How to implement alternate zap key idea (was: Re: Poll: Should Xorg change from using Ctrl+Alt+Backspace to something harder for users to press by accident?)

Jason Spiro jasonspiro4 at
Mon Sep 22 21:39:49 PDT 2008

Peter Hutterer <peter.hutterer <at>> wrote:
> driver kbd: hardcodes Ctrl + Alt + Backspace. (IMHO that's a bug anyway)
> driver evdev: the XKB map decides what happens.
> In the latter case, all you have to do is change the xkb map. If you can
> convice svu to add it to xkeyboard-config, you only need to supply the right
> option and you're done with it.

Thanks for the info.  1. So I guess when using evdev, a way to implement my
Ctrl+Alt+Bksp then Ctrl+Alt+Y idea would be this?:  Ctrl+Alt+Bksp should latch
some new modifier called ctrl_alt_bksp_was_pressed, and Ctrl+Alt+Y should zap X
only when that modifier is latched.  Would that work?

As for the Ctrl+K+X idea (which I don't know is as safe; 2. is it possible that
a heavy pet sitting on the keyboard and depressing all keys at once could cause
X to think Ctrl+K+X was pressed?), 3. are kbd and evdev each able to detect such
a key combination?  4. Are the majority of PS/2 and USB keyboards able to
transmit such three-key combos reliably?  5. Do most users know how to press
multi-letter key combinations?

> I'm not quite sure what the poll will achieve here.

I was hoping it could provide extra backing for my assertion that
Control-Alt-Backspace is a bad choice of key combination.  In fact, it hasn't. 
Plus, due to the psychological effect called "groupthink", people who would have
said "yes" are now less likely to admit it to the entire list, since IIRC three
have already said "no" and only one (me) has said "yes".  :(

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