How can I make a bash command run periodically?

Question

I want to execute a script and have it run a command every x minutes.

Also any general advice on any resources for learning bash scripting could be really cool. I us

Answer 1

Avoiding Time Drift

Here's what I do to remove the time it takes for the command to run and still stay on schedule:

#One-liner to execute a command every 600 seconds avoiding time drift
#Runs the command at each multiple of :10 minutes

while sleep $(echo 600-`date "+%s"`%600 | bc); do ls; done

This will drift off by no more than one second. Then it will snap back in sync with the clock. If you need something with less than 1 second drift and your sleep command supports floating point numbers, try adding including nanoseconds in the calculation like this

while sleep $(echo 6-`date "+%s.%N"`%6 | bc); do date '+%FT%T.%N'; done