MG(1)

NAME

mg -- emacs-like text editor

SYNOPSIS

mg [-n] [-f mode] [+number] [file ...]

DESCRIPTION

mg is intended to be a small, fast, and portable editor for people who can't (or don't want to) run emacs for one reason or another, or are not familiar with the vi(1) editor. It is compatible with emacs because
there shouldn't be any reason to learn more editor types than emacs or
vi(1).

The options are as follows:

+number: Go to the line specified by number (do not insert a space between the '+' sign and the number). If a negative number is specified, the line number counts backwards from the end of the file i.e.
+-1 will be the last line of the file, +-2 will be second last,
and so on.
-f mode: Run the mode command for all buffers created from arguments on
the command line, including the scratch buffer and all files.
-n Turn off backup file generation.

WINDOWS AND BUFFERS

When a file is loaded into mg, it is stored in a buffer. This buffer may be displayed on the screen in more than one window. At present, windows may only be split horizontally, so each window is delineated by a modeline at the bottom. If changes are made to a buffer, it will be
reflected in all open windows.

POINT AND MARK

The current cursor location in mg is called the point (or dot). It is possible to define a window-specific region of text by setting a second
location, called the mark. The region is the text between point and mark inclusive. Deleting the character at the mark position leaves the mark
at the point of deletion.

Note: The point and mark are window-specific in mg, not buffer-specific, as in other emacs flavours.

DEFAULT KEY BINDINGS

Normal editing commands are very similar to Gnu Emacs. In the following examples, C-x means control-X, and M-x means Meta-X, where the Meta key
may be either a special key on your keyboard or the ALT key; otherwise
ESC followed by the key X works as well.

C-SPC set-mark-command
C-a beginning-of-line
C-b backward-char
C-d delete-char
C-e end-of-line
C-f forward-char
C-g keyboard-quit
C-h C-h help-help
C-h a apropos
C-h b describe-bindings
C-h c describe-key-briefly
C-j newline-and-indent
C-k kill-line
C-l recenter
RET newline
C-n next-line
C-o open-line
C-p previous-line
C-q quoted-insert
C-r isearch-backward
C-s isearch-forward
C-t transpose-chars
C-u universal-argument
C-v scroll-up
C-w kill-region
C-x C-b list-buffers
C-x C-c save-buffers-kill-emacs
C-x C-f find-file
C-x C-g keyboard-quit
C-x C-l downcase-region
C-x C-o delete-blank-lines
C-x C-q toggle-read-only
C-x C-r find-file-read-only
C-x C-s save-buffer
C-x C-u upcase-region
C-x C-v find-alternate-file
C-x C-w write-file
C-x C-x exchange-point-and-mark
C-x ( start-kbd-macro
C-x) end-kbd-macro
C-x 0 delete-window
C-x 1 delete-other-windows
C-x 2 split-window-vertically
C-x 4 C-f find-file-other-window
C-x 4 C-g keyboard-quit
C-x 4 b switch-to-buffer-other-window
C-x 4 f find-file-other-window
C-x = what-cursor-position
C-x ^ enlarge-window
C-x ` next-error
C-x b switch-to-buffer
C-x d dired
C-x e call-last-kbd-macro
C-x f set-fill-column
C-x g goto-line
C-x i insert-file
C-x k kill-buffer
C-x n other-window
C-x o other-window
C-x p previous-window
C-x s save-some-buffers
C-x u undo
C-y yank
C-z suspend-emacs
M-C-v scroll-other-window
M-SPC just-one-space
M-% query-replace
M-< beginning-of-buffer
M-> end-of-buffer
M-\ delete-horizontal-space
M-b backward-word
M-c capitalize-word
M-d kill-word
M-f forward-word
M-l downcase-word
M-q fill-paragraph
M-r search-backward
M-s search-forward
M-u upcase-word
M-v scroll-down
M-w copy-region-as-kill
M-x execute-extended-command
M-{ backward-paragraph
M-} forward-paragraph
M-~ not-modified
M-DEL backward-kill-word
C-_ undo
) blink-and-insert
DEL delete-backward-char

For a complete description of mg commands, see MG COMMANDS. To see the active keybindings at any time, type ``M-x describe-bindings''.

