crontab(5)crontab(5)Namecrontab - clock daemon table file
Syntax
/usr/lib/crontab
Description
The command executes at specified dates and times according to the
instructions in the file. The file consists of lines with six fields
each. The format for a line is as follows:
minute hour day month weekday command
The following list defines each field in the line:
minute (0-59) The exact minute that the command sequence executes.
hour (0-23) The hour of the day that the command sequence executes.
day (1-31) The day of the month that the command sequence executes.
month (1-12) The month of the year that the command sequence exe‐
cutes.
weekday (1-7) The day of the week that the command sequence executes.
Monday = 1, Tuesday = 2, and so forth.
command The complete command sequence variable that is to be
executed. Note that the command string must conform to
Bourne shell syntax.
The first five integer fields may be specified as follows:
· A single number in the specified range
· Two numbers separated by a minus, meaning a range inclusive
· A list of numbers separated by commas, meaning any of the numbers
· An asterisk meaning all legal values
The sixth field is a string that is executed by the shell at the speci‐
fied times. A percent sign (%) in this field is translated to a new-
line character. Only the first line of the command field, up to a per‐
cent sign (%) or end of line, is executed by the shell. The other
lines are made available to the command as standard input.
Examples
The following example is part of a file:
# periodic things
0,15,30,45 * * * * (echo '^M' `date`; echo '') >/dev/console
0,15,30,45 * * * * /usr/lib/atrun
# daily stuff
5 4 * * * sh /usr/adm/newsyslog
15 4 * * * ( cd /usr/preserve; find . -mtime +7 -a -exec rm -f {} \; )
20 4 * * * find /usr/msgs -mtime +21 -a ! -perm 444 -a ! -name bounds
-a -exec rm -f {} \;
# NOTE: The above line is wrapped.
# local cleanups
30 4 * * * find /usr/spool/mqueue -type f -mtime +5 -name df-exec rm {} \;
35 4 * * * find /usr/spool/mqueue -type f -mtime +5 -name tf-exec rm {} \;
40 4 * * * find /usr/spool/rwho -type f -mtime +21 -exec rm {} \;
#
# redirecting error output
0 17 * * 1,3,5 /bin/tar -cv /usr/sysads/smith > /dev/console 2>&1
#
FilesSee Alsosh(1), cron(8)
Guide to System Environment Setup
crontab(5)
