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How To Prevent Someone From Executing xkill

From wikipedia entry:

Xkill is a utility program distributed with the X Window System that instructs the X server to forcefully terminate its connection to a client, thus "killing" the client.

Someone at id-ubuntu mailing list asked how to prevent someone from executing xkill. After reading this, my evil mind popped a solution >:).

My strategy is rather simple, you rename that xkill and move it somewhere else and put a script in place of xkill. Here's the run down:

1. rename xkill and move it somewhere else: sudo mv /usr/bin/xkill /etc/init.d/llikx_hide
2. put a script in place of xkill:

   sudo touch /usr/bin/xkill
   sudo chmod 555 /usr/bin/xkill
   sudo nano /usr/bin/xkill
   

   Put this script:

   #!/bin/bash
   
   logger "I'm trying to execute xkill";//logger will automatically save user who execute logger
   zenity --info --text "What are you doing?\nxkill execution is locked and logged\!" --title "Operation failed";
   

There you go. Everytime someone trying to execure xkill, they will see popup window.