Aragorn wrote:

> I seem to have run into another little mystery here for which neither the
> documentation nor Google provide any useful help...
>
> In the file */etc/conf.d/keymaps,* there is a variable /EXTENDED_KEYMAPS./
> By default it is set to "", but an alternative value underneath which is
> commented out lists "backspace keypad euro" as example values.
>
> Can anyone tell me what those values mean, or at least what "backspace"
> and "keypad" mean there? (I suppose I know what "euro" means.)

Whatever you put into EXTENDED_KEYMAPS is passed as an argument to loadkeys.
This is the relevant line from the /etc/init.d/keymaps script (which loads
the keymaps for the console only, not for X window):

ebegin "Loading key mappings"
if [[ -x /bin/loadkeys ]] ; then
[[ ${SET_WINDOWKEYS} == "yes" ]] && WINDOWKEYS_KEYMAP="windowkeys"
/bin/loadkeys -q ${WINDOWKEYS_KEYMAP} ${KEYMAP} \
${EXTENDED_KEYMAPS} > /dev/null
eend $? "Error loading key mappings"
else
eend 1 "/bin/loadkeys not found"
return 1
fi

Essentially, the arguments to loadkeys are filenames of console map files,
generally found under /usr/share/keymaps/<arch> (where <arch>, for normal
PCs - either x86 or amd64 - is "i386").

So, as an example, using this configuration:

KEYMAP="be-latin1"
EXTENDED_KEYMAPS="euro backspace keypad"

will result in the following command being executed by the initscript:

/bin/loadkeys -q be-latin1 euro backspace keypad

which will load the following keymap files:

/usr/share/keymaps/i386/azerty/be-latin1.map.gz
/usr/share/keymaps/i386/include/euro.map.gz
/usr/share/keymaps/i386/include/backspace.map.gz
/usr/share/keymaps/i386/include/keypad.map.gz

(You can do

ls /usr/share/keymaps/i386/{azerty,dvorak,fgGIod,include,qwerty,qwertz}

and see for yourself what keymaps are available)

The keymaps located in include/ are not full keymaps; they just define some
extra keys, like, for instance, the euro key or the backspace key, which
complement the main keymap. And yes, they are plain text files, so you can
see what they do (if not already apparent by their name). For example, this
is /usr/share/keymaps/i386/include/euro.map.gz:

$ zcat /usr/share/keymaps/i386/include/euro.map.gz
# Euro and cent
# [Say: "loadkeys euro" to get Euro and cent with Alt on the positions
# where many keyboards have E and C.
# To get it displayed, use a latin0 (i.e., latin9) font.]
alt keycode 18 = currency
alt keycode 46 = cent

So, using EXTRA_KEYMAPS="euro" will give you the "€" and "¢" symbols in
console, provided you use a font that can render them.

In my experience, using "backspace" in EXTRA_KEYMAPS is useless, since most
keymaps already define that key themselves.

Hope this helps.