mc/doc/mcedit.1.in

.TH MCEDIT 1 "September 2007" "MC Version 4.6.2-pre1" "GNU Midnight Commander"
.SH NAME
mcedit \- Internal file editor of GNU Midnight Commander.
.SH USAGE
.B mcedit
[\-bcCdfhstVx?] [+lineno] file
.PP
.B mcedit
[\-bcCdfhstVx?] file:lineno[:]
.SH DESCRIPTION
.LP
mcedit is a link to
.BR mc ,
the main GNU Midnight Commander executable.  Executing GNU Midnight
Commander under this name requests staring the internal editor and
opening the
.I file
specified on the command line.  The editor is based on the terminal
version of
.B cooledit
\- standalone editor for X Window System.
.SH OPTIONS
.TP
.I "+lineno"
Go to the line specified by number (do not put a space between the
.I "+"
sign and the number).
.TP
.I "\-b"
Force black and white display.
.TP
.I "\-c"
Force ANSI color mode on terminals that don't seem to have color
support.
.TP
.I "\-C <keyword>=<FGcolor>,<BGcolor>:<keyword>= ..."
Specify a different color set.  See the
.B Colors
section in mc(1) for more information.
.TP
.I "\-d"
Disable mouse support.
.TP
.I "\-f"
Display the compiled-in search path for GNU Midnight Commander data
files.
.TP
.I "\-t"
Force using termcap database instead of terminfo.  This option is only
applicable if GNU Midnight Commander was compiled with S-Lang library
with terminfo support.
.TP
.I "\-V"
Display the version of the program.
.TP
.I "\-x"
Force xterm mode.  Used when running on xterm-capable terminals (two
screen modes, and able to send mouse escape sequences).
.SH FEATURES
The internal file editor is a full-featured full screen editor.  It can
edit files up to 64 megabytes.  It is possible to edit binary files. 
The features it presently supports are: block copy, move, delete, cut,
paste; key for key undo; pull-down menus; file insertion; macro
commands; regular expression search and replace (and our own
scanf-printf search and replace); shift-arrow text highlighting (if
supported by the terminal); insert-overwrite toggle; word wrap;
autoindent; tunable tab size; syntax highlighting for various file
types; and an option to pipe text blocks through shell commands like
indent and ispell.
.SH KEYS
The editor is easy to use and can be used without learning.  The
pull-down menu is invoked by pressing F9.  You can learn other keys from
the menu and from the button bar labels.
.PP
In addition to that, Shift combined with arrows does text highlighting
(if supported by the terminal):
.B Ctrl-Ins
copies to the file
.BR ~/.mc/cedit/cooledit.clip ,
.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.  Mouse highlighting also works on some
terminals.  To use the standard mouse support provided by your terminal,
hold the Shift key.  Please note that the mouse support in the terminal
doesn't share the clipboard with
.BR mcedit .
.PP
The completion key (usually
.B "Alt-Tab"
or
.BR "Escape 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 keys 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.  The macro commands are stored in 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.
.P
.B F19
will format C, C++, Java or HTML 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
.BR ~/.mc/cedit/edit.spell.rc .
.PP
If some keys don't work, you can use
.B Learn Keys
in the
.B Options
menu.
.SH SYNTAX HIGHLIGHTING
.B mcedit
supports 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
.BR ~/.mc/cedit/Syntax .
If this file is missing, system-wide
.B @prefix@/share/mc/syntax/Syntax
is used.
The file
.B ~/.mc/cedit/Syntax
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.
.PP
The file is divided into sections, each beginning with a line with the
.B file
command.  The sections are normally put into separate files using the
.B include
command.
.PP
The
.B file
command has three arguments.  The first argument is a regular expression
that is applied to the file name to determine if the following section
applies to the file.  The second argument is the description of the file
type.  It is used in
.BR cooledit ;
future versions of
.B mcedit
may use it as well.  The third optional argument is a regular expression
to match the first line of text of the file.  The rules in the following
section apply if either the file name or the first line of text matches.
.PP
A section ends with the start of another 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 text within a C style comment (i.e. between
.B /*
and
.BR */ )
has its own color.  This is a context, although it has no further rules
inside it because there is probably nothing that we want highlighted
within a C comment.
.PP
A trivial C programming section might look like this:
.PP
.nf
file .\\*\\\\.c C\\sProgram\\sFile (#include|/\\\\\\*)

wholechars abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_

# default colors
define  comment   brown
context default
  keyword  whole  if       yellow
  keyword  whole  else     yellow
  keyword  whole  for      yellow
  keyword  whole  while    yellow
  keyword  whole  do       yellow
  keyword  whole  switch   yellow
  keyword  whole  case     yellow
  keyword  whole  static   yellow
  keyword  whole  extern   yellow
  keyword         {        brightcyan
  keyword         }        brightcyan
  keyword         '*'      green

