CRON(8) System Manager's Manual CRON(8)
NAME
cron - clock daemon
SYNOPSIS
cron
EXAMPLES
/usr/bin/cron # Use absolute path in /etc/rc
DESCRIPTION
Cron is clock daemon. It is typically started up by including the command /usr/bin/cron in the /etc/rc file. Once started, cron puts
itself in the background, so no & is needed. It runs forever, sleeping most of the time. Once a minute it wakes up and examines
/usr/lib/crontab to see if there is any work to do. If there is, the work is done. The entries of /usr/lib/crontab contain 6 elements
each. Some examples follow:
Min Hr Dat Mo DayCommand
* * * * * /usr/bin/date >/dev/log #print date every minute
0 * * * * /usr/bin/date >/dev/log #print date on the hour
30 4 * * 1-5 /bin/backup /dev/fd1 #do backup Mon-Fri at 0430
30 19 * * 1,3,5 /etc/backup /dev/fd1 #Mon, Wed, Fri at 1930
0 9 25 12 * /usr/bin/sing >/dev/log #Xmas morning at 0900 only
SEE ALSO
at(1).
CRON(8)
