xmodmap is a utility for modifying keymaps and pointer button mappings in Xorg.
xmodmap is not directly related to X keyboard extension (XKB), as it uses different (pre-XKB) ideas on how keycodes are processed within X. Generally, it is only recommended for the simplest tasks. See X keyboard extension for advanced layout configuration.
- xmodmap settings are reset by setxkbmap, which not only alters the alphanumeric keys to the values given in the map, but also resets all other keys to the startup default (see LQWiki:Configuring keyboards).
- Due to a limitation of Xorg, xmodmap settings are not applied to hotplugged devices automatically. If a keyboard is added to a system after a custom table has been applied, the custom table will have to be applied again. 
There are two types of keyboard values in Xorg: keycodes and keysyms.
- The keycode is the numeric representation received by the kernel when a key or a mouse button is pressed.
- The keysym is the value assigned to the keycode. For example, pressing
keycode 38, which is mapped to the
keysym 0×61, which matches
ain the ASCII table.
- The keysyms are managed by Xorg in a table of keycodes defining the keycode-keysym relations, which is called the keymap table. This can be shown by running
xmodmap can be installed through the package.
Optionally, install, which is a graphical front-end to xmodmap.
Print the current keymap table formatted into expressions:
$ xmodmap -pke
[...] keycode 57 = n N [...]
Each keycode is followed by the keysym it is mapped to. The above example indicates that the keycode
57 is mapped to the lowercase
n, while the uppercase
N is mapped to keycode
Each keysym column in the table corresponds to a particular combination of modifier keys:
Not all keysyms have to be set, but to assign only a latter keysym, use the
To see which keycode corresponds to a key, see Keyboard input#Identifying keycodes in Xorg for details on the xev utility which will output relevant keycode/keysym information about a key when you press it.
XF86Mail. These keysyms can be found in
/usr/include/X11/XF86keysym.h. Many multimedia programs are designed to work with these keysyms out-of-the-box, without the need to configure any third-party application.
Note that xmodmap is influenced by xkbd settings, so all eight keysym are available for the US(intl) xkbd layout but not for the default US (it is missing the ralt_switch symbol defined in level3). To have all 8 keysyms available you should configure the (intl) variant of the keyboard. Using US layout as an example,
$ setxkbmap -layout 'us(intl)' before calling xmodmap to test your changes in the current X session. To permanently make this change, edit the xorg configuration or your .xprofile or .xinitrc file. See Xorg/Keyboard configuration#Setting keyboard layout for a full explanation.
To create a key map (i.e.
$ xmodmap -pke > ~/.Xmodmap
To test the changes:
$ xmodmap ~/.Xmodmap
Activating the custom table
[[ -f ~/.Xmodmap ]] && xmodmap ~/.Xmodmap
Alternatively, edit the global startup script
To make temporary changes:
$ xmodmap -e "keycode 46 = l L l L lstroke Lstroke lstroke" $ xmodmap -e "keysym a = e E"
Print the current modifier table verbosely (full sample):
$ xmodmap -pm
xmodmap: up to 4 keys per modifier, (keycodes in parentheses): shift Shift_L (0x32), Shift_R (0x3e) lock Caps_Lock (0x42) control Control_L (0x25), Control_R (0x69) mod1 Alt_L (0x40), Meta_L (0xcd) mod2 Num_Lock (0x94) mod3 mod4 Super_R (0x86), Super_L (0xce), Hyper_L (0xcf) mod5 ISO_Level3_Shift (0x5c), ISO_Level3_Shift (0x6c), Mode_switch (0x85), Mode_switch (0xcb)
Finding the keysym column modifier keys
- The AltGr key on non-US keyboards calls modifier ISO_Level3_Shift. (On US keyboards, the right-alt
Alt_Rhas the same function as the left-alt
Alt_L, which makes setting the layout as US international preferable. See #Keymap table.)
- The Mode_switch modifier may be mapped by default to a key that is not on your keyboard.
Mode_switchis different between xmodmap and X Keyboard Extension. See also .
Reassigning modifiers to keys on your keyboard
Mode_Switchinstead of the correct
Mode_switchwill cause errors.
Before assignment, the modifier keys need to be cleared. This applies to both modifiers you intend to assign and modifiers on keys that you intend to use. For example, if you intend to assign
Caps_Lock to your A key and
B to your NumLock key, you need to first clear the modifiers for both
Num_Lock, then assign the keysyms, and finally add back the modifiers.
[...] clear lock clear mod2 keycode 38 = Caps_Lock keycode 77 = Num_Lock add lock = Caps_Lock add mod2 = Num_Lock
! is a comment, so only the modifiers
Mod4 get cleared in the following example. Then the keysyms
Super_R are assigned to the opposite modifier. Assigning both left and right to the same modifier means that both keys are treated the same way.
