xsetwacom set "Wacom Intuos S Pad pad" Button 1 key F8
xsetwacom set "Wacom Intuos S Pad pad" Button 2 key shift F9
xsetwacom set "Wacom Intuos S Pad pad" Button 3 key ctrl F9
xsetwacom set "Wacom Intuos S Pad pad" Button 8 key F9