Acccomplish Things While You're Gone!
A Primer on CROND
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.