MG COMMANDS

Commands are invoked by ``M-x'', or by binding to a key. Many commands
take an optional numerical parameter, n. This parameter is set either by M-<n> (where n is the numerical argument) before the command, or by one or more invocations of the universal argument, usually bound to C-U.
When invoked in this manner, the value of the numeric parameter to be
passed is displayed in the minibuffer before the M-x. One common use of the parameter is in mode toggles (e.g. make-backup-files). If no parameter is supplied, the mode is toggled to its alternate state. If a positive parameter is supplied, the mode is forced to on. Otherwise, it is
forced to off.

apropos: Help Apropos. Prompt the user for a string, open the *help* buffer, and list all mg commands that contain that string.
auto-execute: Register an auto-execute hook; that is, specify a filename pattern (conforming to the shell's filename globbing rules) and an associated function to execute when a file matching the specified pattern is read into a buffer.
auto-fill-mode: Toggle auto-fill mode (sometimes called mail-mode), where text
inserted past the fill column is automatically wrapped to a new
line.
auto-indent-mode: Toggle indent mode, where indentation is preserved after a newline.
backward-char: Move cursor backwards one character.
backward-kill-word: Kill text backwards by n words.
backward-paragraph: Move cursor backwards n paragraphs. Paragraphs are delimited by <NL><NL> or <NL><TAB> or <NL><SPACE>.
backward-word: Move cursor backwards by the specified number of words.
beginning-of-buffer: Move cursor to the top of the buffer.
beginning-of-line: Move cursor to the beginning of the line.
blink-and-insert: Self-insert a character, then search backwards and blink its
matching delimeter. For delimeters other than parenthesis, brackets, and braces, the character itself is used as its own match.
bsmap-mode: Toggle bsmap mode, where DEL and c-H are swapped.
c-mode: Toggle a KNF-compliant mode for editing C program files.
call-last-kbd-macro: Invoke the keyboard macro.
capitalize-word: Capitalize n words; i.e. convert the first character of the word to upper case, and subsequent letters to lower case.
cd Change the global working directory. See also global-wd-mode.
copy-region-as-kill: Copy all of the characters in the region to the kill buffer,
clearing the mark afterwards. This is a bit like a kill-region
followed by a yank.
count-matches: Count the number of lines matching the supplied regular expression.
count-non-matches: Count the number of lines not matching the supplied regular
expression.
define-key: Prompts the user for a named keymap (mode), a key, and an mg command, then creates a keybinding in the appropriate map.
delete-backward-char: Delete backwards n characters. Like delete-char, this actually does a kill if presented with an argument.
delete-blank-lines: Delete blank lines around dot. If dot is sitting on a blank line, this command deletes all the blank lines above and below the current line. Otherwise, it deletes all of the blank lines after the current line.
delete-char: Delete n characters forward. If any argument is present, it kills rather than deletes, saving the result in the kill buffer.
delete-horizontal-space: Delete any whitespace around the dot.
delete-leading-space: Delete leading whitespace on the current line.
delete-trailing-space: Delete trailing whitespace on the current line.
delete-matching-lines: Delete all lines after dot that contain a string matching the supplied regular expression.
delete-non-matching-lines: Delete all lines after dot that contain a string matching the supplied regular expression.
delete-other-windows: Make the current window the only window visible on the screen.
delete-window: Delete current window.
describe-bindings: List all global and local keybindings, putting the result in the
*help* buffer.
describe-key-briefly: Read a key from the keyboard, and look it up in the keymap. Display the name of the function currently bound to the key.
digit-argument: Process a numerical argument for keyboard-invoked functions.
downcase-region: Set all characters in the region to lower case.
downcase-word: Set characters to lower case, starting at the dot, and ending n words away.
emacs-version: Return an mg version string.
end-kbd-macro: Stop defining a keyboard macro.
end-of-buffer: Move cursor to the end of the buffer.
end-of-line: Move cursor to the end of the line.
enlarge-window: Enlarge the current window by shrinking either the window above or below it.
eval-current-buffer: Evaluate the current buffer as a series of mg commands. Useful for testing mg startup files.
eval-expression: Get one line from the user, and run it. Useful for testing
expressions in mg startup files.
exchange-point-and-mark: Swap the values of "dot" and "mark" in the current window. Return an error if no mark is set.
execute-extended-command: Invoke an extended command; i.e. M-x. Call the message line routine to read in the command name and apply autocompletion to it.
When it comes back, look the name up in the symbol table and run
the command if it is found, passing arguments as necessary. Print an error if there is anything wrong.
fill-paragraph: Justify a paragraph, wrapping text at the current fill column.
find-file: Select a file for editing. First check if you can find the file
in another buffer; if you can find it, just switch to the buffer. If you cannot find the file, create a new buffer, read in the file from disk, and switch to the new buffer.
find-file-read-only: Same as find-file, except the new buffer is set to read-only.
find-alternate-file: Replace the current file with an alternate one. Semantics for
finding the replacement file are the same as find-file, except the current buffer is killed before the switch. If the kill fails, or is aborted, revert to the original file.
