Computer Science


KEYMAPS(5)             Linux User's Manual             KEYMAPS(5)

NAME
       keymaps  -  keyboard  table  descriptions for loadkeys and
       dumpkeys

DESCRIPTION
       These files are used by loadkeys(1) to modify the transla-
       tion  tables used by the kernel keyboard driver and gener-
       ated 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 con-
       tinue to the end of the line. Anything  following  one  of
       these  characters  on that line is ignored. Note that com-
       ments 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
       A keymap can include other keymaps using the syntax

              include "pathname"

CHARSET DEFINITIONS
       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.

COMPLETE KEYCODE DEFINITIONS
       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,  boot-
       ing  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 mod-
       ifier keys, otherwise you can end up with an unusable key-
       board  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 for-
       mat  as  with  keynumber.  The symbolic notation resembles
       that used by xmodmap(1).  Notable differences are the num-
       ber   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  sup-
       ported  keyboard action in your kernel for which your cur-
       rent version of loadkeys(1) has no symbolic name.

       There is a number of short-hand notations to add readabil-
       ity  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, Con-
       trol+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 charac-
       ter  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

SINGLE MODIFIER DEFINITIONS
       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  espe-
       cially  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 affect-
       ing the bindings of other modifier  combinations  of  that
       key.

STRING DEFINITIONS
       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, respectively.

COMPOSE DEFINITIONS
       Then there may also be compose definitions. They have syn-
       tax

              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.

ABBREVIATIONS
       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 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 sources.

EXAMPLES
       (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  num-
       ber 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"

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

Console tools              09 Oct 1997                          1

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