# C comments
context /\\* \\*/ comment

# C preprocessor directives
context linestart # \\n red
  keyword  \\\\\\n  brightred

# C string constants
context " " green
  keyword  %d    brightgreen
  keyword  %s    brightgreen
  keyword  %c    brightgreen
  keyword  \\\\"   brightgreen
.fi
.PP
Each context starts with a line of the form:
.PP
.B context
.RB [ exclusive ]
.RB [ whole | wholeright | wholeleft ]
.RB [ linestart ]
.I delim
.RB [ linestart ]
.I delim
.RI [ foreground ]
.RI [ background ]
.PP
The first context is an exception.  It must start with the command
.PP
.B context default
.RI [ foreground ]
.RI [ background ]
.PP
otherwise
.B mcedit
will report an error.  The
.B linestart
option specifies that
.I delim
must start at the beginning of a line.  The
.B whole
option tells that
.I delim
must be a whole word.  To specify that a word must begin on the word
boundary only on the left side, you can use the
.B wholeleft
option, and similarly a word that must end on the word boundary is specified by
.BR wholeright .
.PP
The set of characters that constitute a whole word can be changed at any
point in the file with the
.B wholechars
command.  The left and right set of characters can be set separately
with
.PP
.B wholechars
.RB [ left | right ]
.I characters
.PP
The
.B exclusive
option causes the text between the delimiters to be highlighted, but not
the delimiters themselves.
.PP
Each rule is a line of the form:
.PP
.B keyword
.RB [ whole | wholeright | wholeleft ]
.RB [ linestart ]
.I string foreground
.RI [ background ]
.PP
Context or keyword strings are interpreted, so that you can include tabs
and spaces with the sequences \\t and \\s.  Newlines and backslashes 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
an asterisk.  The * itself is a wildcard that matches any length of
characters.  For example,
.PP
.nf
  keyword         '*'      green
.fi
.PP
colors all C single character constants green.  You also could use
.PP
.nf
  keyword         "*"      green
.fi
.PP
to color string constants, but the matched string would not be allowed
to span across multiple newlines.  The wildcard may be used within
context delimiters as well, but you cannot have a wildcard as the last
or first character.
.PP
Important to note is the line
.PP
.nf
  keyword  \\\\\\n  brightgreen
.fi
.PP
This line defines a keyword containing the backslash and newline
characters.  Since the keywords are matched before the context
delimiters, this keyword prevents the context from ending at the end of
the lines that end in a backslash, thus allowing C preprocessor
directive to continue across multiple lines.
.PP
The possible colors are: black, gray, red, brightred, green,
brightgreen, brown, yellow, blue, brightblue, magenta, brightmagenta,
cyan, brightcyan, lightgray and white.  If the syntax file is shared
with
.BR cooledit ,
it is possible to specify different colors for
.B mcedit
and
.B cooledit
by separating them with a slash, e.g.
.PP
.nf
keyword  #include  red/Orange
.fi
.PP
.B mcedit
uses the color before the slash.  See cooledit(1) for supported
.B cooledit
colors.
.PP
Comments may be put on a separate line starting with the hash sign (#).
.PP
Because of the simplicity of the implementation, there are a few
intricacies that will not be dealt 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 cannot 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.
.PP
A useful hint is to work with as much as possible with the things you
can do rather than try to do things that this implementation cannot deal
with.  Also remember that the aim of syntax highlighting is to make
programming less prone to error, not to make code look pretty.
.SH COLORS
The default colors may be changed by appending to the
.B MC_COLOR_TABLE
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
.SH OPTIONS
Most options can now be set from the editors options dialog box.  See
the
.B Options
menu.  The following options are defined in
.B ~/.mc/ini
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
.BR 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
Possible values 0, 1 and 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.
.SH MISCELLANEOUS
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.  Here's an
example: suppose that you want to replace all occurrences of an open
bracket, three comma separated numbers, and a close bracket, with the
word
.IR apples ,
the third number, the word
.I oranges
and then the second number.  You would fill in the Replace dialog box as
follows:
.PP
.nf
.B Enter search string
(%d,%d,%d)
.B Enter replace string
apples %d oranges %d
.B Enter replacement argument order
3,2
.fi
.PP
The last line specifies that the third and then the second number are to
be used in place of the first and second.
.PP
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.
.PP
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.
.SH FILES
.I @prefix@/share/mc/mc.hlp
.IP
The help file for the program.
.PP
.I @prefix@/share/mc/mc.ini
.IP
The default system-wide setup for GNU Midnight Commander, used only if
the user's own ~/.mc/ini file is missing.
.PP
.I @prefix@/share/mc/mc.lib
.IP
Global settings for the Midnight Commander.  Settings in this file
affect all users, whether they have ~/.mc/ini or not.
.PP
.I @prefix@/share/mc/syntax/*
.IP
The default system-wide syntax files for mcedit, used only if
the corresponding user's own ~/.mc/cedit/ file is missing.
.PP
.I $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 setup file.
.PP
.I $HOME/.mc/cedit/
.IP
User's own directory where block commands are processed and saved and
user's own syntax files are located.
.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.gnu.org/gnu/mc/.
.SH SEE ALSO
cooledit(1), mc(1), gpm(1), terminfo(1), scanf(3).
.SH AUTHORS
Paul Sheer (psheer@obsidian.co.za) is the original author of
the Midnight Commander's internal editor.
.SH BUGS
Bugs should be reported to mc-devel@gnome.org