CRON job still running?

Shell Programming and Scripting
1

Hi All,

I am writing a script that will eventually be executed by a cron job every 15 minutes. I want to make sure that my logic/script doesn't get executed if a previous job is still running. What would be the best way to handle that scenario? I was thinking to make my script create a temporary file once it starts and then remove it at the very end before exit. In this case I can always check if that temp file exist which will mean that the script is still running.
Is there a more elegant way to do this?

Thanks

2

I'd rather write the PID of your cronscript to that tempfile, so you can check right away if the process is still running or not, by matching ps $(cat tempfile) .

So in your cron script you do something like:

doit=false
[[ ! -f tempfile ]] && doit=true
[[ -f tempfile ]] && [[ ! $(ps $(cat tempfile) ]] && doit=true

if [[ $doit ]];then
      echo $$ > tempfile

      echo "your code"

      rm -f tempfile
fi

Hope this helps

NOTE: For cron scripts you need to write full paths to commands, not like this example!

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