XKeyller is a very simple C application for X11 that uses XInput to register a global shortcut that, once pressed, will kill whatever process owns the foreground window and resets the graphics mode. This is useful mainly when it comes to games that go fullscreen, grab global input and then go and freeze themselves.
To install XKeyller simply:
- Download the source code
- Make sure xrandr and xkill are available
- Make sure you have the Xorg development files and GCC installed
- Uncompress the tarball above somewhere and type make
- Copy the xkeyller file to /usr/local/bin (or wherever you put custom binary files)
- Run the program before you play the game or install it permanently by placing it somewhere in your $HOME/.xinitrc file before you start your window manager (make sure you call it as a background process with xkeyller &, otherwise it'll just block the startup process)
- Press Ctrl + Alt + K to kill the application that created the current foreground window
In Debian and derivatives the above can probably be installed with the x11-server-utils, xorg-dev, make and gcc packages.
Alternatively you can download a prebuilt binary for x86_64 Linux.