How to kill non-responsive GUI task under Unity?

I am searching for a newuser-friendly way to kill non-responsive GUI applications under Unity.

I looked over the shoulder of a new Unity user who tried to use gscan2pdf - and gscan2pdf seems to be really broken - after not much tinkering it consumed much CPU und memory, the PC began trashing and the user needed to immediately kill the gscan2pdf GUI which was full-screen, non-responsive and had the focus.

Ok, I know some ways how to do it:

• Hit Alt+F2 and type xkill -> select the window


• Hit Alt+F2 start xterm, use top or pgrep and then kill PID or directly use pkill

Both are ways which are not very intuitive for GUI centric users.

Is there some Unity shortcut to get something like xkill?

Or is the best GUI-way to add a top-like GUI to the Unity-starter? And which one?

You could create a keyboard shortcut for xkill.

1. Type keyboard in the Unity Dash and click the icon. Select the
   shortcuts tab.




2. There, scroll down to the custom shortcuts section and click on the
   + button




3. Now name your shortcut something and let the command be xkill and then click ok.



4. Finally click on the xkill shortcut and press the desired key-combo to assign a shortcut to it and that's it :)


5. Pressing the keyboard shortcut will activate xkill whenever you need it.