compact -offset 15n
.It Li .Pa
.Pa
.It Li ".Pa /usr/share"
.Pa /usr/share
.It Li ".Pa /tmp/fooXXXXX ) ."
.Pa /tmp/fooXXXXX ) .
.El
.
.Ss Variables
.
Generic variable reference.
.Pp
.Dl Usage: .Va Ao variable Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Va\ Xchar\ sX\ ]\ )\ )\ ," -compact -offset 15n
.It Li ".Va count"
.Va count
.It Li ".Va settimer ,"
.Va settimer ,
.It Li ".Va \*[q]int *prt\*[q] ) :"
.Va "int *prt" ) :
.It Li ".Va \*[q]char s\*[q] ] ) ) ,"
.Va "char s" ] ) ) ,
.El
.
.Ss Manual Page Cross References
.
The
.Ql .Xr
macro expects the first argument to be a manual page name.
The optional second argument, if a string (defining the manual section), is
put into parentheses.
.Pp
.Dl Usage: .Xr Ao man page name Ac Oo Ao section Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Xr\ xinit\ 1x\ ;" -compact -offset 15n
.It Li ".Xr mdoc"
.Xr mdoc
.It Li ".Xr mdoc ,"
.Xr mdoc ,
.It Li ".Xr mdoc 7"
.Xr mdoc 7
.It Li ".Xr xinit 1x ;"
.Xr xinit 1x ;
.El
.
.
.Sh GENERAL TEXT DOMAIN
.
.Ss AT&T Macro
.
.Pp
.Dl Usage: .At Oo Ao version Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .At\ v6\ ." -compact -offset 15n
.It Li .At
.At
.It Li ".At v6 ."
.At v6 .
.El
.Pp
The following values for
.Ao version Ac
are possible:
.Pp
.Dl 32v, v1, v2, v3, v4, v5, v6, v7, V, V.1, V.2, V.3, V.4
.
.Ss BSD Macro
.
.Pp
.Dl "Usage: .Bx" Bro -alpha | -beta | -devel Brc Ld
.Dl "       .Bx" Oo Ao version Ac Oo Ao release Ac Oc Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Bx\ -devel" -compact -offset 15n
.It Li .Bx
.Bx
.It Li ".Bx 4.3 ."
.Bx 4.3 .
.It Li ".Bx \-devel"
.Bx -devel
.El
.Pp
.Ao version Ac
will be prepended to the string
.Ql Bx .
The following values for
.Ao release Ac
are possible:
.Pp
.Dl Reno, reno, Tahoe, tahoe, Lite, lite, Lite2, lite2
.
.Ss NetBSD Macro
.
.Pp
.Dl Usage: .Nx Oo Ao version Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Nx\ 1.4\ ." -compact -offset 15n
.It Li .Nx
.Nx
.It Li ".Nx 1.4 ."
.Nx 1.4 .
.El
.Pp
For possible values of
.Ao version Ac
see the description of the
.Ql .Os
request above in section
.Sx "TITLE MACROS" .
.
.Ss FreeBSD Macro
.
.Pp
.Dl Usage: .Fx Oo Ao version Ac Oc Ld
.Pp
.Bl -tag -xwidth ".Li .Fx\ 2.2\ ." -compact -offset 15n
.It Li .Fx
.Fx
.It Li ".Fx 2.2 ."
.Fx 2.2 .
.El
.Pp
For possible values of
.Ao version Ac
see the description of the
.Ql .Os
request above in section
.Sx "TITLE MACROS" .
.
.Ss UNIX Macro
.
.Pp
.Dl Usage: .Ux Ld
.Pp
.Bl -tag -xwidth ".Li .Ux" -compact -offset 15n
.It Li .Ux
.Ux
.El
.
.Ss Emphasis Macro
.
Text may be stressed or emphasized with the
.Ql .Em
macro.
The usual font for emphasis is italic.
.Pp
.Dl Usage: .Em Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Em\ vide\ infra\ )\ )\ ," -compact -offset 15n
.It Li ".Em does not"
.Em does not
.It Li ".Em exceed 1024 ."
.Em exceed 1024 .
.It Li ".Em vide infra ) ) ,"
.Em vide infra ) ) ,
.El
.\" XXX
.\" The emphasis can be forced across several lines of text by using
.\" the
.\" .Ql \&.Bf
.\" macro discussed in
.\" .Sx Modes
.\" under
.\" .Sx PAGE STRUCTURE DOMAIN .
.\" .Pp
.\" .Bf -emphasis
.\" We are certain the reason most people desire a Harvard MBA
.\" so they can become to be successful philanthropists.  Only
.\" mathematicians and physicists go to graduate school strictly
.\" to acquire infinite wealthy and fame. Its that inifinity
.\" word that does it to them. Ruins them.
.\" .Ef
.
.Ss Enclosure and Quoting Macros
.
The concept of enclosure is similar to quoting.
The object being to enclose one or more strings between a pair of characters
like quotes or parentheses.
The terms quoting and enclosure are used interchangeably throughout this
document.
Most of the one-line enclosure macros end in small letter
.Ql q
to give a hint of quoting, but there are a few irregularities.
For each enclosure macro there is also a pair of open and close macros which
end in small letters
.Ql o
and
.Ql c
respectively.
.Pp
.ne 10
.
.Bd -filled -offset 4n
.Bl -column "quote" "close" "open" "Angle Bracket Enclosure" "`string' or string"
.Em Quote Ta Em Open Ta Em Close Ta Em Function               Ta Em Result
.No .Aq   Ta    .Ao  Ta    .Ac   Ta "Angle Bracket Enclosure" Ta Ao string Ac
.No .Bq   Ta    .Bo  Ta    .Bc   Ta "Bracket Enclosure"       Ta Bo string Bc
.No .Brq  Ta    .Bro Ta    .Brc  Ta "Brace Enclosure"         Ta Bro string Brc
.No .Dq   Ta    .Do  Ta    .Dc   Ta "Double Quote"            Ta Do string Dc
.No       Ta    .Eo  Ta    .Ec   Ta "Enclose String (in XX)"  Ta XXstringXX
.No .Pq   Ta    .Po  Ta    .Pc   Ta "Parenthesis Enclosure"   Ta Po string Pc
.No .Ql   Ta         Ta          Ta "Quoted Literal"          Ta "`string' or string"
.No .Qq   Ta    .Qo  Ta    .Qc   Ta "Straight Double Quote"   Ta Qo string Qc
.No .Sq   Ta    .So  Ta    .Sc   Ta "Single Quote"            Ta So string Sc
.El
.Ed
.Pp
.
