keymaps(5) — Linux manual page


KEYMAPS(5)                 File Formats Manual                KEYMAPS(5)

NAME         top

       keymaps - keyboard table descriptions for loadkeys and dumpkeys

DESCRIPTION         top

       These files are used by loadkeys(1) to modify the translation
       tables used by the kernel keyboard driver and generated by
       dumpkeys(1) from those translation tables.

       The format of these files is vaguely similar to the one accepted
       by xmodmap(1).  The file consists of charset or key or string
       definition lines interspersed with comments.

       Comments are introduced with !  or # characters and continue to
       the end of the line. Anything following one of these characters
       on that line is ignored. Note that comments need not begin from
       column one as with xmodmap(1).

       The syntax of keymap files is line oriented; a complete
       definition must fit on a single logical line. Logical lines can,
       however, be split into multiple physical lines by ending each
       subline with the backslash character (\).

INCLUDE FILES         top

       A keymap can include other keymaps using the syntax

              include "pathname"


       A character set definition line is of the form:

              charset "iso-8859-x"

       It defines how following keysyms are to be interpreted.  For
       example, in iso-8859-1 the symbol mu (or micro) has code 0265,
       while in iso-8859-7 the letter mu has code 0354.


       Each complete key definition line is of the form:

              keycode keynumber = keysym keysym keysym...

       keynumber is the internal identification number of the key,
       roughly equivalent to the scan code of it.  keynumber can be
       given in decimal, octal or hexadecimal notation.  Octal is
       denoted by a leading zero and hexadecimal by the prefix 0x.

       Each of the keysyms represent keyboard actions, of which up to
       256 can be bound to a single key. The actions available include
       outputting character codes or character sequences, switching
       consoles or keymaps, booting the machine etc. (The complete list
       can be obtained from dumpkeys(1) by saying  dumpkeys -l .)

       Each keysym may be prefixed by a '+' (plus sign), in which case
       this keysym is treated as a "letter" and therefore affected by
       the "CapsLock" the same way as by "Shift" (to be correct, the
       CapsLock inverts the Shift state).  The ASCII letters ('a'-'z'
       and 'A'-'Z') are made CapsLock'able by default.  If
       Shift+CapsLock should not produce a lower case symbol, put lines

              keycode 30 = +a  A

       in the map file.

       Which of the actions bound to a given key is taken when it is
       pressed depends on what modifiers are in effect at that moment.
       The keyboard driver supports 9 modifiers. These modifiers are
       labeled (completely arbitrarily) Shift, AltGr, Control, Alt,
       ShiftL, ShiftR, CtrlL, CtrlR and CapsShift.  Each of these
       modifiers has an associated weight of power of two according to
       the following table:


              Shift                  1
              AltGr                  2
              Control                4
              Alt                    8
              ShiftL                16
              ShiftR                32
              CtrlL                 64
              CtrlR                128
              CapsShift            256

       The effective action of a key is found out by adding up the
       weights of all the modifiers in effect. By default, no modifiers
       are in effect, so action number zero, i.e. the one in the first
       column in a key definition line, is taken when the key is pressed
       or released. When e.g. Shift and Alt modifiers are in effect,
       action number nine (from the 10th column) is the effective one.

       Changing the state of what modifiers are in effect can be
       achieved by binding appropriate key actions to desired keys. For
       example, binding the symbol Shift to a key sets the Shift
       modifier in effect when that key is pressed and cancels the
       effect of that modifier when the key is released. Binding
       AltGr_Lock to a key sets AltGr in effect when the key is pressed
       and cancels the effect when the key is pressed again.  (By
       default Shift, AltGr, Control and Alt are bound to the keys that
       bear a similar label; AltGr may denote the right Alt key.)

       Note that you should be very careful when binding the modifier
       keys, otherwise you can end up with an unusable keyboard mapping.
       If you for example define a key to have Control in its first
       column and leave the rest of the columns to be VoidSymbols,
       you're in trouble. This is because pressing the key puts Control
       modifier in effect and the following actions are looked up from
       the fifth column (see the table above). So, when you release the
       key, the action from the fifth column is taken. It has VoidSymbol
       in it, so nothing happens. This means that the Control modifier
       is still in effect, although you have released the key.  Re-
       pressing and releasing the key has no effect. To avoid this, you
       should always define all the columns to have the same modifier
       symbol. There is a handy short-hand notation for this, see below.

       keysyms can be given in decimal, octal, hexadecimal, unicode or
       symbolic notation.  The numeric notations use the same format as
       with keynumber.  Unicode notation is "U+" followed by four
       hexadecimal digits.  The symbolic notation resembles that used by
       xmodmap(1).  Notable differences are the number symbols. The
       numeric symbols '0', ..., '9' of xmodmap(1) are replaced with the
       corresponding words 'zero', 'one', ... 'nine' to avoid confusion
       with the numeric notation.

       It should be noted that using numeric notation for the keysyms is
       highly unportable as the key action numbers may vary from one
       kernel version to another and the use of numeric notations is
       thus strongly discouraged. They are intended to be used only when
       you know there is a supported keyboard action in your kernel for
       which your current version of loadkeys(1) has no symbolic name.

       There is a number of short-hand notations to add readability and
       reduce typing work and the probability of typing-errors.

       First of all, you can give a map specification line, of the form

              keymaps 0-2,4-5,8,12

       to indicate that the lines of the keymap will not specify all 256
       columns, but only the indicated ones. (In the example: only the
       plain, Shift, AltGr, Control, Control+Shift, Alt and Control+Alt
       maps, that is, 7 columns instead of 256.)  When no such line is
       given, the keymaps 0-M will be defined, where M+1 is the maximum
       number of entries found in any definition line.

