keyboard - keyboard configuration file
The keyboard file describes the properties of the keyboard. It is read by setupcon(1) in order to configure the keyboard on the console. In Debian systems the default keyboard layout is described in /etc/default/keyboard and it is shared between X and the console.
The specification of the keyboard layout in the keyboard file is based on the XKB options XkbModel, XkbLayout, XkbVariant and XkbOptions. Unfortunately, there is little documentation how to use them. Description of all possible values for these options can be found in the file xorg.lst.
You might want to read The XKB Configuration Guide by Kamil Toman and Ivan U. Pascal:
Only one assignment is allowed per line. Comments (starting with #) are also allowed.
http://www.xfree86.org/current/XKB-Config.html Other possible readings are: http://pascal.tsu.ru/en/xkb/
The complete XKB-specification can be found on http://xfree86.org/current/XKBproto.pdf The file keyboard consists of variable settings in POSIX format: VARIABLE=VALUE
The following variables can be set.
XKBMODEL Specifies the XKB keyboard model name. Default: pc105 for most platforms.
XKBLAYOUT Specifies the XKB keyboard layout name. This is usually the country or language type of the keyboard. Default: us for most platforms
XKBVARIANT Specifies the XKB keyboard variant components. These can be used to further specify the keyboard layout details. Default: not set.
XKBOPTIONS Specifies the XKB keyboard option components. Options usually relate to the behavior of the special keys (<Shift>, <Control>, <Alt>, <CapsLock>, etc.) Default: not set.
BACKSPACE Determines the behavior of <BackSpace> and <Delete> keys on the console. Allowed values: bs, del and guess. In most cases you can specify guess here, in which case the current terminal settings and the kernel of your operating system will be used to determine the correct value. Value bs specifies VT100-conformant behavior: <BackSpace> will generate ^H (ASCII BS) and <Delete> will generate ^? (ASCII DEL). Value del specifies VT220-conformant behavior: <BackSpace> will generate ^? (ASCII DEL) and <Delete> will generate a special function sequence.
KMAP Usually this variable will be unset but if you dont want to use a XKB layout on the console, you can specify an alternative keymap here. Specify a file that is suitable as input for loadkeys(1) on Linux or for kbdcontrol(1) on FreeBSD.
The standard location of the keyboard file is /etc/default/keyboard. Description of all available keyboard models, layouts, variants and options is available in /usr/share/X11/xkb/rules/xorg.lst. In most cases, in /usr/share/keymaps/ or /usr/share/syscons/keymaps/ you will find several keymaps that can be used with the variable KMAP.
In Debian systems, changes in /etc/default/keyboard do not become immediately visible to X. You should either reboot the system, or use
udevadm trigger --subsystem-match=input --action=change
When a triple-layout is used, i.e. a layout with three XKB groups, then the group toggling happens in the following way: Group1 -> Group2 -> Group1 -> Group3.
On FreeBSD triple- and quadruple-layouts are not supported (only the first and the second layout are taken into account).
The option grp:shifts_toggle is not supported.
The following configuration will give you the standard US QWERTY layout (us). The key <Menu> will act as a compose key (compose:menu) and <CapsLock> will act as third control key (ctrl:nocaps).In the following configuration the right <Alt> key (grp:toggle) will toggle between US QWERTY layout (us) and Greek (gr) layout. The option grp_led:scroll is ignored on the console but in X in means to use the ScrollLock keyboard led as indicator for the current layout (US or Greek).
XKBLAYOUT=us XKBVARIANT= XKBOPTIONS=compose:menu,ctrl:nocaps
In the following configuration the <Control>+<Shift> key combination will toggle (grp:ctrl_shift_toggle) between French keyboard (fr) without dead keys (nodeadkeys) and British (gb) Dvorak (dvorak) keyboard. The right <Win> key will be a compose-key (compose:rwin) and the right <Alt> key will function as AltGr (lv3:lalt_switch).
XKBLAYOUT=us,gr XKBVARIANT= XKBOPTIONS=grp:toggle,grp_led:scroll
XKBLAYOUT=fr,gb XKBVARIANT=nodeadkeys,dvorak XKBOPTIONS=grp:ctrl_shift_toggle,compose:rwin,lv3:ralt_switch
setupcon(1), ckbcomp(1), console-setup(5), loadkeys(1), kbdcontrol(1)