.Bl -tag -xwidth ".Li .Ec , .Eo"
.It Li .Ec , .Eo
These macros expect the first argument to be the opening and closing strings
respectively.
.It Li .Ql
The quoted literal macro behaves differently in troff and nroff mode.
If formatted with
.Xr nroff ,
a quoted literal is always quoted.
If formatted with troff, an item is only quoted if the width of the item is
less than three constant width characters.
This is to make short strings more visible where the font change to literal
(constant width) is less noticeable.
.It Li .Pf
The prefix macro suppresses the whitespace between its first and second
argument:
.
.Bl -tag -xwidth ".Li .Pf\ (\ Fa\ name2" -offset indent
.It Li ".Pf ( Fa name2"
.Pf ( Fa name2
.El
.Pp
.
The
.Ql .Ns
macro (see below) performs the analogous suffix function.
.It Li .Ap
The
.Ql .Ap
macro inserts an apostrophe and exits any special text modes, continuing in
.Ql .No
mode.
.El
.Pp
.
Examples of quoting:
.Pp
.
.Bl -tag -xwidth ".Li .Bq\ Em\ Greek\ ,\ French\ ." -compact -offset indent
.It Li .Aq
.Aq
.It Li ".Aq Ar ctype.h ) ,"
.Aq Ar ctype.h ) ,
.It Li .Bq
.Bq
.It Li ".Bq Em Greek , French ."
.Bq Em Greek , French .
.It Li .Dq
.Dq
.It Li ".Dq string abc ."
.Dq string abc .
.It Li ".Dq \'^[A-Z]\'"
.Dq \'^[A-Z]\'
.It Li ".Ql man mdoc"
.Ql man mdoc
.It Li .Qq
.Qq
.It Li ".Qq string ) ,"
.Qq string ) ,
.It Li ".Qq string Ns ),"
.Qq string Ns ),
.It Li .Sq
.Sq
.It Li ".Sq string"
.Sq string
.It Li ".Em or Ap ing"
.Em or Ap ing
.El
.Pp
.
For a good example of nested enclosure macros, see the
.Ql .Op
option macro.
It was created from the same underlying enclosure macros as those presented
in the list above.
The
.Ql .Xo
and
.Ql .Xc
extended argument list macros are discussed below.
.
.Ss No\-Op or Normal Text Macro
.
The macro
.Ql .No
is
can be used in a macro command line for parameters which should
.Em not
be formatted.
Be careful to add
.Ql \e&
to the word
.Ql \&No
if you really want that English word (and not the macro) as a parameter.
.Pp
.Dl Usage: .No Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .No\ test\ Ta\ with\ Ta\ tabs" -compact -offset 15n
.It Li ".No test Ta with Ta tabs"
.No test Ta with Ta tabs
.El
.
.Ss No\-Space Macro
.
The
.Ql .Ns
macro suppresses insertion of a space between the current position and its
first parameter.
For example, it is useful for old style argument lists where there is no
space between the flag and argument:
.Pp
.Dl "Usage:" Ld Ao argument Ac \&Ns Oo Ao argument Ac Oc Ld
.Dl "      " .Ns Ao argument Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Op\ Fl\ I\ Ns\ Ar\ directory" -compact -offset 15n
.It Li ".Op Fl I Ns Ar directory"
.Op Fl I Ns Ar directory
.El
.Pp
Note: The
.Ql .Ns
macro always invokes the
.Ql .No
macro after eliminating the space unless another macro name follows it.
If used as a request (i.e., the second form above in the
.Sq Usage
line,
.Ql .Ns
is identical to
.Ql .No .
.
.Ss Section Cross References
.
The
.Ql .Sx
macro designates a reference to a section header within the same document.
.Pp
.Dl Usage: .Sx Ao section reference Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Sx\ FILES" -offset 15n
.It Li ".Sx FILES"
.Sx FILES
.El
.
.Ss Symbolic
.
The symbolic emphasis macro is generally a boldface macro in either the
symbolic sense or the traditional English usage.
.Pp
.Dl Usage: .Sy Ao symbol Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Sy\ Important\ Notice" -compact -offset 15n
.It Li ".Sy Important Notice"
.Sy Important Notice
.El
.Pp
.
.Ss References and Citations
.
The following macros make a modest attempt to handle references.
At best, the macros make it convenient to manually drop in a subset of
.Em refer
style references.
.Pp
.Bl -tag -width 6n -offset indent -compact
.It Li .Rs
Reference start (does not take arguments).
Causes a line break in the
.Sx "SEE ALSO"
section and begins collection of reference information until the reference
end macro is read.
.It Li .Re
Reference end (does not take arguments).
The reference is printed.
.It Li .%A
Reference author name; one name per invocation.
.It Li .%B
Book title.
.It Li .%C
City/place (not implemented yet).
.It Li .%D
Date.
.It Li .%I
Issuer/publisher name.
.It Li .%J
Journal name.
.It Li .%N
Issue number.
.It Li .%O
Optional information.
.It Li .%P
Page number.
.It Li .%Q
Corporate or foreign author.
.It Li .%R
Report name.
.It Li .%T
Title of article.
.It Li .%V
Volume.
.El
.Pp
Macros beginning with
.Ql %
are not callable but accept multiple arguments in the usual way.
Only the
.Ql .Tn
macro is handled properly as a parameter; other macros will cause strange
output.
.Ql .%B
and
.Ql .%T
can be used outside of the
.Ql .Rs/.Re
environment.
.Pp
Example:
.
