linux kill, killall

http://linux.byexamples.com/archives/157/kill-process-with-care/#comments

How to kill a process?

To kill a process, you need to know its process ID (PID). The easiest way to check is by ps with grep, let say I wanna check the PID of gaim.

=> ps aux | grep gaim

Let say it returns PID with numbers 5678, Then now you can kill and check with ps and grep again to confirm whether the process have successfully kill.

=> kill 5678

Alternatively, you can kill processes by specified process name using pkill, again I wanna kill gaim.

=> pkill gaim

How to force kill a process?

You can choose a signal to send to the process, checks the kill manual for available signals to send.

=> man kill

Usually if you process was unable to kill, first check whether you need to have root privilege to kill? certain process is instantiate by root, to kill you must have the same level of privilege.

=> sudo kill 5678

Second, try to kill with -1 and -2 before uses -9.

=> kill -1 5678

Okay, the process is really irritating, let me force kill it,

=> kill -9 5678

Some process may have multiple instances, killing the process one by one with PID is nightmare, so kill them all one shot!

=> killall gaim

Still there? grrrrrrrrrr!

=> sudo killall -9 gaim