term% cat index.txt CRON(8) System Manager's Manual CRON(8)
NAME
cron - clock daemon
SYNOPSIS
/etc/cron
DESCRIPTION
Cron executes commands at specified dates and times according to the
instructions in the file /etc/crontab. Since cron never exits, it
should be executed only once, by running cron from the initialization
process through the file /etc/rc; see init(8).
Crontab consists of lines of seven fields each. The fields are sepa‐
rated by spaces or tabs. The first field specifies the user under
whose uid and gid the command should be executed. The next five are
integer patterns to specify the minute (0-59), hour (0-23), day of the
month (1-31), month of the year (1-12), and day of the week (1-7 with
1=Monday). Each of these patterns may contain a number in the range
above; two numbers separated by a minus meaning a range inclusive; a
list of numbers separated by commas meaning any of the numbers; or an
asterisk meaning all legal values. The seventh field is a string that
is executed by the shell at the specified times. A percent character
in this field is translated to a new-line character. Only the first
line (up to a % or end of line) of the command field is executed by the
Shell. The other lines are made available to the command as standard
input.
Crontab is examined by cron every minute.
FILES
/etc/crontab
CRON(8)