small corrections / a forgived string ...

[midnight-commander.git] / doc / mcedit.1.in

.TH mcedit 1 "30 January 1997"
.\"SKIP_SECTION"
.SH NAME
mcedit \- Full featured terminal text editor for Unix-like systems.
.\"SKIP_SECTION"
.SH USAGE
.B mcedit
[[+number] file [\-bcCdfhstVx?]]
.SH DESCRIPTION
.LP
Mcedit is a link to 
.B mc,
the Midnight Commander, forcing it 
to immediately start its internal editor. The editor is a terminal 
version of the 
.B cooledit 
standalone X Window editor.
.\".\"DONT_SPLIT"
.SH OPTIONS
.TP
.I "+number"
Go  to the line specified by number (do not insert
a space between the "+" sign and the number).
.TP
.I "\-b"
Forces black and white display.
.TP
.I "\-c"
Force color mode on terminals where 
.B mcedit 
defaults to black and white.
.TP
.I "\-C <keyword>=<FGcolor>,<BGcolor>:<keyword>= ..."
Used to specify a different color set, where 
.I keyword 
is one of normal, selected, marked, markselect, errors,
reverse menu, menusel, menuhot, menuhotsel and gauge. The colors
are optional and are one of black, gray, red, brightred, green,
brightgreen, brown, yellow, blue, brightblue, magenta,
brightmagenta, cyan, brightcyan, lightgray and white.
See the 
.B Colors 
section in 
.B mc.1 
for more information.
.TP
.I "\-d"
Disables mouse support.
.TP
.I "\-f"
Displays the compiled-in search paths for Midnight Commander files.
.TP
.I "\-t"
Used only if the code was compiled with Slang and terminfo: it makes
the Midnight Commander use the value of the 
.B TERMCAP
variable for the terminal information instead of the information on
the system wide terminal database
.TP
.I "\-V"
Displays the version of the program.
.TP
.I "\-x"
Forces xterm mode.  Used when running on xterm-capable terminals (two
screen modes, and able to send mouse escape sequences).
.PP
.SH Features
The internal file editor provides most of the features of common full
screen editors.  It has an extendable file size limit of sixteen megabytes
and edits binary files flawlessly.  The features it presently supports
are: Block copy, move, delete, cut, paste;
.I "key for key undo"; 
pull-down
menus; file insertion; macro definition; regular expression
search and replace (and our own scanf-printf search and
replace); shift-arrow MSW-MAC text highlighting (for the
linux console only); insert-overwrite toggle; word-wrap;
a variety of tabbing options; syntax highlighting for
various file types; and an option
to pipe text blocks through shell commands like indent and
ispell.
.PP
.SH Keys
The editor is very easy to use and requires no tutoring.
To see what keys do what, just consult the appropriate
pull-down menu. Other keys are: Shift movement
keys do text highlighting (Linux console only). 
.B Ctrl-Ins 
copies to the file 
.BR ~/.mc/cedit/cooledit.clip,
and 
.B Shift-Ins 
pastes from 
.BR ~/.mc/cedit/cooledit.clip. 
.B Shift-Del 
cuts to 
.BR ~/.mc/cedit/cooledit.clip, 
and 
.B Ctrl-Del 
deletes highlighted text - all linux console only.  Mouse highlighting
also works, and you can override the mouse as usual by holding down
the shift key while dragging the mouse to let normal terminal mouse
highlighting work.
.PP
The completion key (usually
.B "Alt-Tab"
or
.BR "Espace-Tab")
completes the word under the cursor using the words used earlier in the
file.
.PP
To define a macro, press 
.B Ctrl-R 
and then type out the key
strokes you want to be executed. Press 
.B Ctrl-R 
again when finished. You can then assign the macro to any key you
like by pressing that key. The macro is executed when you press
.B Ctrl-A 
and then the assigned key. The macro is also executed if
you press Meta, Ctrl, or Esc and the assigned key, provided that the
key is not used for any other function. Once defined, the macro
commands go into the file 
.BR ~/.mc/cedit/cooledit.macros. 
Do NOT edit this file if you are going to use macros again in the same
editing session, because
.B Mcedit 
caches macro key defines in memory. 
.B Mcedit 
now overwrites a macro if a macro with the same key already exists,
so you won't have to edit this file. You will also have to restart
other running editors for macros to take effect.

