xmodmap - utility for modifying keymaps in X


xmodmap [-options ...] [filename]


The xmodmap(1) 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.


The following options can be used with xmodmap(1):

-display display
Use the specified host and display.
-e expression
This option specifies an expression to be executed. Any number of expressions can be specified from the command line.
Print on the standard error a help message describing the expression grammar used in files and with expressions.
Print on the standard error a brief description of the command-line arguments. This description is printed whenever you give xmodmap(1) an unhandled argument.
Do not change the mappings but display what would happen, like make(1) does when given this option.
Turn off the verbose logging. This is the default.
Print the current modifier map on the standard output.
Print the current keymap table on the standard output.
Print on standard output the current keymap table, in the form of expressions that can be fed back to xmodmap(1).
Print on the standard output the current pointer map.
Print logging information as it parses its input.
A single dash means that the standard input should be used as the input file.

The filename specifies a file containing xmodmap(1) expressions to be executed. This file is usually kept in the user's home directory with a name like .xmodmaprc.


The xmodmap(1) 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 can be specified in decimal, hex, or octal, and can be determined by running the xev(1) program in the examples directory).
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 can be found in the header file X11/keysymdef.h (without the XK_ prefix) or the keysym database /usr/lib/X11/XKeysymDB. 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; however, 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.
pointer = default
This sets the pointer map back to its default settings (button 1 generates a code of 1, button 2 generates a 2, and so on).
pointer = NUMBER...
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.


Many pointers are designed so 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 three-button pointer as follows:

$  xmodmap -e "pointer = 3 2 1"

Many editor applications support the notion of Meta keys (similar to Control keys except that Meta is held down instead of Control). Some servers do not have a Meta keysym in the default keymap table, however, so one must be added manually. 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"

One of the simpler, more convenient uses of xmodmap(1) 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(1) 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(1) 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(1) 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 it is not portable, it does make 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 a control key, makes F5 generate Escape, and makes Break/Reset into 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


Contains default host and display number.


Each 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.

The xmodmap(1) utility 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.




Xlib documentation on key and pointer events