find-file-other-window: Opens the specified file in a second buffer. Splits the current
window if necessary.
forward-char: Move cursor forwards (or backwards, if n is negative) n characters. Returns an error if the end of buffer is reached.
forward-paragraph: Move forward n paragraphs. Paragraphs are delimited by <NL><NL> or <NL><TAB> or <NL><SPACE>.
forward-word: Move the cursor forward by the specified number of words.
global-set-key: Bind a key in the global (fundamental) key map.
global-unset-key: Unbind a key from the global (fundamental) key map; i.e. set it to 'rescan'.
global-wd-mode: Toggle global working-directory mode. When enabled, mg defaults to opening files (and executing commands like compile and grep)
relative to the global working directory. When disabled, a working directory is set for each buffer.
goto-line: Go to a specific line. If an argument is present, then it is the line number, else prompt for a line number to use.
help-help: Prompts for one of (a)propos, (b)indings, des(c)ribe key briefly.
insert: Insert a string, mainly for use from macros.
insert-buffer: Insert the contents of another buffer at dot.
insert-file: Insert a file into the current buffer at dot.
insert-with-wrap: Insert the bound character with word wrap. Check to see if we're past the fill column, and if so, justify this line.
isearch-backward: Use incremental searching, initially in the reverse direction.
isearch ignores any explicit arguments. If invoked during macro
definition or evaluation, the non-incremental search-backward is
invoked instead.
isearch-forward: Use incremental searching, initially in the forward direction.
isearch ignores any explicit arguments. If invoked during macro
definition or evaluation, the non-incremental search-forward is
invoked instead.
just-one-space: Delete any whitespace around dot, then insert a space.
keyboard-quit: Abort the current action.
kill-buffer: Dispose of a buffer, by name. Prompt the user if the buffer has
been changed.
kill-line: Kill line. If called without an argument, it kills from dot to
the end of the line, unless it is at the end of the line, when it kills the newline. If called with an argument of 0, it kills from the start of the line to dot. If called with a positive argument, it kills from dot forward over that number of newlines. If called with a negative argument it kills any text before dot on the current line, then it kills back abs(n) lines.
kill-paragraph: Delete n paragraphs starting with the current one.
kill-region: Kill the currently defined region.
kill-word: Delete forward n words.
line-number-mode: Toggle whether line and column numbers are displayed in the modeline.
list-buffers: Display the list of available buffers.
load Prompt the user for a filename, and then execute commands from: that file.
local-set-key: Bind a key mapping in the local (topmost) mode.
local-unset-key: Unbind a key mapping in the local (topmost) mode.
make-backup-files: Toggle generation of backup files.
meta-key-mode: When disabled, the meta key can be used to insert extended-ascii
(8-bit) characters. When enabled, the meta key acts as usual.
negative-argument: Process a negative argument for keyboard-invoked functions.
newline: Insert a newline into the current buffer.
newline-and-indent: Insert a newline, then enough tabs and spaces to duplicate the
indentation of the previous line. Assumes tabs are every eight
characters.
next-line: Move forward n lines.
no-tab-mode: Toggle notab mode. In this mode, spaces are inserted rather than tabs.
not-modified: Turn off the modified flag in the current buffer.
open-line: Open up some blank space. Essentially, insert n newlines, then back up over them.
other-window: The command to make the next (down the screen) window the current window. There are no real errors, although the command does nothing if there is only 1 window on the screen.
overwrite-mode: Toggle overwrite mode, where typing in a buffer overwrites existing characters rather than inserting them.
prefix-region: Inserts a prefix string before each line of a region. The prefix string is settable by using 'set-prefix-string'.
previous-line: Move backwards n lines.
previous-window: This command makes the previous (up the screen) window the current window. There are no errors, although the command does not do a
lot if there is only 1 window.
push-shell: Suspend mg and switch to alternate screen, if available.
pwd Display current (global) working directory in the status area.
query-replace: Query Replace. Search and replace strings selectively, prompting after each match.
replace-string: Replace string globally without individual prompting.
query-replace-regexp: Replace strings selectively. Does a search and replace operation using regular expressions for both patterns.
quoted-insert: Insert the next character verbatim into the current buffer; i.e.
ignore any function bound to that key.
re-search-again: Perform a regular expression search again, using the same search
string and direction as the last search command.
re-search-backward: Search backwards using a regular expression. Get a search string from the user, and search, starting at dot and proceeding toward
the front of the buffer. If found, dot is left pointing at the
first character of the pattern [the last character that was
matched].
re-search-forward: Search forward using a regular expression. Get a search string
from the user and search for it starting at dot. If found, move
dot to just after the matched characters. display does all the
hard stuff. If not found, it just prints a message.
recenter: Reposition dot in the current window. By default, the dot is centered. If given a positive argument (n), the display is repositioned to line n. If n is negative, it is that line from the bottom.