.B F19 
will format C code when it is highlighted.  An executable file called 
.B ~/.mc/cedit/edit.indent.rc 
will be created for you from the default template.  Feel free to edit it
if you need.
.PP
.B C-p 
will run ispell on a block of text in a similar way.  The script file
will be called
.B ~/.mc/cedit/edit.spell.rc
.
.PP
.SH Redefining Keys
Keys may be redefined from the Midnight Commander options
menu.
.PP
.SH SYNTAX HIGHLIGHTING
As of version 3.6.0, \fBcooledit\fP has syntax highlighting.  This means
that keywords and contexts (like C comments, string constants, etc)
are highlighted in different colors.  The following section explains
the format of the file \fB~/.mc/cedit/Syntax\fP.

The file \fB~/.mc/cedit/Syntax\fP is rescanned on opening of a any new
editor file. The file contains rules for highlighting, each of which is
given on a separate line, and define which keywords will be highlighted
to what color. The file is also divided into sections, each beginning
with a line with the \fBfile\fP command, followed by a regular
expression. The regular expression dictates the file name that that set
of rules applies to. Following this is a description to be printed on the
left of the editor window explaining the file type to the user. A third
optional argument is a regular expression to match the first line of
text of the file. If either the file name matches, or the first line of text,
then those rules will be loaded.

A section ends with the start of a new section. Each section is divided
into contexts, and each context contains rules. A context is a scope
within the text that a particular set of rules belongs to. For instance,
the region within a C style comment (i.e. between \fB/*\fP and \fB*/\fP)
has its own color. This is a context, although it will have no further
rules inside it because there is probably nothing that we want
highlighted within a C comment.

A trivial C programming section might look like this:
.PP
.nf
file .\\*\\\\.c C\\sProgram\\sFile (#include|/\\\\\\*)

wholechars abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_

# default colors
context default
  keyword  whole  if       24
  keyword  whole  else     24
  keyword  whole  for      24
  keyword  whole  while    24
  keyword  whole  do       24
  keyword  whole  switch   24
  keyword  whole  case     24
  keyword  whole  static   24
  keyword  whole  extern   24
  keyword         {        14
  keyword         }        14
  keyword         '*'      6 

# C comments
context /\\* \\*/ 22

# C preprocessor directives
context linestart # \\n 18
  keyword  \\\\\\n  24

# C string constants
context " " 6
  keyword  %d    24
  keyword  %s    24
  keyword  %c    24
  keyword  \\\\"   24
.fi
.PP
Each context starts with a line of the form:
.br
\fBcontext\fP [\fBexclusive\fP] [\fBwhole\fP|\fBwholeright\fP|\fBwholeleft\fP] 
[\fBlinestart\fP] \fIdelim\fP [\fBlinestart\fP] \fIdelim\fP [\fIforeground\fP] [\fIbackground\fP]
.br

One exception is the first context. It must start with the command
.br
\fBcontext\fP \fBdefault\fP [\fIforeground\fP] [\fIbackground\fP]
.br
or else \fBcooledit\fP will return an error.

The \fBlinestart\fP option dictates that \fIdelim\fP must start at
the beginning of a line.

The \fBwhole\fP option tells that delim must be a whole word. What
constitutes a whole word are a set of characters that can be
changed at any point in the file with the \fBwholechars\fP
command. The \fBwholechars\fP command at the top just sets the
set exactly to its default and could therefore have been omitted. To
specify that a word must be whole on the left only, you can use
the \fBwholeleft\fP option, and similarly on the right. The left and
right set of characters can be set separately with,
.br
\fBwholechars\fP [\fBleft\fP|\fBright\fP] \fIcharacters\fP

The \fBexclusive\fP option causes the text between the delimiters to be
highlighted, but not the delimiters themselves.

