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You are here: manpages

MCEDIT

Section: GNU Midnight Commander (1)
Updated: September 2016
Index Return to Main Contents

NAME

mcedit - Internal file editor of GNU Midnight Commander.

USAGE

mcedit [-bcCdfhstVx?] [+lineno] [file1] [file2] ...

mcedit [-bcCdfhstVx?] file1:lineno[:] file2:lineno[:] ...

DESCRIPTION

mcedit is a link to mc, the main GNU Midnight Commander executable. Executing GNU Midnight Commander under this name runs the internal editor and opens files specified on the command line. The editor is based on the terminal version of cooledit - standalone editor for X Window System.

OPTIONS

+lineno: Go to the line specified by number (do not put a space between the + sign and the number). Several line numbers are allowed but only the last one will be used, and it will be applied to the first file only.
-b: Force black and white display.
-c: Force ANSI color mode on terminals that don't seem to have color support.
-C <keyword>=<fgcolor>,<bgcolor>,<attributes>:<keyword>= ...: Specify a different color set. See the Colors section in mc(1) for more information.
-d: Disable mouse support.
-f: Display the compiled-in search path for GNU Midnight Commander data files.
-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.
-V: Display the version of the program.
-x: Force xterm mode. Used when running on xterm-capable terminals (two screen modes, and able to send mouse escape sequences).

FEATURES

The internal file editor is a full-featured windowed editor. It can edit several files at the same time. Maximum size of each file is 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; shift-arrow text highlighting (if supported by the terminal); insert-overwrite toggle; autoindent; tunable tab size; syntax highlighting for various file types; and an option to pipe text blocks through shell commands like indent and ispell.

Each file is opened in its own window in full-screen mode. Window control in mcedit is similar to the window control in other multi-window program: double click on window title maximizes the window to full-screen or restores window size and position; left-click on window title and mouse drag moves the window in editor area; left-click on low-right frame corner and mouse drag resizes the window. These actions can be made using "Window" menu.

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.

In addition to that, Shift combined with arrows does text highlighting (if supported by the terminal): Ctrl-Ins copies to the file ~/.cache/mc/mcedit/mcedit.clip, Shift-Ins pastes from ~/.cache/mc/mcedit/mcedit.clip, Shift-Del cuts to ~/.cache/mc/mcedit/mcedit.clip, and 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 mcedit.

The completion key (usually Meta-Tab or Escape Tab) completes the word under the cursor using the words used in the file.

MACRO

To define a macro, press Ctrl-R and then type out the keys you want to be executed. Press Ctrl-R again when finished. The macro can be assigned to any key by pressing that key. The macro is executed when you press the assigned key.

The macro commands are stored in section [editor] it the file ~/.local/share/mc/mc.macros.

External scripts (filters) can be assigned into the any hotkey by edit mc.macros like following:

[editor]
ctrl-W=ExecuteScript:25;

This means that ctrl-W hotkey initiates the ExecuteScript(25) action, then editor handler translates this into execution of ~/.local/share/mc/mcedit/macros.d/macro.25.sh shell script.

External scripts are stored in ~/.local/share/mc/mcedit/macros.d/ directory and must be named as macro.XXXX.sh where XXXX is the number from 0 to 9999. See Edit Menu File for more detail about format of the script.

Following macro definition and directives can be used:

#silent: If this directive is set, then script starts without interactive subshell.
%c: The cursor column position number.
%i: The indent of blank space, equal the cursor column.
%y: The syntax type of current file.
%b: The block file name.
%f: The current file name.
%n: Only the current file name without extension.
%x: The extension of current file name.
%d: The current directory name.
%F: The current file in the unselected panel.
%D: The directory name of the unselected panel.
%t: The currently tagged files.
%T: The tagged files in the unselected panel.
%u and %U: Similar to the %t and %T macros, but in addition the files are untagged. You can use this macro only once per menu file entry or extension file entry, because next time there will be no tagged files.
%s and %S: The selected files: The tagged files if there are any. Otherwise the current file.

Feel free to edit this files, if you need. Here is a sample external script:

l       comment selection
        TMPFILE=`mktemp ${MC_TMPDIR:-/tmp}/up.XXXXXX` || exit 1
        echo #if 0 > $TMPFILE
        cat %b >> $TMPFILE
        echo #endif >> $TMPFILE
        cat $TMPFILE > %b
        rm -f $TMPFILE

If some keys don't work, you can use Learn Keys in the Options menu.

CODE NAVIGATION

mcedit can be used for navigation through code with tags files created by etags or ctags commands. If there is no TAGS file code navigation will not work. For example, in case of exuberant-ctags for C language command will be:

ctags -e --language-force=C -R ./

Meta-Enter shows list box to select item under cursor (cursor should stand at the end of the word).

Meta-Minus where minus is symbol "-" goes to previous function in navigation list (like browser's Back button).

Meta-Equal where equal is symbol "=" goes to next function in navigation list (like browser's Forward button).

SYNTAX HIGHLIGHTING

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 ~/.config/mc/mcedit/Syntax. If this file is missing, system-wide /usr/share/mc/syntax/Syntax is used. The file ~/.config/mc/mcedit/Syntax is rescanned on opening of every 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 with what color.

The file is divided into sections, each beginning with a line with the file command. The sections are normally put into separate files using the include command.

The 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 cooledit; future versions of 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.

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 /* and */) 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.

A trivial C programming section might look like this:

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

Each context starts with a line of the form:

context [exclusive] [whole|wholeright|wholeleft] [linestart] delim [linestart] delim [foreground] [background] [attributes]

The first context is an exception. It must start with the command

context default [foreground] [background] [attributes]

otherwise mcedit will report an error. The linestart option specifies that delim must start at the beginning of a line. The whole option tells that 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 wholeleft option, and similarly a word that must end on the word boundary is specified by wholeright.