.Bd -literal -offset indent
\&.Rs
\&.%A "Matthew Bar"
\&.%A "John Foo"
\&.%T "Implementation Notes on foobar(1)"
\&.%R "Technical Report ABC-DE-12-345"
\&.%Q "Drofnats College, Nowhere"
\&.%D "April 1991"
\&.Re
.Ed
.Pp
produces
.
.Bd -ragged -offset indent
.Rs
.%A "Matthew Bar"
.%A "John Foo"
.%T "Implementation Notes on foobar(1)"
.%R "Technical Report ABC-DE-12-345"
.%Q "Drofnats College, Nowhere"
.%D "April 1991"
.Re
.Ed
.
.Ss Trade Names (or Acronyms and Type Names)
.
The trade name macro prints its arguments in a smaller font.
Its intended use is to imitate a small caps fonts for uppercase acronyms.
.Pp
.Dl Usage: .Tn Ao symbol Ac Ld
.Pp
.Bl -tag -xwidth ".Li .Tn\ ASCII" -compact -offset 15n
.It Li ".Tn DEC"
.Tn DEC
.It Li ".Tn ASCII"
.Tn ASCII
.El
.Pp
.
.Ss Extended Arguments
.
The
.Li .Xo
and
.Li .Xc
macros allow one to extend an argument list on a macro boundary for the
.Ql .It
macro (see below).
Note that
.Li .Xo
and
.Li .Xc
are implemented similarly to all other macros opening and closing an
enclosure (without inserting characters, of course).
This means that the following is true for those macros also.
.Pp
Here is an example of
.Ql .Xo
using the space mode macro to turn spacing off:
.
.Bd -literal -offset indent
\&.Sm off
\&.It Xo Sy I Ar operation
\&.No \een Ar count No \een
\&.Xc
\&.Sm on
.Ed
.Pp
.
produces
.
.Bd -filled -offset indent
.Bl -tag -compact
.Sm off
.It Xo Sy I Ar operation
.No \en Ar count No \en
.Xc
.Sm on
.El
.Ed
.Pp
.
Another one:
.
.Bd -literal -offset indent
\&.Sm off
\&.It Cm S No / Ar old_pattern Xo
\&.No / Ar new_pattern
\&.No / Op Cm g
\&.Xc
\&.Sm on
.Ed
.Pp
.
produces
.Bd -filled -offset indent
.Bl -tag -compact
.Sm off
.It Cm S No \&/ Ar old_pattern Xo
.No \&/ Ar new_pattern
.No \&/ Op Cm g
.Xc
.Sm on
.El
.Ed
.Pp
.
Another example of
.Ql .Xo
and enclosure macros: Test the value of a variable.
.
.Bd -literal -offset indent
\&.It Xo
\&.Ic .ifndef
\&.Oo \e&! Oc Ns Ar variable Oo
\&.Ar operator variable Ld
\&.Oc Xc
.Ed
.Pp
.
produces
.
.Bd -filled -offset indent
.Bl -tag -width flag -compact
.It Xo
.Ic .ifndef
.Oo \&! Oc Ns Ar variable Oo
.Ar operator variable Ld
.Oc Xc
.El
.Ed
.Pp
.
.
.Sh PAGE STRUCTURE DOMAIN
.
.Ss Section Headers
.
The first three
.Ql .Sh
section header macros listed below are required in every man page.
The remaining section headers are recommended at the discretion of the
author writing the manual page.
The
.Ql .Sh
macro is parsed but not generally callable.
It can be used as an argument in a call to
.Ql .Sh
only; it then reactivates the default font for
.Ql .Sh .
.
.Bl -tag -xwidth ".Li .Sh\ DESCRIPTION"
.It Li ".Sh NAME"
The
.Ql Li ".Sh NAME"
macro is mandatory.
If not specified, headers, footers and page layout defaults will not be set
and things will be rather unpleasant.
The
.Sx NAME
section consists of at least three items.
The first is the
.Ql .Nm
name macro naming the subject of the man page.
The second is the name description macro,
.Ql .Nd ,
which separates the subject name from the third item, which is the
description.
The description should be the most terse and lucid possible, as the space
available is small.
.
.It Li ".Sh SYNOPSIS"
The
.Sx SYNOPSIS
section describes the typical usage of the subject of a man page.
The macros required are either
.Ql .Nm ,
.Ql .Cd ,
or
.Ql .Fn
(and possibly
.Ql .Fo ,
.Ql .Fc ,
.Ql .Fd ,
and
.Ql .Ft ) .
The function name macro
.Ql .Fn
is required for manual page sections\~2 and\~3; the command and general name
macro
.Ql .Nm
is required for sections 1, 5, 6, 7, and\~8.
Section\~4 manuals require a
.Ql .Nm ,
.Ql .Fd
or a
.Ql .Cd
configuration device usage macro.
Several other macros may be necessary to produce the synopsis line as shown
below:
.
.Bd -filled -offset indent
.Nm cat
.Op Fl benstuv
.Op Fl
.Ar
.Ed
.Pp
.
The following macros were used:
.Pp
.Dl ".Nm cat"
.Dl ".Op Fl benstuv"
.Dl ".Op Fl"
.Dl .Ar
.
.It Li ".Sh DESCRIPTION"
In most cases the first text in the
.Sx DESCRIPTION
section is a brief paragraph on the command, function or file, followed by a
lexical list of options and respective explanations.
To create such a list, the
.Ql .Bl
(begin list),
.Ql .It
(list item) and
.Ql .El
(end list)
macros are used (see
.Sx Lists and Columns
below).
.El
.Pp
.
The following
.Ql .Sh
section headers are part of the preferred manual page layout and must be
used appropriately to maintain consistency.
They are listed in the order in which they would be used.
.
.Bl -tag -xwidth ".Li .Sh\ ENVIRONMENT"
.It Li ".Sh ENVIRONMENT"
The
.Sx ENVIRONMENT
section should reveal any related environment variables and clues to their
behavior and/or usage.
.It Li ".Sh EXAMPLES"
There are several ways to create examples.
See the
.Sx EXAMPLES
section below for details.
.It Li ".Sh FILES"
Files which are used or created by the man page subject should be listed via
the
.Ql .Pa
macro in the
.Sx FILES
section.