Each rule is a line of the form:
.br
\fBkeyword\fP [\fBwhole\fP|\fBwholeright\fP|\fBwholeleft\fP] [\fBlinestart\fP] 
\fIstring\fP \fIforeground\fP [\fIbackground\fP]
.br

Context or keyword strings are interpreted, so that you can include
tabs and spaces with the sequences \\t and \\s.  Newlines and the \\ are
specified with \\n and \\\\ respectively.  Since whitespace is used as a
separator, it may not be used as is.  Also, \\* must be used to specify
a *.  The * itself is a wildcard that matches any length of characters.
For example,
.nf
  keyword         '*'      6 
.fi
colors all C single character constants green. You could also have
used
.nf
  keyword         "*"      6 
.fi
to color string constants, except that the matched string may not cross
newlines. \fIThe wildcard may be used within context delimiters as
well\fP, but you \fBcannot have a wildcard as the last or first character\fP.

Important to note is the line
.nf
  keyword  \\\\\\n  24
.fi
This line defines a keyword containing the \\ and newline characters.
Because keywords have a higher precedence than context delimiters, this
keyword prevents the context from ending at the end of a line if the
line ends in a \\ thus allowing C preprocessor directive to continue
across multiple lines.

The colors themselves are numbered 0 to 26 and are explained below in
\fBFURTHER BEHAVIORAL OPTIONS\fP. You can also use \fBany\fP of the named
colors specified in \fB/usr/lib/X11/rgb.txt\fP, though only one word
versions of them. It is better to stick to the numerical colors
to limit use of the color palette.

Comments may be included on a line of there own and begin with
a #.

Because of the simplicity of the implementation, there are a few
intricacies that will not be coped with correctly but these are a minor
irritation. On the whole, a broad spectrum of quite complicated
situations are handled with these simple rules. It is a good idea to
take a look at the syntax file to see some of the nifty tricks you can
do with a little imagination. If you can't get by with the rules I have
coded, and you think you have a rule that would be useful, please email
me with your request. However, do not ask for regular expression
support, because this is flatly impossible.

A useful hint is to work with as much as possible with the things
you \fIcan\fP do rather than try to do things that this
implementation can't cope with. Also remember that the aim of
syntax highlighting is to make programming less prone to error,
\fInot\fP to make code look pretty.
.PP
.SH COLORS
The default colors may be changed by appending to the
\fBMC_COLOR_TABLE\fP environment variable. Foreground and
background colors pairs may be specified for example with:
.PP
.nf
MC_COLOR_TABLE="$MC_COLOR_TABLE:\\
editnormal=lightgray,black:\\
editbold=yellow,black:\\
editmarked=black,cyan"
.fi
.PP
.SH OPTIONS
Most options can now be set from the editors options dialog
box. See the \fBOptions\fP menu. The following options are defined in 
\fB~/.mc/ini\fP and have obvious counterparts in the dialog box.
You can modify them to change the editor behavior, by editing the file. 
Unless specified, a 1 sets the option to on, and a 0 sets it to
off, as is usual.
.TP
.I use_internal_edit
This option is ignored when invoking 
.B mcedit.
.TP
.I editor_key_emulation
1 for 
.B Emacs 
keys, and 0 for normal 
.B Cooledit 
keys.
.TP
.I editor_tab_spacing
Interpret the tab character as being of this length.
Default is 8. You should avoid using
other than 8 since most other editors and text viewers
assume a tab spacing of 8. Use 
.B editor_fake_half_tabs 
to simulate a smaller tab spacing.
.TP
.I editor_fill_tabs_with_spaces
Never insert a tab space. Rather insert spaces (ascii 20h) to fill to the
desired tab size.
.TP
.I editor_return_does_auto_indent
Pressing return will tab across to match the indentation
of the first line above that has text on it.
.TP
.I editor_backspace_through_tabs
Make a single backspace delete all the space to the left
margin if there is no text between the cursor and the left
margin.
.TP
.I editor_fake_half_tabs
This will emulate a half tab for those who want to program
with a tab spacing of 4, but do not want the tab size changed
from 8 (so that the code will be formatted the same when displayed
by other programs). When editing between text and the left 
margin, moving and tabbing will be as though a tab space were
4, while actually using spaces and normal tabs for an optimal fill.
When editing anywhere else, a normal tab is inserted.
.TP
.I editor_option_save_mode
(0, 1 or 2.) The save mode (see the options menu also)
allows you to change the method
of saving a file. Quick save (0) saves the file by immediately,
truncating the disk file to zero length (i.e. erasing it)
and the writing the editor contents to the file. This method
is fast, but dangerous, since a system error during a file
save will leave the file only partially written, possibly
rendering the data irretrievable. When saving, the safe save (1)
option enables creation of a temporary file into which the
file contents are first written. In the event of an problem,
the original file is untouched. When the temporary file is
successfully written, it is renamed to the name of the original
file, thus replacing it. The safest method is create
backups (2). Where a backup file is created before any changes
are made. You can specify your own backup file extension in
the dialog. Note that saving twice will replace your backup
as well as your original file.
.PP
.SH Miscellaneous