The set of characters that constitute a whole word can be changed at any point in the file with the wholechars command. The left and right set of characters can be set separately with

wholechars [left|right] characters

The exclusive option causes the text between the delimiters to be highlighted, but not the delimiters themselves.

Each rule is a line of the form:

keyword [whole|wholeright|wholeleft] [linestart] string foreground [background] [attributes]

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,

  keyword         '*'      green

colors all C single character constants green. You also could use

  keyword         "*"      green

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.

Important to note is the line

  keyword  \\\n  brightgreen

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.

The possible colors are: black, gray, red, brightred, green, brightgreen, brown, yellow, blue, brightblue, magenta, brightmagenta, cyan, brightcyan, lightgray and white. The special keyword "default" means the terminal's default. Another special keyword "base" means mc's main colors, it is useful as a placeholder if you want to specify attributes without modifying the background color. When 256 colors are available, they can be specified either as color16 to color255, or as rgb000 to rgb555 and gray0 to gray23.

If the syntax file is shared with cooledit, it is possible to specify different colors for mcedit and cooledit by separating them with a slash, e.g.

keyword  #include  red/Orange

mcedit uses the color before the slash. See cooledit(1) for supported cooledit colors.

Attributes can be any of bold, italic, underline, reverse and blink, appended by a plus sign if more than one are desired.

Comments may be put on a separate line starting with the hash sign (#).

If you are describing case insensitive language you need to use caseinsensitive directive. It should be specified at the beginning of syntax file.

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.

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.

The syntax highlighting can be toggled using Ctrl-s shortcut.

COLORS

The default colors may be changed by appending to the MC_COLOR_TABLE environment variable. Foreground and background colors pairs may be specified for example with:

MC_COLOR_TABLE="$MC_COLOR_TABLE:\
editnormal=lightgray,black:\
editbold=yellow,black:\
editmarked=black,cyan"

OPTIONS

Most options can be set from Options dialog box. See the Options menu. The following options are defined in ~/.config/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 usual.

use_internal_edit: This option is ignored when invoking mcedit.
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 editor_fake_half_tabs to simulate a smaller tab spacing.
editor_fill_tabs_with_spaces: Never insert a tab character. Rather insert spaces (ascii 32) to fill to the desired tab size.
editor_return_does_auto_indent: Pressing return will tab across to match the indentation of the first line above that has text on it.
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.
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.
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 immediately, truncating the disk file to zero length (i.e. erasing it) and then 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 a 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): 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.
editor_word_wrap_line_length: Line length to wrap at. Default is 72.
editor_backup_extension: Symbol to add to name of backup files. Default is "~".
editor_line_state: Show state line of editor. Currently it shows current line number (in the future it might show things like folding, breakpoints, etc.). M-n toggles this option.
editor_visible_spaces: Toggle "show visible trailing spaces". If editor_visible_spaces=1, they are shown as '.'
editor_visible_tabs: Toggle "show visible tabs". If editor_visible_tabs=1, tabs are shown as '<---->'
editor_persistent_selections: Do not remove block selection after cursor movement.
editor_drop_selection_on_copy: Reset selection after copy to clipboard.
editor_cursor_beyond_eol: Allow moving cursor beyond the end of line.
editor_cursor_after_inserted_block: Allow moving cursor after inserted block.
editor_syntax_highlighting: enable syntax highlighting.
editor_edit_confirm_save: Show confirmation dialog on save.
editor_option_typewriter_wrap: to be described
editor_option_auto_para_formatting: to be described
editor_option_save_position: Save file position on exit.
source_codepage: Symbol representation of codepage name for file (i.e. CP1251, ~ - default).
editor_group_undo: Combine UNDO actions for several of the same type of action (inserting/overwriting, deleting, navigating, typing)
editor_wordcompletion_collect_entire_file: Search autocomplete candidates in entire file (1) or just from beginning of file to cursor position (0).
spell_language: Spelling language (en, en-variant_0, ru, etc) installed with aspell package (a full list can be obtained using 'aspell' utility). Use spell_language = NONE to disable aspell support. Default value is 'en'. Option must be located in the [Misc] section.
editor_stop_format_chars: Set of characters to stop paragraph formatting. If one of those characters is found in the beginning of line, that line and all following lines of paragraph will be untouched. Default value is "-+*\,.;:&>".
editor_state_full_filename: Show full path name in the status line. If disabled (default), only base name of the file is shown.

MISCELLANEOUS

You can use scanf search and replace to search and replace a C format string. First take a look at the sscanf and 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 apples, the third number, the word oranges and then the second number. You would fill in the Replace dialog box as follows:

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

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 display bits to 7 bits in Midnight Commander's options menu to keep the spacing clean.

FILES

/usr/share/mc/mc.hlp

: The help file for the program.

/usr/share/mc/mc.ini

: The default system-wide setup for GNU Midnight Commander, used only if the user's own ~/.config/mc/ini file is missing.

/usr/share/mc/mc.lib

: Global settings for Midnight Commander. Settings in this file affect all users, whether they have ~/.config/mc/ini or not.

/usr/share/mc/syntax/*

: The default system-wide syntax files for mcedit, used only if the corresponding user's own ~/.local/share/mc/mcedit/ file is missing.

~/.config/mc/ini

: User's own setup. If this file is present then the setup is loaded from here instead of the system-wide setup file.

~/.local/share/mc/mcedit/

: User's own directory where block commands are processed and saved and user's own syntax files are located.

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 Midnight Commander for details on the License and the lack of warranty.