.It Li ".Sh SEE ALSO"
References to other material on the man page topic and cross references to
other relevant man pages should be placed in the
.Sx SEE ALSO
section.
Cross references are specified using the
.Ql .Xr
macro.
Currently
.Xr refer 1
style references are not accommodated.
.Pp
It is recommended that the cross references are sorted on the section
number, and then alphabetically on the names within a section.
.It Li ".Sh STANDARDS"
If the command, library function or file adheres to a specific
implementation such as
.St -p1003.2
or
.St -ansiC
this should be noted here.
If the command does not adhere to any standard, its history should be noted
in the
.Sx HISTORY
section.
.It Li ".Sh HISTORY"
Any command which does not adhere to any specific standards should be
outlined historically in this section.
.It Li ".Sh AUTHORS"
Credits should be placed here.
.It Li ".Sh DIAGNOSTICS"
Diagnostic messages from a command should be placed in this section.
.It Li ".Sh ERRORS"
Specific error handling, especially from library functions (man page
sections\~2 and\~3) should go here.
The
.Ql .Er
macro is used to specify an error (errno).
.It Li ".Sh BUGS"
Blatant problems with the topic go here.
.El
.Pp
.
User-specified
.Ql .Sh
sections may be added; for example, this section was set with:
.
.Bd -literal -offset 15n
\&.Sh PAGE LAYOUT MACROS
.Ed
.
.Ss Paragraphs and Line Spacing
.
.Bl -tag -xwidth ".Li .Pp"
.It Li .Pp
The 
.Ql .Pp
paragraph command may be used to specify a line space where necessary.
The macro is not necessary after a
.Ql .Sh
or
.Ql .Ss
macro or before a
.Ql .Bl
or
.Ql .Bd
macro (which both assert a vertical distance unless the
.Fl compact
flag is given).
.Pp
The macro is neither callable nor parsed and doesn't take arguments.
.El
.
.\" XXX
.
.\" This worked with version one, need to redo for version three
.\" .Pp
.\" .Ds I
.\" .Cw (ax+bx+c) \ is\ produced\ by\ \&
.\" .\".Cw (ax+bx+c) \&.Va_by_) \&_and_\& \&[?/]m_b1_e1_f1[?/]\&
.\" .Cl Cx \t\t
.\" .Li \&.Cx\ (
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Va ax
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Sy \+
.\" .Cx
.\" .Cl Cx \&(\&
.\" .Va ax
.\" .Cx +
.\" .Va by
.\" .Cx +
.\" .Va c )
.\" .Cx \t
.\" .Em is produced by
.\" .Cx \t
.\" .Li \&.Va by
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Sy \+
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Va c )
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Cx
.\" .Cx
.\" .Cw
.\" .De
.\" .Pp
.\" This example shows the same equation in a different format.
.\" The spaces
.\" around the
.\" .Li \&+
.\" signs were forced with
.\" .Li \e :
.\" .Pp
.\" .Ds I
.\" .Cw (ax\ +\ bx\ +\ c) \ is\ produced\ by\ \&
.\" .\".Cw (ax+bx+c) \&.Va_by_) \&_and_\& \&[?/]m_b1_e1_f1[?/]\&
.\" .Cl Cx \t\t
.\" .Li \&.Cx\ (
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Va a
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Sy x
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Cx \e\ +\e\ \e&
.\" .Cx
.\" .Cl Cx \&(\&
.\" .Va a
.\" .Sy x
.\" .Cx \ +\ \&
.\" .Va b
.\" .Sy y
.\" .Cx \ +\ \&
.\" .Va c )
.\" .Cx \t
.\" .Em is produced by
.\" .Cl Cx \t\t
.\" .Li \&.Va b
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Sy y
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Cx \e\ +\e\ \e&
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Va c )
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Cx
.\" .Cx
.\" .Cw
.\" .De
.\" .Pp
.\" The incantation below was
.\" lifted from the
.\" .Xr adb 1
.\" manual page:
.\" .Pp
.\" .Ds I
.\" .Cw \&[?/]m_b1_e1_f1[?/]\& is\ produced\ by
.\" .Cl Cx \t\t
.\" .Li \&.Cx Op Sy ?/
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Nm m
.\" .Cx
.\" .Cl Cx Op Sy ?/
.\" .Nm m
.\" .Ad \ b1 e1 f1
.\" .Op Sy ?/
.\" .Cx \t
.\" .Em is produced by
.\" .Cx \t
.\" .Li \&.Ar \e\ b1 e1 f1
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Op Sy ?/
.\" .Cx
.\" .Cl Cx \t\t
.\" .Li \&.Cx
.\" .Cx
.\" .Cw
.\" .De
.\" .Pp
.
.Ss Keeps
.
The only keep that is implemented at this time is for words.
The macros are
.Ql .Bk
(begin keep)
and
.Ql .Ek
(end keep).
The only option that
.Ql .Bl
accepts currently is
.Fl words
(this is also the default if no option is given) which is useful for
preventing line breaks in the middle of options.
In the example for the make command line arguments (see
.Sx What's in a name ) ,
the keep prevented
.Xr nroff
from placing up the flag and the argument on separate lines.
.Pp
Both macros are neither callable nor parsed.
.Pp
More work needs to be done with the keep macros; specifically, a
.Fl line
option should be added.
.
.Ss Examples and Displays
.
There are six types of displays.
.Pp
.Bl -tag -xwidth ".Li .D1"
.It Li .D1
(This is D-one.)
Display one line of indented text.
This macro is parsed but not callable.
.Pp
.Dl Fl ldghfstru
.Pp
The above was produced by:
.Li ".Dl Fl ldghfstru" .
.
.It Li .Dl
(This is D-ell.)
Display one line of indented
.Em literal
text.
The
.Ql .Dl
example macro has been used throughout this file.
It allows the indentation (display) of one line of text.
Its default font is set to constant width (literal).
.Ql .Dl
is parsed but not callable.
.Pp
.Dl % ls -ldg /usr/local/bin
.Pp
The above was produced by:
.Li ".Dl % ls -ldg /usr/local/bin" .
