xmodmap(1X) xmodmap(1X)
NAME
xmodmap - utility for modifying keymaps in X
SYNOPSIS
xmodmap [options...] [filename]
OPTIONS
The following options may be used with xmodmap: This option specifies the host and display to use. This option indicates that a brief
description of the command line arguments should be printed on the standard error channel. This will be done whenever an unhandled argu-
ment is given to xmodmap. This option indicates that a help message describing the expression grammar used in files and with -e expres-
sions should be printed on the standard error. This option indicates that xmodmap should print logging information as it parses its input.
This option turns off the verbose logging. This is the default. This option indicates that xmodmap should not change the mappings, but
should display what it would do, like make(1) does when given this option. This option specifies an expression to be executed. Any number
of expressions may be specified from the command line. This option indicates that the current modifier map should be printed on the stan-
dard output. This option indicates that the current modifier map should be printed on the standard output in the form of expressions that
can be fed back to xmodmap. This option indicates that the current keymap table should be printed on the standard output. This option
indicates that the current keymap table should be printed on the standard output in the form of expressions that can be fed back to
xmodmap. This option indicates that the current pointer map should be printed on the standard output. A lone dash means that the standard
input should be used as the input file.
The filename specifies a file containing xmodmap expressions to be executed. This file is usually kept in the user's home directory with a
name like
DESCRIPTION
The xmodmap program is used to edit and display the keyboard modifier map and keymap table that are used by client applications to convert
event keycodes into keysyms. It is usually run from the user's session startup script to configure the keyboard according to personal
tastes.
EXPRESSION GRAMMAR
The xmodmap program reads a list of expressions and parses them all before attempting to execute any of them. This makes it possible to
refer to keysyms that are being redefined in a natural way without having to worry as much about name conflicts. The list of keysyms is
assigned to the indicated keycode (which may be specified in decimal, hex or octal and can be determined by running the xev program. If no
existing key has the specified list of keysyms assigned to it, a spare key on the keyboard is selected and the keysyms are assigned to it.
The list of keysyms may be specified in decimal, hex or octal. The KEYSYMNAME on the left hand side is translated into matching keycodes
used to perform the corresponding set of keycode expressions. The list of keysym names may be found in the header file <X11/keysymdef.h>
(without the XK_ prefix) or the keysym database <XRoot>/lib/X11/XKeysymDB, where <XRoot> refers to the root of the X11 install tree. Note
that if the same keysym is bound to multiple keys, the expression is executed for each matching keycode. This removes all entries in the
modifier map for the given modifier, where valid name are: Shift, Lock, Control, Mod1, Mod2, Mod3, Mod4, and Mod5 (case does not matter in
modifier names, although it does matter for all other names). For example, "clear Lock" will remove all any keys that were bound to the
shift lock modifier. This adds all keys containing the given keysyms to the indicated modifier map. The keysym names are evaluated after
all input expressions are read to make it easy to write expressions to swap keys (see the EXAMPLES section). This removes all keys con-
taining the given keysyms from the indicated modifier map. Unlike add, the keysym names are evaluated as the line is read in. This allows
you to remove keys from a modifier without having to worry about whether or not they have been reassigned. This sets the pointer map back
to its default settings (button 1 generates a code of 1, button 2 generates a 2, and so forth.). This sets to pointer map to contain the
indicated button codes. The list always starts with the first physical button.
Lines that begin with an exclamation point (!) are taken as comments.
If you want to change the binding of a modifier key, you must also remove it from the appropriate modifier map.
EXAMPLES
Many pointers are designed such that the first button is pressed using the index finger of the right hand. People who are left-handed fre-
quently find that it is more comfortable to reverse the button codes that get generated so that the primary button is pressed using the
index finger of the left hand. This could be done on a 3 button pointer as follows:
% xmodmap -e "pointer = 3 2 1"
Many applications support the notion of Meta keys (similar to Control keys except that Meta is held down instead of Control). However,
some servers do not have a Meta keysym in the default keymap table, so one needs to be added by hand. The following command will attach
Meta to the Multi-language key (sometimes labeled Compose Character). It also takes advantage of the fact that applications that need a
Meta key simply need to get the keycode and do not require the keysym to be in the first column of the keymap table. This means that
applications that are looking for a Multi_key (including the default modifier map) will not notice any change.
% xmodmap -e "keysym Multi_key = Multi_key Meta_L"
Similarly, some keyboards have an Alt key but no Meta key. In that case the following may be useful:
% xmodmap -e "keysym Alt_L = Meta_L Alt_L"
One of the more simple, yet convenient, uses of xmodmap is to set the keyboard's "rubout" key to generate an alternate keysym. This fre-
quently involves exchanging Backspace with Delete to be more comfortable to the user. If the ttyModes resource in xterm is set as well, all
terminal emulator windows will use the same key for erasing characters:
% xmodmap -e "keysym BackSpace = Delete" % echo "XTerm*ttyModes: erase ^?" | xrdb -merge
Some keyboards do not automatically generate less than and greater than characters when the comma and period keys are shifted. This can be
remedied with xmodmap by resetting the bindings for the comma and period with the following scripts:
! ! make shift-, be < and shift-. be > ! keysym comma = comma less keysym period = period greater
One of the more irritating differences between keyboards is the location of the Control and Shift Lock keys. A common use of xmodmap is to
swap these two keys as follows:
! ! Swap Caps_Lock and Control_L ! remove Lock = Caps_Lock remove Control = Control_L keysym Control_L = Caps_Lock keysym Caps_Lock =
Control_L add Lock = Caps_Lock add Control = Control_L
The keycode command is useful for assigning the same keysym to multiple keycodes. Although unportable, it also makes it possible to write
scripts that can reset the keyboard to a known state. The following script sets the backspace key to generate Delete (as shown above),
flushes all existing caps lock bindings, makes the CapsLock key be a control key, make F5 generate Escape, and makes Break/Reset be a shift
lock.
! ! On the HP, the following keycodes have key caps as listed: ! ! 101 Backspace ! 55 Caps ! 14 Ctrl ! 15
Break/Reset ! 86 Stop ! 89 F5 ! keycode 101 = Delete keycode 55 = Control_R clear Lock add Control = Control_R keycode 89 =
Escape keycode 15 = Caps_Lock add Lock = Caps_Lock
ENVIRONMENT
to get default host and display number.
BUGS
Every time a keycode expression is evaluated, the server generates a MappingNotify event on every client. This can cause some thrashing.
All of the changes should be batched together and done at once. Clients that receive keyboard input and ignore MappingNotify events will
not notice any changes made to keyboard mappings.
xmodmap should generate "add" and "remove" expressions automatically whenever a keycode that is already bound to a modifier is changed.
There should be a way to have the remove expression accept keycodes as well as keysyms for those times when you really mess up your map-
pings.
SEE ALSO
X(1X), xev(1X), Xlib documentation on key and pointer events
AUTHOR
Jim Fulton, MIT X Consortium, rewritten from an earlier version by David Rosenthal of Sun Microsystems.
xmodmap(1X)