I'd like to swap some keys but only in external keyboard. Is this possible with xmodmap?
I've found this question: Can I Xmodmap only a specific device? but it refers only to mouse.
that "The Xmodmap/Setxkbmap Method ... changes how X handles the keycodes it receives" so one could think that it's not possible, but I can call:
setxkbmap -device <device_id> -variant dvorak
and I obtain (partially) my desired result. So I have dvorak layout on external and "basic"=qwerty on my laptop keyboard. And I'd like to have my custom layout on external keyboard.