Cron
Not all implementations include a crond(8) command, but all do include crontab(1).
Contents
Installation
There are multiple implementations.
Arch offers cronie and fcron packages but promoted timers instead.
Fedora offers cronie only; it is a Red Hat initiative.
Debian offers a custom distribution of Vixie cron, with plans to phase it out for cronie.
Busybox Crond
The !BusyBox implementation of Cron (crond(8)) recommends a layer of indirection through named directories. The default configuration runs these tasks:
# min hour day month weekday command */15 * * * * run-parts /etc/periodic/15min 0 * * * * run-parts /etc/periodic/hourly 0 2 * * * run-parts /etc/periodic/daily 0 3 * * 6 run-parts /etc/periodic/weekly 0 5 1 * * run-parts /etc/periodic/monthly
Any scripts in /etc/periodic/hourly will be run on the hourly mark every hour. This is considered preferable to installing a new cronjob.