Linux 4 Ways to Kill a Process – kill, killall, pkill, xkill

1. Kill Command – Kill the process by specifying its PID
2. Killall Command – Kill processes by name
3. Pkill Command – Send signal to the process based on its name
4. Xkill Command – kill a client by X resource

Ref: http://www.thegeekstuff.com/2009/12/4-ways-to-kill-a-process-kill-killall-pkill-xkill/#more-2547
http://unixhelp.ed.ac.uk/CGI/man-cgi?signal+7