xmodmap - utility for modifying keymaps in X
xmodmap [options...] [filename]
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 argument is given
to xmodmap. This option indicates that a help message
describing the expression grammar used in files and with
-e expressions 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 standard
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
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
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 containing 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
Lines that begin with an exclamation point (!) are taken
If you want to change the binding of a modifier key, you
must also remove it from the appropriate modifier map.
Many pointers are designed such that the first button is
pressed using the index finger of the right hand. People
who are left-handed frequently 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 Multilanguage
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 frequently 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
% 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
! ! 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
to get default host and display number.
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 mappings.
X(1X), xev(1X), Xlib documentation on key and pointer
Jim Fulton, MIT X Consortium, rewritten from an earlier
version by David Rosenthal of Sun Microsystems.
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