I What's CROND?

• A daemon that initiates other programs at specific times, as indicated by a pattern.
• Ships with just about every Linux distribution, and is available from the 'net. Installation is trivial.
• An accepted UNIX utility (on par with vi). It's very small, under 100 Kb.

II. What's CROND (I mean crond) used for?

• Repetitive, production processing.
• Backups, cleanups, purges, merges, or other housekeeping tasks. - Red Hat ships with a few (for rpm-db updates)
• Things you might forget, but are essential to the health of the system. - Red Hat has at least one (man page cleanups) - The KLUG meeting notice is a "cron job".

III. Outline of the principles

• A daemon that runs all the time, checks time specification files every minute, runs as root.
• Time/program specification file syntax -- parse and task initiator.
• Notifier/output spooler -- delivery via email.
• Editing environment for "crontab" files.