CRON(8) CRON(8)
NAME
cron - clock daemon
SYNOPSIS
/etc/cron
DESCRIPTION
Cron executes commands at specified dates and times accord-
ing to the instructions in the file It should be run once
from rc(8).
Crontab entries are lines of seven fields separated by
blanks or tabs:
login minute hour day month weekday command
Login is the login name under whose userid and groupid the
command should be executed. The next five fields are inte-
ger patterns for
minute 0-59
hour 0-23
day of month 1-31
month of year 1-12
day of week 0-6; 0=Sunday
Each pattern may contain a number in the range above; two
numbers separated by a hyphen meaning an inclusive range; a
list of numbers separated by commas meaning any of the num-
bers; or an asterisk meaning all legal values.
The last field is a string to be executed by the shell,
after replacing `%' with newline.
It is wise to spread the times of activities to avoid bog-
ging the system down at favorite hours.
Cron examines crontab every minute.
EXAMPLES
daemon 17 3 * * * /usr/bin/calendar - # reminders at 0317
adm 15 4 1,15 * * ac -p | mail adm # bimonthly accounts
root 0 12 22-28 11 4 /etc/wall Time for Thanksgiving dinner
FILES
SEE ALSO
at(1)
BUGS
The behavior of `%' in crontab entries is nonstandard.
Strings following `%' should be delivered to the command as
CRON(8) CRON(8)
standard input.