(Scanf search and replace have previously not worked properly.
With this release, problems with search and replace have been
fixed.)

You can use scanf search and replace to search and replace
a C format string. First take a look at the 
.B sscanf 
and 
.B sprintf 
man pages to see what a format string
is and how it works. An example is as follows: Suppose you want
to replace all occurrences of say, an open bracket, three
comma separated numbers, and a close bracket, with the
word 
.I apples, 
the third number, the word 
.I oranges
and then the second number, you would fill in the Replace dialog
box as follows:

.nf
.B Enter search string
(%d,%d,%d)
.B Enter replace string
apples %d oranges %d
.B Enter replacement argument order
3,2
.fi

The last line specifies that the third and then the second
number are to be used in place of the first and second.

It is advisable to use this feature with Prompt On Replace on, because
a match is thought to be found whenever the number of arguments found
matches the number given, which is not always a real match. Scanf also
treats whitespace as being elastic.  Note that the scanf format %[ is
very useful for scanning strings, and whitespace.

The editor also displays non-us characters (160+). When editing
binary files, you should set 
.B display bits 
to 7 bits in the Midnight Commander options menu to keep the
spacing clean.

.PP
.SH FILES
@prefix@/share/mc.hlp
.IP
The help file for the program.
.PP
@prefix@/share/mc/mc.ini
.IP
The default system-wide setup for the Midnight Commander, used only if
the user lacks his own ~/.mc/ini file.
.PP
@prefix@/share/mc/mc.lib
.IP
Global settings for the Midnight Commander.  Settings in this file are
global to any Midnight Commander, it is useful to define site-global
.\"LINK2
terminal settings.
.\"Terminal databases"
.PP
$HOME/.mc/ini
.IP
User's own setup. If this file is present then the setup is loaded
from here instead of the system-wide startup file.
.PP
$HOME/.mc/cedit/
.IP
User's own temporary directory where block commands are processed
and saved.
.PP
.\"SKIP_SECTION"
.SH LICENSE
This program is distributed under the terms of the GNU General Public
License as published by the Free Software Foundation. See the built-in
help of the Midnight Commander for details on the License and the lack
of warranty.
.SH AVAILABILITY
The latest version of this program can be found at 
ftp://ftp.gnome.org/mirror/gnome.org/stable/sources/mc/ and on the
mirrors listed on the GNOME site http://www.gnome.org/.
.SH SEE ALSO
cooledit(1), mc(1), gpm(1), terminfo(1), scanf(3).
.PP
.SH AUTHORS
Paul Sheer (psheer@obsidian.co.za) is the developer of
the Midnight Commander's internal editor.
.PP
.SH BUGS
Bugs should be reported to mc-devel@gnome.org