This is only an example, but I have just written a script to check the crontab to ensure that backups of databases are scheduled. This is a run of the mill task for an admin oriented perl programmer. For those unfamiliar with perl, it would show off many useful concepts, like hashes to keep track of what needs to be backed up and what is backed up; foreach loops to build and compare the hashes; string manipulation to pull names out of crontab lines; etc.
in reply to Plenty of Practical Perl Problems?
All sorts of monitoring scripts can help to prevent disasters, or help you deal with their consequences.