NAME

       Compose - X client mappings for multi-key input sequences

DESCRIPTION

       The  X  library,  libX11,  provides  a  simple  input  method  for characters beyond those
       represented on typical keyboards using sequences of key strokes that are combined to enter
       a single character.

       The compose file is searched for in  the following order:

       -      If  the environment variable $XCOMPOSEFILE is set, its value is used as the name of
              the Compose file.

       -      If the user's home directory has a file named .XCompose, it is used as the  Compose
              file.

       -      The  system  provided  compose file is used by mapping the locale to a compose file
              from the list in /usr/share/X11/locale/compose.dir.

       Compose files can use an "include" instruction.  This allows  local  modifications  to  be
       made  to  existing  compose  files  without  including  all  of the content directly.  For
       example, the system's iso8859-1 compose file can be included with a line like this:
           include "%S/iso8859-1/Compose"

       There are several substitutions that  can  be  made  in  the  file  name  of  the  include
       instruction:

       %H  expands to the user's home directory (the $HOME environment variable)

       %L  expands    to    the    name    of   the   locale   specific   Compose   file   (i.e.,
           "/usr/share/X11/locale/<localename>/Compose")

       %S  expands  to  the  name  of   the   system   directory   for   Compose   files   (i.e.,
           "/usr/share/X11/locale")

       For example, you can include in your compose file the default Compose file by using:
              include "%L"
       and  then  rewrite  only  the few rules that you need to change.  New compose rules can be
       added, and previous ones replaced.

FILE FORMAT

       Compose files are plain text files, with  a  separate  line  for  each  compose  sequence.
       Comments begin with # characters.   Each compose sequence specifies one or more events and
       a resulting input sequence, with an optional comment at the end of the line:
              EVENT [EVENT...] : RESULT [# COMMENT]

       Each event consists of a specified input keysym, and optional modifier states:
              [([!] ([~] MODIFIER)...) | None] <keysym>

       If the modifier list is preceded by "!" it must match exactly.  MODIFIER  may  be  one  of
       Ctrl, Lock, Caps, Shift, Alt or Meta.  Each modifier may be preceded by a "~" character to
       indicate that the modifier must not be present. If "None" is specified, no modifier may be
       present.

       The  result  specifies a string, keysym, or both, that the X client receives as input when
       the sequence of events is input:
              "STRING" | keysym | "STRING" keysym

       Keysyms are specified without the XK_ prefix.

       Strings may be direct text encoded in the locale for which the compose file is to be used,
       or  an  escaped octal or hexadecimal character code.   Octal codes are specified as "\123"
       and hexadecimal codes as "\0x123a".  It is not necessary to specify in the right part of a
       rule  a  locale  encoded string in addition to the keysym name.  If the string is omitted,
       Xlib figures it out from the keysym according to the current  locale.   I.e.,  if  a  rule
       looks like:
              <dead_grave> <A> : "\300" Agrave
       the  result of the composition is always the letter with the "\300" code.  But if the rule
       is:
              <dead_grave> <A> : Agrave
       the result depends on how Agrave is mapped in the current locale.

ENVIRONMENT

       XCOMPOSEFILE
              File to use for compose sequences.

       XCOMPOSECACHE
              Directory to use for caching compiled compose files.

FILES

       $HOME/.XCompose
              User default compose file if XCOMPOSEFILE is not set.

       /usr/share/X11/locale/compose.dir
              File listing the compose file path to use for each locale.

       /usr/share/X11/locale/<localemapping>/Compose
              System default compose file for the locale, mapped via compose.dir.

       /var/cache/libx11/compose/
              System-wide cache directory for compiled compose files.

       $HOME/.compose-cache/
              Per-user cache directory for compiled compose files.

SEE ALSO

       XLookupString(3),    XmbLookupString(3),     XwcLookupString(3),     Xutf8LookupString(3),
       mkcomposecache(1), locale(7).
       Xlib - C Language X Interface