Mdthbs

I have a numpad connected via USB and my goal is to be able to remap keys on that numpad so they can run custom commands or be mapped to other key combinations.

I have this in my .xbindkeysrc file:

~ $ cat .xbindkeysrc

"xte 'keydown Super_L' 'key Left' 'keyup Super_L'"

  m:0x10 + c:79 + Release

  Mod2 + KP_Home

This remaps the NUM 7 key (which normally prints 7) to Super_L + Left Arrow. That's great and it works, BUT FOR ALL KEYBOARDS, while my goal is to make it work only for the numpad.

Been searching how to do it, but the closest I got was to use xinput set-button-map. Unfortunately, this seems to only work for devices like mouses. I like tried fetching what the button map is for the numpad with xinput get-button-map [device id] but it just prints numbers from 1 to 7 and I definitely have more buttons on my keypad, so it doesn't necessarily make sense.

Any advice?

setxkbmap has the option to target a specific device (keyboard).

So you need to find the deviceID first, using xinput list

$ xinput list



⎣ Virtual core keyboard

...

↳   USB Keyboard     id=19  [slave  keyboard (3)]

Then query the setxkbmap config to see your device settings (I will use '19'):

$ setxkbmap -device 19 -print

xkb_keymap {

    xkb_keycodes  { include "evdev+aliases(qwerty)" };

    xkb_types     { include "complete"  };

    xkb_compat    { include "complete"  };

    xkb_symbols   { include "pc+us(euro)+us(intl):2+inet(evdev)"    };

    xkb_geometry  { include "pc(pc105)" };

};

The symbols is what we're looking for; these can be found in ls /usr/share/X11/xkb/symbols. The arguments refer to a subsection in the file, for example xkb_symbols "intl" {

To add any of the available options like for example, rupeesign, you
could do setxkbmap -device 19 -option rupeesign:4

to reset the options, use setxkbmap -device 19 -option without further arguments.

However, you want some custom configuration, and that is a bit more tricky, because simply adding a custom file in that folder and using it does not work.

So create some folders and create a tempfile with the current config.

mkdir -p ~/.config/xkb/symbols

cd ~/.config/xkb 

setxkbmap -device 19 -print > tempfile.txt

touch symbols/mysymbol

Edit tempfile.txt so it contains mysymbol(mymapping)

...

xkb_symbols   { include "pc+us(euro)+us(intl):2+inet(evdev)+mysymbol(mymapping)"   

Edit symbol/mysymbol any way you want, see /usr/share/X11/xkb/symbols for examples.
This one adds a Bitcoin symbol to num 7 key .

partial

xkb_symbols "mymapping" {

    key <AE07> { [  7,   &,   U20BF ]  };



};

Now, finally, to activate this mapping, use xkbcomp ( note -i 19 to set the device)

xkbcomp -i 19 -I$HOME/.config/xkb tempfile.txt $DISPLAY

(This will probably show some warning messages, but it still works)