[...] !clear Shift !clear Lock clear Control !clear Mod1 !clear Mod2 !clear Mod3 clear Mod4 !clear Mod5 !add Shift = Shift_L Shift_R !add Lock = Caps_Lock add Control = Super_L Super_R !add Mod1 = Alt_L Alt_R !add Mod2 = Mode_switch !add Mod3 = add Mod4 = Control_L Control_R !add Mod5 =
Control_Rkeysyms were assigned to the
Super_Rkeysyms to the
Mod4modifier. If you get the following error message
X Error of failed request: BadValue (integer parameter out of range for operation), you will need to adapt accordingly. Running
xmodmapproduces a list of modifiers and keys that are assigned to them.
The following example modifies
clear lock clear control add control = Caps_Lock Control_L Control_R keycode 66 = Control_L Caps_Lock NoSymbol NoSymbol
A compose key serves to create special characters and symbols that may not be directly accessible on the keyboard. This is especially useful for typing accented letters from non-English languages. For example, pressing
' in succession will produce é. Some characters require more than 2 keys to be pressed after
Usually a modifier key of choice is mapped to
Compose. The compose key can be set in the GUI settings of most desktop environments, but these options will not work if a custom key map table is used as described in this article.
To set the compose key using
Xmodmap, use the
Multi_key identifier. For example, to map the right alt key (
AltGr) to the compose key:
[...] keycode 108 = Multi_key Alt_R Meta_R Alt_R Meta_R
The keycode number could vary based on keyboard models.
The natural scrolling feature available in OS X Lion (mimicking smartphone or tablet scrolling) can be replicated with xmodmap. Since the synaptics driver uses the buttons 4/5/6/7 for up/down/left/right scrolling, you simply need to swap the order of how the buttons are declared in
pointer = 1 2 3 5 4 7 6 8 9 10 11 12
Then update xmodmap:
$ xmodmap ~/.Xmodmap
The left, middle and right mouse buttons correspond to buttons 1,2 and 3 respectively in the synaptics driver. To swap left and right mouse buttons, again simply reverse the order in which they are listed in your
pointer = 3 2 1
This should suffice for a simple mouse setup. Again, update xmodmap:
$ xmodmap ~/.Xmodmap
keycode 24 = a A aacute Aacute ae AE ae keycode 26 = e E eacute Eacute EuroSign cent EuroSign keycode 30 = u U uacute Uacute downarrow uparrow downarrow keycode 31 = i I iacute Iacute rightarrow idotless rightarrow keycode 32 = o O oacute Oacute oslash Oslash oslash keycode 57 = n N ntilde Ntilde n N n keycode 58 = comma question comma questiondown dead_acute dead_doubleacute dead_acute keycode 61 = exclam section exclamdown section dead_belowdot dead_abovedot dead_belowdot !Maps the Mode key to the Alt key keycode 64 = Mode_switch
keycode 54 = c C c C ccircumflex Ccircumflex keycode 42 = g G g G gcircumflex Gcircumflex keycode 43 = h H h H hcircumflex Hcircumflex keycode 44 = j J j J jcircumflex Jcircumflex keycode 39 = s S s S scircumflex Scircumflex keycode 30 = u U u U ubreve Ubreve
Turn CapsLock into Control
Simplest example of changing
clear lock clear control keycode 66 = Control_L add control = Control_L Control_R
Turn CapsLock into Control, and LeftControl into Hyper
clear lock clear control clear mod1 clear mod2 clear mod3 clear mod4 clear mod5 keycode 37 = Hyper_L keycode 66 = Control_L add control = Control_L Control_R add mod1 = Alt_L Alt_R Meta_L add mod2 = Num_Lock add mod3 = Hyper_L add mod4 = Super_L Super_R add mod5 = Mode_switch ISO_Level3_Shift
Turn Super_R into Hyper_R
Users who wish to have a
Hyper key on full keyboard layout may wish to use the Right
Super key as
remove mod4 = Super_R keycode 134 = Hyper_R add mod3 = Hyper_R
Switch every number key N with Shift-N and vice-versa, for Croatian layout
Should work fine for layouts similar to Croatian as well.
keycode 10 = exclam 1 1 exclam asciitilde dead_tilde asciitilde keycode 11 = quotedbl 2 2 quotedbl dead_caron caron dead_caron keycode 12 = numbersign 3 3 numbersign asciicircum dead_circumflex asciicircum keycode 13 = dollar 4 4 dollar dead_breve breve dead_breve keycode 14 = percent 5 5 percent degree dead_abovering degree keycode 15 = ampersand 6 6 ampersand dead_ogonek ogonek dead_ogonek keycode 16 = slash 7 7 slash grave dead_grave grave keycode 17 = parenleft 8 8 parenleft dead_abovedot abovedot dead_abovedot keycode 18 = parenright 9 9 parenright dead_acute apostrophe dead_acute keycode 19 = equal 0 0 equal dead_doubleacute doubleacute dead_doubleacute