how to make xmonad ignore the right alt key in Ubuntu

Question

How can I get xmonad to match the left alt key and not the right alt key? Ubuntu binds these both to mod1 in xmodmap.

Answer 1

You can look which keys are the mod keys with "xmodmap -pm". xmodmap also allows to change the mod key configuration. Just enter the apropiate keycodes into ~/.Xmodmap or ~/.xmodmaprc

To find out which keycode the right alt key emits start "xev" like this:

xev | grep -A2 --line-buffered '^KeyRelease' | sed -n '/keycode /s/^.*keycode \([0-9]*\)

Answer 2

Not sure about alt, but the xmonad config archive has an example that uses Super instead of alt:

import XMonad

main = xmonad defaultConfig
        { modMask = mod4Mask -- Use Super instead of Alt
        , terminal = "urxvt"
        -- more changes
        }

You'll need to compile the new config file, so you'll need haskell if you don't have it already.