Executes a script only if it isn't already running.

cronpod.sh

#!/bin/bash

isrunning=$(ps -ef | grep -v grep | grep "podcast.sh" | wc -l)

if [ "$isrunning" -gt "0" ]; then
        echo "[ALREADY RUNNING]"
        exit 0
else
        sudo /home/[your username]/podcast.sh
        exit 0
fi