.
.It Li .Bd
Begin display.
The
.Ql .Bd
display must be ended with the
.Ql .Ed
macro.
It has the following syntax:
.Pp
.Bl -tag -xwidth ".Li .Bd" -offset indent
.It Li .Bd Xo
.Bro \-literal | \-filled | \-unfilled | \-ragged | \-centered Brc
.Oo \-offset Ao string Ac Oc Oo \-compact Oc Xc
.El
.Pp
.
.Bl -tag -xwidth ".Fl file Ao Ar file name Ac " -compact
.It Fl ragged
Fill, but do not adjust the right margin (only left-justify).
.It Fl centered
Center lines between the current left and right margin.
Note that each single line is centered.
.It Fl unfilled
Do not fill; display a block of text as typed, using line breaks as
specified by the user.
This can produce overlong lines without warning messages.
.It Fl filled
Display a filled block.
The block of text is formatted (i.e., the text is justified on both the left
and right side).
.It Fl literal
Display block with literal font (usually fixed-width).
Useful for source code or simple tabbed or spaced text.
.It Fl file Ao Ar file name Ac
The file name following the
.Fl file
flag is read and displayed.
Literal mode is asserted and tabs are set at 8\~constant width character
intervals.
However, any
.Xr troff/ Ns Nm \-mdoc
commands in the file will be processed.
Currently, this feature is not implemented.
.It Fl offset Ao Ar string Ac
If
.Fl offset
is specified with one of the following strings, the string is interpreted to
indicate the level of indentation for the forthcoming block of text:
.
.Pp
.Bl -tag -xwidth ".Ar indent-two" -compact
.It Ar left
Align block on the current left margin; this is the default mode of
.Ql .Bd .
.It Ar center
Supposedly center the block.
At this time unfortunately, the block merely gets left aligned about an
imaginary center margin.
.It Ar indent
Indent by one default indent value or tab.
The default indent value is also used for the
.Ql .D1
and 
.Ql .Dl
macros, so one is guaranteed the two types of displays will line up.
The indentation value is normally set to\~6n or about two thirds of an inch
(six constant width characters).
.It Ar indent-two
Indent two times the default indent value.
.It Ar right
This
.Em left
aligns the block about two inches from the right side of the page.
This macro needs work and perhaps may never do the right thing within
.Xr troff .
.El
.Pp
.
If
.Ao string Ac
is a valid numeric expression instead
.Pf ( Em with a scale indicator other than
.Sq Em u ) ,
use that value for indentation.
The most useful scale indicators are
.Sq m
and
.Sq n ,
specifying the so-called
.Em \&Em
and
.Em "En square" .
This is approximately the width of the letter
.Sq m
resp.\& the letter
.Sq n
of the current font (for nroff output, both scale indicators give the same
values).
If
.Ao string Ac
isn't a numeric expression, it is tested whether it is an
.Nm \-mdoc
macro name, and the default offset value associated with this macro is used.
Finally, if all tests fail,
the width of
.Ao string Ac
(typeset with a fixed-width font) is taken as the offset.
.It Fl compact
Suppress insertion of vertical space before begin of display.
.El
.
.It Li .Ed
End display (doesn't take parameters).
.El
.
.Ss Tagged Lists and Columns
.
There are several types of lists which may be initiated with the
.Ql .Bl
begin-list macro.
Items within the list are specified with the
.Ql .It
item macro, and each list must end with the
.Ql .El
macro.
Lists may be nested within themselves and within displays.
The use of columns inside of lists or lists inside of columns is unproven.
.Pp
In addition, several list attributes may be specified such as the width of a
tag, the list offset, and compactness (blank lines between items allowed or
disallowed).
Most of this document has been formatted with a tag style list
.Pf ( Fl tag ) .
.Pp
It has the following syntax forms:
.Pp
.Bl -tag -xwidth ".Li .Bl" -offset indent -compact
.It Li .Bl Xo
.Bro \-hang | \-ohang | \-tag | \-diag | \-inset Brc
.Oo \-width Ao string Ac Oc Oo \-xwidth Ao command Ac Oc
.Oo \-offset Ao string Ac Oc Oo \-compact Oc Xc
.It Li .Bl Xo
.No \-column Oo \-offset Ao string Ac Oc
.Ao string1 Ac Ao string2 Ac Ld Xc
.It Li .Bl Xo
.Bro \-item | \-enum Oo \-nested Oc | \-bullet | \-hyphen | \-dash Brc
.Oo \-offset Ao string Ac Oc Oo \-compact Oc Xc
.El
.Pp
.
And now a detailed description of the list types.
.
.Pp
.Bl -tag -xwidth ".Fl column" -compact
.It Fl bullet
A bullet list.
.
.Bd -literal -offset indent
\&.Bl -bullet -offset indent -compact
\&.It
Bullet one goes here.
\&.It
Bullet two here.
\&.El
.Ed
.Pp
.
Produces:
.
.Pp
.Bl -bullet -offset indent -compact
.It
Bullet one goes here.
.It
Bullet two here.
.El
.Pp
.
.It Fl dash No ( or Fl hyphen )
A dash list.
.
.Bd -literal -offset indent
\&.Bl -dash -offset indent -compact
\&.It
Dash one goes here.
\&.It
Dash two here.
\&.El
.Ed
.Pp
.
Produces:
.
.Pp
.Bl -dash -offset indent -compact
.It
Dash one goes here.
.It
Dash two here.
.El
.Pp
.
.It Fl enum
An enumerated list.
.
.Bd -literal -offset indent
\&.Bl -enum -offset indent -compact
\&.It
Item one goes here.
\&.It
And item two here.
\&.El
.Ed
.Pp
.
The result:
.
.Pp
.Bl -enum -offset indent -compact
.It
Item one goes here.
.It
And item two here.
.El
.Pp
.
If you want to nest enumerated lists, use the
.Fl nested
flag (starting with the second-level list):
.
.Bd -literal -offset indent
\&.Bl -enum -offset indent -compact
\&.It
Item one goes here
\&.Bl -enum -nested -compact
\&.It
Item two goes here.
