xstdcmap

xstdcmap [-help] [-version] [-verbose] [-quiet] [-noxdefaults] [-file filename] [-output filename] [-dump filename] [-merge filename]

-help
    Displays help message.

-version
    Prints the version number of xstdcmap.

-verbose
    Enables verbose output.

-quiet
    Suppresses non-error output.

-noxdefaults
    Ignores the standard X defaults files.

-file filename
    Specifies the input .kmap filename. Defaults to stdin if omitted.

-output filename
    Specifies the output filename for the compiled keymap. Defaults to XKeysymDB if omitted.

-dump filename
    Dumps the parsed keymap to the specified file in a human-readable format.

-merge filename
    Merges the contents of the specified file into the keymap before compilation.

xstdcmap is a utility that compiles keyboard mapping tables suitable for use with X Window System servers and related utilities. It reads keyboard layout definitions from .kmap files, which describe how physical keys are mapped to keycodes and then to keysyms (symbolic names for keys). This process involves several steps including reading the kmap file, resolving symbolic references, applying modifiers, and generating an optimized representation of the keyboard map.
The compiled output, typically named XKeysymDB, is then used by X servers and clients to interpret keyboard input. This allows users to customize their keyboard layout to suit their language, preferences, or specific application needs. Without a properly configured keymap, keyboard input would be uninterpretable to the X server. xstdcmap plays a vital role in translating raw keyboard events into meaningful actions within the X Window System. Improper configuration can lead to incorrect key assignments or unexpected behavior.

The format of the .kmap files can be complex and requires careful attention to syntax. Errors in the .kmap file can lead to compilation failures or unexpected behavior. The X server needs to be restarted or reconfigured to load the new XKeysymDB after it is generated by xstdcmap.

The xstdcmap command exits with a status of 0 on success and a non-zero value on failure, usually indicating an error in the input .kmap file.

XKeysymDB - The compiled keyboard mapping database.
/usr/lib/X11/xkb/symbols - Commonly used directory for keyboard symbols.

xmodmap(1), setxkbmap(1)