Custom (X11/xkb) keyboard layout without being root

Published: Jun 6 2014

Updated: Jun 6 2014

Short tutorial about creating a custom keyboard layout without being root.

Configuration

In a directory, create a symbols/ subdirectory. In this subdirectory, create a custom file:

mkdir -p keyboard/symbols
sensible-editor keyboard/symbols/custom

In this file, create a new layout inheriting from the base layout of your choice:

partial alphanumeric_keys
xkb_symbols "fr" {
    // This is the base layout you are inheriting:
    include "fr(oss)"

    // Overridden/new bindings goes here
}

Choose the behaviour of the Control/Shift/Alt/Lego/Menu keys:

Some versions of oss map right-control to access another group of symbols. This can be overriden with:

key <LCTL> { [ Control_L ] };
key <RCTL> { [ Control_R ] };

Use LWIN to serve another AltGr:

key <LWIN> {
  type[Group1]="ONE_LEVEL",
  symbols[Group1] = [ ISO_Level3_Shift ]
};
key <RALT> {
  type[Group1]="ONE_LEVEL",
  symbols[Group1] = [ ISO_Level3_Shift ]
};

Use RWIN as another Alt:

key <RWIN> { [ Alt_R, Meta_R ] };
key <LALT> { [ Alt_L, Meta_L ] };

Another group of keys:

Use the MENU and CAPS keys to access another group of symbols:

key <MENU>  {
  symbols[Group1]= [ Mode_switch  ],
  virtualMods= AltGr
};
key <CAPS>  {
  symbols[Group1]= [ Mode_switch  ],
  virtualMods= AltGr
};

It is now possible to assign 4 new symbols to each key:

// This is the D key:
key <AC03>  { symbols[Group2] = [ Greek_delta, Greek_DELTA, U2202, U2207 ] }; // δ Δ ∂ ∇

Using it

setxkbmap will only use the system config files. In order to use your custom configuration files without installing it in the system directory, you have to use xkbcmp:

cd keyboard/
setxkbmap custom fr -option -print | xkbcomp -I. - $DISPLAY

Notes:

If the -option argument it not used, the options will be inherited from the configuration stored in the root window (read with XkbRF_SetNamesProp).
The -I flag is used to add an include directory for the files.
When going through xkbcomp, the new configuration is not stored in the root window which might break the expectations of some programs (XkbRF_SetNamesProp).

Shell script

You can move this configuration in ~/.xkb and use this shell script:

#!/bin/sh
setxkbmap -option "" custom fr -print | xkbcomp -I"$HOME"/.xkb - $DISPLAY

or more generally:

#!/bin/sh
setxkbmap -option "" "$@" -print | xkbcomp -I"$HOME"/.xkb - $DISPLAY