Kill a process if it exists

Question

I want to kill all instruments processes that are running. I am using this:

sudo killall instruments

I am using this in a script and sometimes the process is not running and it stops my script saying there are no processes with that name that are running.

How can I check if a particular process is running? Instruments in my case.

Answer 1

sudo killall instruments 2>/dev/null

isn't enough?

Answer 2

If your script is terminating, you have most likely enabled set -e, to exit when a command fails.

If you don't care about the status, you can just append || true to the command:

sudo killall instruments || true

Answer 3

You can use pgrep <proc> to search for a process named <proc>

if pgrep instruments &> /dev/null ; then sudo killall instruments ; fi