Tuesday, October 21, 2003

Crontab @reboot

From the "they didn't have that in BSD 4.2 so I didn't know about it" department, a handy feature in Vixie cron: the @reboot option. It means run once at restart, an alternative to /etc/init.d for ordinary users. Vixie cron has other useful features:
@reboot Run once, at startup.
@yearly Run once a year, "0 0 1 1 *".
@monthly Run once a month, "0 0 1 * *".
@weekly Run once a week, "0 0 * * 0".
@daily Run once a day, "0 0 * * *".
@hourly Run once an hour, "0 * * * *".

This has been available since 1994 but it doesn't show up in RedHat or Mandrake man pages. It does show up in Debian.

Jeremy Zawodny mentions this as well.