How do I make sure my bash script isn't already running?

Question

I have a bash script I want to run every 5 minutes from cron... but there\'s a chance the previous run of the script isn\'t done yet... in this case, i want the new run to j

Answer 1

You can always just:

 if ps -e -o cmd | grep scriptname > /dev/null; then 
     exit
 fi

But I like the lockfile myself, so I wouldn't do this without the lock file as well.