redraw-display: Refresh the display. Recomputes all window sizes in case something has changed.
save-buffer: Save the contents of the current buffer if it has been changed,
optionally creating a backup copy.
save-buffers-kill-emacs: Offer to save modified buffers and quit mg.
save-some-buffers: Look through the list of buffers, offering to save any buffer that has been changed. Buffers that are not associated with files
(such as *scratch*, *grep*, *compile*) are ignored.
scroll-down: Scroll backwards n pages. A two-line overlap between pages is
assumed. If given a repeat argument, scrolls back lines, not
pages.
scroll-one-line-down: Scroll the display down n lines without changing the cursor position.
scroll-one-line-up: Scroll the display n lines up without moving the cursor position.
scroll-other-window: Scroll the next window in the window list window forward n pages.
scroll-up: Scroll forward one page. A two-line overlap between pages is
assumed. If given a repeat argument, scrolls back lines, not
pages.
search-again: Search again, using the same search string and direction as the
last search command.
search-backward: Reverse search. Get a search string from the user, and search,
starting at dot and proceeding toward the front of the buffer. If found, dot is left pointing at the first character of the pattern (the last character that was matched).
search-forward: Search forward. Get a search string from the user, and search for it starting at dot. If found, dot gets moved to just after the
matched characters, if not found, print a message.
self-insert-command: Insert a character.
set-case-fold-search: Set case-fold searching, causing case nopt to matter in regular
expression searches. This is the default.
set-default-mode: Append the supplied mode to the list of default modes used by subsequent buffer creation. Built in modes include: fill, indent,
overwrite, and notab.
set-fill-column: Prompt the user for a fill column. Used by auto-fill-mode.
set-mark-command: Sets the mark in the current window to the current dot location.
set-prefix-string: Sets the prefix string to be used by the 'prefix-region' command.
shrink-window: Shrink current window by one line. The window immediately below
is expanded to pick up the slack. If only one window is present, this command has no effect.
space-to-tabstop: Insert enough spaces to reach the next tab-stop position. By
default, tab-stops occur every 8 characters.
split-window-vertically: Split the current window. A window smaller than 3 lines cannot be split.
start-kbd-macro: Start defining a keyboard macro. Macro definition is ended by
invoking end-kbd-macro.
suspend-emacs: Suspend mg and switch back to alternate screen, if in use.
switch-to-buffer: Prompt and switch to a new buffer in the current window.
switch-to-buffer-other-window: Switch to buffer in another window.
toggle-read-only: Toggle the read-only flag on the current buffer.
transpose-chars: Transpose the two characters on either side of dot. If dot is at the end of the line, transpose the two characters before it.
Return with an error if dot is at the beginning of line; it seems to be a bit pointless to make this work.
undo Undo the most recent action. If invoked again without an inter: vening command, move the undo pointer to the previous action and
undo it.
undo-boundary: Add an undo boundary. This is not usually done interactively.
undo-boundary-toggle: Toggle whether undo boundaries are generated. Undo boundaries are often disabled before operations that should be considered atomically undoable.
undo-enable: Toggle whether undo information is kept.
undo-list: Show the undo records for the current buffer in a new buffer.
universal-argument: Repeat the next command 4 times. Usually bound to C-u. This command may be stacked; e.g. C-u C-u C-f moves the cursor forward 16 characters.
upcase-region: Upper case region. Change all of the lower case characters in the region to upper case.
upcase-word: Move the cursor forward by the specified number of words. As you move, convert any characters to upper case.
what-cursor-position: Display a bunch of useful information about the current location
of dot. The character under the cursor (in octal), the current
line, row, and column, and approximate position of the cursor in
the file (as a percentage) is displayed. The column position
assumes an infinite position display; it does not truncate just
because the screen does.
write-file: Ask for a file name and write the contents of the current buffer
to that file. Update the remembered file name and clear the buffer changed flag.
yank Yank text from kill-buffer. Unlike emacs, the mg kill buffer con: sists only of the most recent kill. It is not a ring.

CONFIGURATION FILES

There are two configuration files, .mg, and .mg-TERM. Here, TERM represents the name of your terminal type; e.g., if your terminal type is set to ``vt100'', mg will use .mg-vt100 as a startup file. The terminal type startup file is used first.

The startup file format is a list of commands, one per line, as used for interactive evaluation. Strings that are normally entered by the user at any subsequent prompts may be specified after the command name; e.g.:: global-set-key ")" self-insert-command
global-set-key "\^x\^f" find-file
global-set-key "\e[Z" backward-char
set-default-mode fill
set-fill-column 72
auto-execute *.c c-mode

FILES

~/.mg normal startup file
~/.mg-TERM terminal-specific startup file

CAVEATS

Since it is written completely in C, there is currently no language in
which you can write extensions; however, you can rebind keys and change
certain parameters in startup files.

In order to use 8-bit characters (such as German umlauts), the Meta key
needs to be disabled via the ``meta-key-mode'' command.

docs.sk

comprehensive documentation repository

See also