.\"	$OpenBSD: mg.1,v 1.36 2008/05/29 19:58:15 sobrado Exp $
.\" This file is in the public domain.
.\"
.Dd $Mdocdate: May 29 2008 $
.Dt MG 1
.Os
.Sh NAME
.Nm mg
.Nd emacs-like text editor
.Sh SYNOPSIS
.Nm mg
.Op Fl n
.Op Fl f Ar mode
.Op + Ns Ar number
.Op Ar
.Sh DESCRIPTION
.Nm
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
.Xr vi 1
editor.
It is compatible with emacs because there shouldn't
be any reason to learn more editor types than emacs or
.Xr vi 1 .
.Pp
The options are as follows:
.Bl -tag -width Ds
.It + Ns Ar number
Go to the line specified by number (do not insert
a space between the
.Sq +
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.
.It Fl f Ar mode
Run the mode command for all buffers created from
arguments on the command line, including the
scratch buffer and all files.
.It Fl n
Turn off backup file generation.
.El
.Sh WINDOWS AND BUFFERS
When a file is loaded into
.Nm ,
it is stored in a
.Em 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.
.Sh POINT AND MARK
The current cursor location in
.Nm
is called the
.Em point .
It is possible to define a window-specific region of text by setting a second
location, called the
.Em mark .
The
.Em region
is the text between point and mark inclusive.
Deleting the character at the mark position leaves
the mark at the point of deletion.
.Pp
Note: The point and mark are window-specific in
.Nm ,
not buffer-specific, as in other emacs flavours.
.Sh DEFAULT KEY BINDINGS
Normal editing commands are very similar to Gnu Emacs.
In the following examples, ^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.
.Pp
.Bl -tag -width xxxxx -compact
.It ^F
Forward character.
.It ^B
Backwards character.
.It ^N
Next line.
.It ^P
Previous line.
.It ^A
Start of line.
.It ^E
End of line.
.It ^D
Delete current character.
.It ^S
Interactive search forward.
.It ^R
Interactive search backwards.
.It M-%
Interactive search-and-replace.
.It ^O
Open a new line at cursor position.
.It ^T
Transpose characters.
.It ^U
Repeat next command 4 times
(can be cascaded i.e. ^U^U^F will move 16 characters forward).
.Pp
.It ^K
Kill to end of line (placing into kill buffer).
.It ^Y
Yank kill buffer into current location.
.It ^SPC
Set mark.
.It ^W
Kill region
(cuts from previously set mark to current location, into kill buffer).
.It M-W
Copy region (into kill buffer).
.Pp
.It ^V
Next page.
.It M-V
Previous page.
.It M-<
Start of buffer.
.It M->
End of buffer.
.Pp
.It ^X^C
Save buffers and quit.
.It ^X-O
Next window.
.It ^X-N
Next window.
.It ^X-P
Previous window.
.It ^X-U
Undo.
.It ^_
Undo.
.El
.Pp
For a complete set of key bindings, type
.Dq M-x describe-bindings .
.Sh COMMANDS
Commands are invoked by
.Dq M-x ,
or by binding to a key.
Many commands take an optional numerical parameter,
.Va n .
This parameter is set either by
M-<n> (where
.Va 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.
.\" A complete list of commands is given in mg(5)
.Sh CONFIGURATION FILES
There are two configuration files,
.Pa .mg ,
and
.Pa .mg-TERM .
Here,
.Ev TERM
represents the name of your terminal type; e.g., if your terminal type
is set to
.Dq vt100 ,
.Nm
will use
.Pa .mg-vt100
as a startup file.
The terminal type startup file is used first.
.Pp
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.:
.Bd -literal -offset indent
auto-fill-mode
set-fill-column 72
global-set-key "\e^x\e^f" find-file
.Ed
.Sh FILES
.Bl -tag -width ~/.mg-TERM -compact
.It Pa ~/.mg
normal startup file
.It Pa ~/.mg-TERM
terminal-specific startup file
.El
.Sh SEE ALSO
.Xr vi 1
.Sh CAVEATS
.Nm
differs from other emacs implementations primarily in not having many
special modes for tasks other than straight editing, and in not having
special modes that support various programming languages.
.Pp
Since it is written completely in C, there is no
language in which you can write extensions;
however, you can rebind keys and change certain parameters.
.Pp
In order to use 8-bit characters (such as German umlauts), the Meta key
needs to be disabled via the
.Dq meta-key-mode
command.