I have been using this script for a long time (maybe 13 years) with only very slight changes. It was probably one of the first cool ideas I had for a way to track laptops issued to employees that might possibly be stolen. Granted, today, we use full disk encryption and other cool things that almost makes this script obsolete….but in the event something does get stolen, we can always track it.
The script only requires a crontab entry and a way to send mail (I use ssmtp btw).