\&.It
And item three here.
\&.El
\&.It
And item four here.
\&.El
.Ed
.Pp
.
Result:
.
.Pp
.Bl -enum -offset indent -compact
.It
Item one goes here.
.Bl -enum -nested -compact
.It
Item two goes here.
.It
And item three here.
.El
.It
And item four here.
.El
.Pp
.
.It Fl item
A list of type
.Fl item
without list markers.
.
.Bd -literal -offset indent
\&.Bl -item -offset indent
\&.It
Item one goes here.
Item one goes here.
Item one goes here.
\&.It
Item two here.
Item two here.
Item two here.
\&.El
.Ed
.Pp
.
Produces:
.
.Pp
.Bl -item -offset indent
.It
Item one goes here.
Item one goes here.
Item one goes here.
.It
Item two here.
Item two here.
Item two here.
.El
.Pp
.
.It Fl tag
A list with tags.
Use
.Fl width
or
.Fl xwidth
to specify the tag width.
.
.Pp
.Bl -tag -width "PPID" -compact -offset indent
.It SL
sleep time of the process (seconds blocked)
.It PAGEIN
number of disk
.Tn I/O Ns 's
resulting from references by the process
to pages not loaded in core.
.It UID
numerical user-id of process owner
.It PPID
numerical id of parent of process priority
(non-positive when in non-interruptible wait)
.El
.Pp
.
The raw text:
.
.Bd -literal -offset indent
\&.Bl -tag -width "PPID" -compact -offset indent
\&.It SL
sleep time of the process (seconds blocked)
\&.It PAGEIN
number of disk
\&.Tn I/O Ns 's
resulting from references by the process
to pages not loaded in core.
\&.It UID
numerical user-id of process owner
\&.It PPID
numerical id of parent of process priority
(non-positive when in non-interruptible wait)
\&.El
.Ed
.Pp
.
.It Fl diag
Diag lists create section-four diagnostic lists and are similar to inset
lists except callable macros are ignored.
This list type can't be nested; the flags
.Fl offset
and
.Fl compact
are ignored
.Pf ( Fl width
resp.\&
.Fl xwidth
are not meaningful in this context).
.Pp
Example:
.
.Bd -literal -offset indent
\&.Bl -diag
\&.It You can't use Sy here.
The message says all.
\&.El
.Ed
.Pp
.
produces
.
.Pp
.Sy "You can't use Sy here" . "\ " No "The message says all" .
.Pp
.
.It Fl hang
A list with hanging tags.
.
.Bl -hang -offset indent
.It Em Hanged
labels appear similar to tagged lists when the
label is smaller than the label width.
.It Em Longer hanged list labels
blend in to the paragraph unlike
tagged paragraph labels.
.El
.Pp
And the unformatted text which created it:
.
.Bd -literal -offset indent
\&.Bl -hang -offset indent
\&.It Em Hanged
labels appear similar to tagged lists when the
label is smaller than the label width.
\&.It Em Longer hanged list labels
blend in to the paragraph unlike
tagged paragraph labels.
\&.El
.Ed
.Pp
.
.It Fl ohang
Lists with overhanging tags don't use indentation for the items; tags are
written to a separate line.
.Pp
.Bl -ohang -offset indent
.It Sy SL
sleep time of the process (seconds blocked)
.It Sy PAGEIN
number of disk
.Tn I/O Ns 's
resulting from references by the process
to pages not loaded in core.
.It Sy UID
numerical user-id of process owner
.It Sy PPID
numerical id of parent of process priority
(non-positive when in non-interruptible wait)
.El
.Pp
.
The raw text:
.
.Bd -literal -offset indent
\&.Bl -ohang -offset indent
\&.It Sy SL
sleep time of the process (seconds blocked)
\&.It Sy PAGEIN
number of disk
\&.Tn I/O Ns 's
resulting from references by the process
to pages not loaded in core.
\&.It Sy UID
numerical user-id of process owner
\&.It Sy PPID
numerical id of parent of process priority
(non-positive when in non-interruptible wait)
\&.El
.Ed
.Pp
.
.It Fl inset
Here is an example of inset labels:
.Bl -inset -offset indent
.It Em Tag
The tagged list (also called a tagged paragraph)
is the most common type of list used in the
Berkeley manuals.
Use a
.Fl width
attribute as described below.
.It Em Diag
Diag lists create section four diagnostic lists
and are similar to inset lists except callable
macros are ignored.
.It Em Hang
Hanged labels are a matter of taste.
.It Em Ohang
Overhanging labels are nice when space is constrained.
.It Em Inset
Inset labels are useful for controlling blocks of
paragraphs and are valuable for converting
.Nm \-mdoc
manuals to other formats.
.El
.Pp
Here is the source text which produced the above example:
.
.Bd -literal -offset indent
\&.Bl -inset -offset indent
\&.It Em Tag
The tagged list (also called a tagged paragraph)
is the most common type of list used in the
Berkeley manuals.
\&.It Em Diag
Diag lists create section four diagnostic lists
and are similar to inset lists except callable
macros are ignored.
\&.It Em Hang
Hanged labels are a matter of taste.
\&.It Em Ohang
Overhanging labels are nice when space is constrained.
\&.It Em Inset
Inset labels are useful for controlling blocks of
paragraphs and are valuable for converting
\&.Nm \-mdoc
manuals to other formats.
\&.El
.Ed
.Pp
.
.It Fl column
This list type generates multiple columns.
The number of columns and the width of each column is determined by the
arguments to the
.Fl column
list.
Each
.Ql .It
argument is parsed to make a row, each column within the row is a separate
argument separated by a tab or the
.Ql .Ta
macro.
.Pp
The table:
.
.Bl -column -offset indent String Nroff Troff
.It Sy String Ta Sy Nroff Ta Sy Troff
.It Li <= Ta <= Ta \*(<=
.It Li >= Ta >= Ta \*(>=
.El
.Pp
.
was produced by:
.
