EMBED THIS RECORDING:
I recorded this `flock crontab != cronoverlap` shellsession because I had many unfortunate
situations where my cronjobs would overlap.
Normally cronjobs will start every X minutes/hours e.g., but what if a job takes longer?
Your server can go bananas when a cronjob hangs e.g.
Anyways, there's flock:
flock -w 0 /tmp/.mylockfile <yourcmd>
Previously I tried start-stop-daemon (debian) and daemon (centos) but this is the most portable
solution I could find.