Man Linux: Main Page and Category List


       keymaps - keyboard table descriptions for loadkeys and dumpkeys


       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

       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 (\).


       A keymap can include other keymaps using the syntax

              include "pathname"


       A character set definition line is of the form:

              charset <charset>

       Where  <charset>  is one of the currently supported charsets, which can
       be found using dumpkeys --help.  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
       Latin1  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 like

              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 8 modifiers. These modifiers  are  labeled  (completely
       arbitrarily)  Shift,  AltGr,  Control,  Alt,  ShiftL, ShiftR, CtrlL and
       CtrlR.  Each of these modifiers has an associated weight  of  power  of
       two according to the following table:

              modifier                weight

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

       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  or  symbolic
       notation.  The numeric notations use the same format as with keynumber.
       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.

       If you do need to use numeric notations, comment  those  lines  heavily
       and  add  a  comment at the top of the file. This will save your sanity
       (if any) later. If this file should happen to get  past  your  personal
       system,  it may also save you much pain and embarrassment. Also, please
       file a bug report against loadkeys noting the need for a 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’.)

           modifier                symbol

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

              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, the keymap files can
       contain string definitions. These are used to define what each function
       key action code sends. The syntax of string definitions is:

              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,


       Then there may also be compose definitions. They have syntax

              composechar’ ’chartochar’
       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.

              Whenever  some  combination  is  defined as an ASCII symbol, and
              there is a corresponding  Alt  keymap,  define  by  default  the
              corresponding Alt combination as Meta_value.

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


       (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 terminals:

              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 key.

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


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