Check if process is running Mac OS X then execute code

Question

I am creating a script which clears the cache for Google Chrome. However, I would like to check if Chrome is open and if so not run the code but if it isn't then it will execute the code. I can see that the Process Name is Google Chrome but the code doesn't work.

This is what I have done so far. What am I doing wrong?

SERVICE='Google Chrome'

if ps ax | grep -v grep | grep $SERVICE
then
    RUNS THE CODE
else
    echo "PLEASE CLOSE GOOGLE CHROME"
fi

Any help would be appreciated :)

Solution 1

As @StéphaneChazelas mentions, you can use pgrep - from the man page:

The pgrep command searches the process table on the running system and prints the process IDs of all processes that match the criteria given on the command line.

SERVICE='Google Chrome'

if pgrep -xq -- "${SERVICE}"; then
    echo running
else
    echo not running
fi

Solution 2

You need to quote "$SERVICE":

SERVICE='Google Chrome'

if ps ax | grep -v grep | grep "${SERVICE}" &> /dev/null; then
    echo running
else
    echo not running
fi

Comments

[Stéphane Chazelas]

Or just pgrep -f "$SERVICE". Note that it would return true as long as there's a process that has Google Chrome in its argument list, so is not fool-proof and generally not the right way to check that a service is running.

[Digital Trauma]

@StéphaneChazelas why specify the -f at all? -f Match against full argument lists. The default is to match against process names. Without the -f I think we just match against process name which is what is needed here, right?

[Stéphane Chazelas]

Or pgrep -xq -- "$SERVICE". Note that not all pgrep implementations support -q.

[Digital Trauma]

@StéphaneChazelas Yes, -x is nicer. I'm assuming the OSX pgrep, since that is how the question was tagged.