       Next, you can leave off any trailing VoidSymbol entries from a
       key definition line. VoidSymbol denotes a keyboard action which
       produces no output and has no other effects either. For example,
       to define key number 30 to output 'a' unshifted, 'A' when pressed
       with Shift and do nothing when pressed with AltGr or other
       modifiers, you can write

              keycode  30 = a     A

       instead of the more verbose

              keycode  30 = a     A    VoidSymbol     VoidSymbol \
                        VoidSymbol VoidSymbol VoidSymbol ...

       For added convenience, you can usually get off with still more
       terse definitions. If you enter a key definition line with only
       and exactly one action code after the equals sign, it has a
       special meaning. If the code (numeric or symbolic) is not an
       ASCII letter, it means the code is implicitly replicated through
       all columns being defined.  If, on the other hand, the action
       code is an ASCII character in the range 'a', ..., 'z' or 'A',
       ..., 'Z' in the ASCII collating sequence, the following
       definitions are made for the different modifier combinations,
       provided these are actually being defined.  (The table lists the
       two possible cases: either the single action code is a lower case
       letter, denoted by 'x' or an upper case letter, denoted by 'Y'.)


           none   x              Y
           Shift  X              y
           AltGr  x              Y
                  X              y
                  Control_x      Control_y
                  Control_x      Control_y
                  Control_x      Control_y
                  Control_x      Control_y
           Alt    Meta_x         Meta_Y
                  Meta_X         Meta_y
                  Meta_x         Meta_Y
                  Meta_X         Meta_y
                  Meta_Control_x Meta_Control_y
                  Meta_Control_x Meta_Control_y
                  Meta_Control_x Meta_Control_y
                  Meta_Control_x Meta_Control_y


       All the previous forms of key definition lines always define all
       the M+1 possible modifier combinations being defined, whether the
       line actually contains that many action codes or not.  There is,
       however, a variation of the definition syntax for defining only
       single actions to a particular modifier combination of a key.
       This is especially useful, if you load a keymap which doesn't
       match your needs in only some modifier combinations, like
       AltGr+function keys. You can then make a small local file
       redefining only those modifier combinations and loading it after
       the main file.  The syntax of this form is:

       { plain | <modifier sequence> } keycode keynumber = keysym

       , e.g.,
              plain keycode 14 = BackSpace
              control alt keycode 83 = Boot
              alt keycode 105 = Decr_Console
              alt keycode 106 = Incr_Console
       Using "plain" will define only the base entry of a key (i.e. the
       one with no modifiers in effect) without affecting the bindings
       of other modifier combinations of that key.


       In addition to comments and key definition lines, a keymap can
       contain string definitions. These are used to define what each
       function key action code sends. The syntax of string definitions

              string keysym = "text"

       text can contain literal characters, octal character codes in the
       format of backslash followed by up to three octal digits, and the
       three escape sequences \n, \\, and \", for newline, backslash and
       quote, respectively.


       Then there may also be compose definitions. They have syntax

              compose 'char' 'char' to 'char'
       and describe how two bytes are combined to form a third one (when
       a dead accent or compose key is used).  This is used to get
       accented letters and the like on a standard keyboard.


       Various abbreviations can be used with kbd-0.96 and later.

       strings as usual
              Defines the usual values of the strings (but not the keys
              they are bound to).

       compose as usual for "iso-8859-1"
              Defines the usual compose combinations.

       To find out what keysyms there are available for use in keymaps,
       use the command

              dumpkeys --long-info

       Unfortunately, there is currently no description of what each
       symbol does. It has to be guessed from the name or figured out
       from the kernel sources.

EXAMPLES         top

       (Be careful to use a keymaps line, like the first line of
       `dumpkeys`, or "keymaps 0-15" or so.)

       The following entry exchanges the left Control key and the Caps
       Lock key on the keyboard:

              keycode  58 = Control
              keycode  29 = Caps_Lock

       Key number 58 is normally the Caps Lock key, and key number 29 is
       normally the Control key.

       The following entry sets the Shift and Caps Lock keys to behave
       more nicely, like in older typewriters. That is, pressing Caps
       Lock key once or more sets the keyboard in CapsLock state and
       pressing either of the Shift keys releases it.

              keycode  42 = Uncaps_Shift
              keycode  54 = Uncaps_Shift
              keycode  58 = Caps_On

       The following entry sets the layout of the edit pad in the
       enhanced keyboard to be more like that in the VT200 series

              keycode 102 = Insert
              keycode 104 = Remove
              keycode 107 = Prior
              shift keycode 107 = Scroll_Backward
              keycode 110 = Find
              keycode 111 = Select
              control alt   keycode 111 = Boot
              control altgr keycode 111 = Boot

       Here's an example to bind the string "du\ndf\n" to the key AltGr-
       D. We use the "spare" action code F100 not normally bound to any

              altgr keycode 32 = F100
              string F100 = "du\ndf\n"

SEE ALSO         top

       loadkeys(1), dumpkeys(1), showkey(1), xmodmap(1)

COLOPHON         top

       This page is part of the kbd (Linux keyboard tools) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this
       manual page, send it to  This page was
       obtained from the project's upstream Git repository
       ⟨⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-05-20.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

kbd                           24 April 1998                   KEYMAPS(5)

Pages that refer to this page: dumpkeys(1)loadkeys(1)showkey(1)