Grabbing events on specific keys with X11 on Linux?

The normal way to do this is with XGrabKey(). It uses keycodes, but you wouldn't hardcode the keycode, you'd get it with XKeysymToKeycode(). To be more correct you'd also want to redo the grab when you get a MappingNotify (XMappingEvent).(Note, MappingNotify not MapNotify.) If there isn't a keysym for these keys - there probably isn't on old X versions, but hopefully newer X.

Org versions have one - then you just have to hardwire the keycode. Which won't be very robust or portable but probably works for everyone on Linux with the same hardware model.

The normal way to do this is with XGrabKey(). It uses keycodes, but you wouldn't hardcode the keycode, you'd get it with XKeysymToKeycode(). To be more correct you'd also want to redo the grab when you get a MappingNotify (XMappingEvent).(Note, MappingNotify, not MapNotify.) If there isn't a keysym for these keys - there probably isn't on old X versions, but hopefully newer X.

Org versions have one - then you just have to hardwire the keycode. Which won't be very robust or portable but probably works for everyone on Linux with the same hardware model.Be prepared that key grabs are global, so if you try to XGrabKey() and something else has already grabbed that key, you'll get an X error - by default that exits the program. Another quirk of XGrabKey() is that it grabs the key with a precise modifier set.

For example, to handle both with and without NumLock, you need to grab twice. See Global Hotkey with X11/Xlib In a normal Linux setup (if you wanted to get a feature like this into upstream projects), the desktop environments don't want lots of separate apps fighting over the key grabs and getting errors. So there will be some central coordination points, such as the window manager or a special daemon might do all the keybindings and forward commands to other processes as needed.

So you would probably want to look at patching the same upstream code that handles other special keys like this, if you were trying to get your feature integrated into distributions by default. Another thing to be aware of is the Xkb API, which is a lot more complicated. There is some brain-bending way to grab keys with Xkb but I don't know of any advantage to going that route.

If you haven't done that yet, familiarize yourself with xev. Start it, give it the focus, and press the keys, to see what's happening.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.