.Bd -literal -offset indent
\&.Bl -column -offset indent String Nroff Troff
\&.It Sy String Ta Sy Nroff Ta Sy Troff
\&.It Li <= Ta <= Ta \e*(<=
\&.It Li >= Ta >= Ta \e*(>=
\&.El
.Ed
.El
.Pp
.
\#
\#=====================================================================
\#
Other keywords:
.
.Bl -tag -xwidth ".Fl width Ar \&Fl" -offset indent
.It Fl width Ar "\&Fl"
sets the width to the default width for a flag.
All callable
macros have a default width value.
The
.Ql \&.Fl ,
value is presently
set to ten constant width characters or about five sixth of
an inch.
.It Fl width Ar "24n"
sets the width to 24 constant width characters or about two
inches.
The
.Ql n
is absolutely necessary for the scaling to work correctly.
.It Fl width Ar "ENAMETOOLONG"
sets width to the constant width length of the
string given.
.It Fl width Ar "\\*qint mkfifo\\*q"
again, the width is set to the constant width of the string
given.
.El
.Pp
If a width is not specified for the tag list type, the first
time
.Ql \&.It
is invoked, an attempt is made to determine an appropriate
width.
If the first argument to
.Ql ".It"
is a callable macro, the default width for that macro will be used
as if the macro name had been supplied as the width.
However,
if another item in the list is given with a different callable
macro name, a new and nested list is assumed.
This effectively
means that
.Fl width
is required for the tag list type.
.
.Sh PREDEFINED STRINGS
The following strings are predefined as may be used by
preceding with the troff string interpreting sequence
.Ql \&\e*(xx
where
.Em xx
is the name of the defined string or as
.Ql \&\e*x
where
.Em x
is the name of the string.
The interpreting sequence may be used any where in the text.
.Pp
.Bl -column "String " "Nroff " "Troff " -offset indent
.It Sy "String  Nroff   Troff"
.It Li "<=" Ta \&<\&= Ta \*(<=
.It Li ">=" Ta \&>\&= Ta \*(>=
.It Li "Rq" Ta "''" Ta \*(Rq
.It Li "Lq" Ta "``" Ta \*(Lq
.It Li "ua" Ta ^ Ta \*(ua
.It Li "aa" Ta ' Ta \*(aa
.It Li "ga" Ta \` Ta \*(ga
.\" .It Li "sL" Ta ` Ta \*(sL
.\" .It Li "sR" Ta ' Ta \*(sR
.It Li "q" Ta \&" Ta \*q
.It Li "Pi" Ta pi Ta \*(Pi
.It Li "Ne" Ta != Ta \*(Ne
.It Li "Le" Ta <= Ta \*(Le
.It Li "Ge" Ta >= Ta \*(Ge
.It Li "Lt" Ta < Ta \*(Gt
.It Li "Gt" Ta > Ta \*(Lt
.It Li "Pm" Ta +\- Ta \*(Pm
.It Li "If" Ta infinity Ta \*(If
.It Li "Na" Ta \fINaN\fP Ta \*(Na
.It Li "Ba" Ta \fR\&|\fP Ta \*(Ba
.El
.Pp
.Sy Note :
The string named
.Ql q
should be written as
.Ql \e*q
since it is only one char.
.Sh DIAGNOSTICS
The debugging facilities for
.Nm \-mdoc
are limited, but can help detect subtle errors such
as the collision of an argument name with an internal
register or macro name.
(A what?)
A register is an arithmetic storage class for
.Xr troff
with a one or two character name.
All registers internal to
.Nm \-mdoc
for
.Xr troff
and
.Xr ditroff
are two characters and
of the form <upper_case><lower_case> such as
.Ql \&Ar ,
<lower_case><upper_case> as
.Ql \&aR
or
<upper or lower letter><digit> as
.Ql \&C\&1 .
And adding to the muddle,
.Xr troff
has its own internal registers all of which are either
two lower case characters or a dot plus a letter or meta-character
character.
In one of the introduction examples, it was shown how to
prevent the interpretation of a macro name with the escape sequence
.Ql \e& .
This is sufficient for the internal register names also.
.Pp
.\" Every callable macro name has a corresponding register
.\" of the same name (<upper_case><lower_case>).
.\" There are also specific registers which have
.\" been used for stacks and arrays and are listed in the
.\" .Sx Appendix .
.\" .Bd -ragged -offset 4n
.\" [A-Z][a-z]  registers corresponding to macro names (example ``Ar'')
.\" [a-z][A-Z]  registers corresponding to macro names (example ``aR'')
.\" C[0-9]              argument types (example C1)
.\" O[0-9]              offset stack (displays)
.\" h[0-9]              horizontal spacing stack (lists)
.\" o[0-9]              offset (stack) (lists)
.\" t[0-9]              tag stack (lists)
.\" v[0-9]              vertical spacing stack (lists)
.\" w[0-9]              width tag/label stack
.\" .Ed
.\" .Pp
If a non-escaped register name is given in the argument list of a request
unpredictable behavior will occur.
In general, any time huge portions
of text do not appear where expected in the output, or small strings
such as list tags disappear, chances are there is a misunderstanding
about an argument type in the argument list.
Your mother never intended for you to remember this evil stuff -- so here
is a way to find out whether or not your arguments are valid: The
.Ql \&.Db
(debug)
macro displays the interpretation of the argument list for most
macros.
Macros such as the
.Ql \&.Pp
(paragraph)
macro do not contain debugging information.
All of the callable macros do,
and it is strongly advised whenever in doubt,
turn on the
.Ql \&.Db
macro.
.Pp
.Dl Usage: \&.Db [on | off]
.Pp
An example of a portion of text with
the debug macro placed above and below an
artificially created problem (a flag argument
.Ql \&aC
which should be
.Ql \e&aC
in order to work):
.
.Bd -literal -offset indent
\&.Db on
\&.Op Fl aC Ar file )
\&.Db off
.Ed
.Pp
The resulting output:
.
