Question

I need to implement a shell script that kills a process. The problem is that I need to do a conditional to be able to see if the process is running or not.

This is my code, but it is not working:

#!/bin/sh

if [ -x  "MY_PROCCESS_NAME"]; then
    killall MY_PROCCESS_NAME
else
    echo "Doesn't exist"
fi

This is the error:

line 3: [: missing `]'

Answer 1

to check if a process is running on mac os x you can use:

pid=$(ps -fe | grep 'process name' | grep -v grep | awk '{print $2}')

if you want to reduce the number of shell scripts you can enclose one of the characters of the name of the process in square brackets:

pid=$(ps -fe | grep '[p]rocess name' | awk '{print $2}')

combined in your test this would look like:

pid=$(ps -fe | grep '[p]rocess name' | awk '{print $2}')
if [[ -n $pid ]]; then
    kill $pid
else
    echo "Does not exist"
fi

it’s a little more complicated than you would need to do under linux as you generally have the ‘pgrep’ command, which is the rough equivalent of the ‘ps -fe | grep … | grep -v grep’