I’m trying to block the function keys (F1-F12) on my Linux system using xkb and xmodmap, but so far, I haven’t had any success. Despite setting the keys to NoSymbol, the function keys continue to work, and system actions (like F1 opening help, F5 refreshing, etc.) are still triggered.

I would like to completely disable the function keys, including their default behaviors and any Fn + Function Key combinations.

i already tried modify /xkb/symbols/pc file relevant part to:

key <FK01> { [ NoSymbol, NoSymbol, NoSymbol, NoSymbol ] };   // F1
key <FK02> { [ NoSymbol, NoSymbol, NoSymbol, NoSymbol ] };   // F2
key <FK03> { [ NoSymbol, NoSymbol, NoSymbol, NoSymbol ] };   // F3

Despite this configuration, the function keys still work as expected (e.g., F1 opens help, F5 refreshes the page, etc.).

I’ve also tried using xmodmap

xmodmap -e "keycode 67 = NoSymbol"   # F1
xmodmap -e "keycode 68 = NoSymbol"   # F2
xmodmap -e "keycode 69 = NoSymbol"   # F3