.Bd -literal -offset indent
DEBUGGING ON
DEBUG(argv) MACRO: `.Op'  Line #: 2
        Argc: 1  Argv: `Fl'  Length: 2
        Space: `'  Class: Executable
        Argc: 2  Argv: `aC'  Length: 2
        Space: `'  Class: Executable
        Argc: 3  Argv: `Ar'  Length: 2
        Space: `'  Class: Executable
        Argc: 4  Argv: `file'  Length: 4
        Space: ` '  Class: String
        Argc: 5  Argv: `)'  Length: 1
        Space: ` '  Class: Closing Punctuation or suffix
        MACRO REQUEST: .Op Fl aC Ar file )
DEBUGGING OFF
.Ed
.Pp
The first line of information tells the name of the calling
macro, here
.Ql \&.Op ,
and the line number it appears on.
If one or more files are involved
(especially if text from another file is included) the line number
may be bogus.
If there is only one file, it should be accurate.
The second line gives the argument count, the argument
.Pq Ql \&Fl
and its length.
If the length of an argument is two characters, the
argument is tested to see if it is executable (unfortunately, any
register which contains a non-zero value appears executable).
The third line gives the space allotted for a class, and the
class type.
The problem here is the argument aC should not be
executable.
The four types of classes are string, executable, closing
punctuation and opening punctuation.
The last line shows the entire
argument list as it was read.
In this next example, the offending
.Ql \&aC
is escaped:
.
.Bd -literal -offset indent
\&.Db on
\&.Em An escaped \e&aC
\&.Db off
.Ed
.
.Bd -literal -offset indent
DEBUGGING ON
DEBUG(fargv) MACRO: `.Em'  Line #: 2
        Argc: 1  Argv: `An'  Length: 2
        Space: ` '  Class: String
        Argc: 2  Argv: `escaped'  Length: 7
        Space: ` '  Class: String
        Argc: 3  Argv: `aC'  Length: 2
        Space: ` '  Class: String
        MACRO REQUEST: .Em An escaped &aC
DEBUGGING OFF
.Ed
.Pp
The argument
.Ql \e&aC
shows up with the same length of 2 as the
.Ql \e&
sequence produces a zero width, but a register
named
.Ql \e&aC
was not found and the type classified as string.
.Pp
Other diagnostics consist of usage statements and are self explanatory.
.Sh GROFF, TROFF AND NROFF
The
.Nm \-mdoc
package does not need compatibility mode with
.Xr groff .
.Pp
The package inhibits page breaks, and the headers and footers
which normally occur at those breaks with
.Xr nroff ,
to make the manual more efficient for viewing on-line.
At the moment,
.Xr groff
with
.Fl T Ns Ar ascii
does eject the imaginary remainder of the page at end of file.
The inhibiting of the page breaks makes
.Xr nroff Ns 'd
files unsuitable for hardcopy.
There is a register named
.Ql \&cR
which can be set to zero in the site dependent style file
.Pa /usr/\:src/\:share/\:tmac/\:doc-nroff
to restore the old style behavior.
.Sh FILES
.Bl -tag -width /usr/share/misc/mdoc.template -compact
.It Pa /usr/share/tmac/tmac.doc
manual macro package
.It Pa /usr/share/misc/mdoc.template
template for writing a man page
.El
.Sh SEE ALSO
.Xr mdoc 7 ,
.Xr man 1 ,
.Xr troff 1
.Sh BUGS
Undesirable hyphenation on the dash of a flag
argument is not yet resolved, and causes
occasional mishaps in the
.Sx DESCRIPTION
section.
(line break on the hyphen).
.Pp
Predefined strings are not declared in documentation.
.Pp
Section 3f has not been added to the header routines.
.Pp
.Ql \&.Nm
font should be changed in
.Sx NAME
section.
.Pp
.Ql \&.Fn
needs to have a check to prevent splitting up
if the line length is too short.
Occasionally it
separates the last parenthesis, and sometimes
looks ridiculous if a line is in fill mode.
.Pp
The method used to prevent header and footer page
breaks (other than the initial header and footer) when using
nroff occasionally places an unsightly partially filled line (blank)
at the would be bottom of the page.
.Pp
If the outer-most list definition doesn't have a
.Fl width
argument, the
.Ql ".It"
elements of inner lists may not work (producing a list where
each successive element
.Sq walks
to the right).
.Pp
The list and display macros to not do any keeps
and certainly should be able to.
.\" Note what happens if the parameter list overlaps a newline
.\" boundary.
.\" to make sure a line boundary is crossed:
.\" .Bd -literal
.\" \&.Fn struct\e\ dictionarytable\e\ *dictionarylookup struct\e\ dictionarytable\e\ *tab[]
.\" .Ed
.\" .Pp
.\" produces, nudge nudge,
.\" .Fn struct\ dictionarytable\ *dictionarylookup char\ *h struct\ dictionarytable\ *tab[] ,
.\" .Fn struct\ dictionarytable\ *dictionarylookup char\ *h struct\ dictionarytable\ *tab[] ,
.\" nudge
.\" .Fn struct\ dictionarytable\ *dictionarylookup char\ *h struct\ dictionarytable\ *tab[] .
.\" .Pp
.\" If double quotes are used, for example:
.\" .Bd -literal
.\" \&.Fn \*qstruct dictionarytable *dictionarylookup\*q \*qchar *h\*q \*qstruct dictionarytable *tab[]\*q
.\" .Ed
.\" .Pp
.\" produces, nudge nudge,
.\" .Fn "struct dictionarytable *dictionarylookup" "char *h" "struct dictionarytable *tab[]" ,
.\" nudge
.\" .Fn "struct dictionarytable *dictionarylookup" "char *h" "struct dictionarytable *tab[]" ,
.\" nudge
.\" .Fn "struct dictionarytable *dictionarylookup" "char *h" "struct dictionarytable *tab[]" .
.\" .Pp
.\" Not a pretty sight...
.\" In a paragraph, a long parameter containing unpaddable spaces as
.\" in the former example will cause
.\" .Xr troff
.\" to break the line and spread
.\" the remaining words out.
.\" The latter example will adjust nicely to
.\" justified margins, but may break in between an argument and its
.\" declaration.
.\" In
.\" .Xr nroff
.\" the right margin adjustment is normally ragged and the problem is
.\" not as severe.