Name
crontab
Synopsis
crontab [file
] crontaboptions
[user
]
View, install, or uninstall your current
crontab file. On Mac OS X and GNU/Linux, a
privileged user can run crontab
for another user by supplying -u
user. On Solaris, supply
user following one of -e
,
-l
, or -r
.
A crontab file is a list of commands, one per line, that executes automatically at a given time. Numbers are supplied before each command to specify the execution time. The numbers appear in five fields, as follows:
Minute 0-59 Hour 0-23 Day of month 1-31 Month 1-12 Day of week 0-6, with 0 = Sunday
Use a comma between multiple values, a hyphen to indicate a range, and an asterisk to indicate all possible values. For example, assuming the crontab entries below:
59 3 * * 5 find / -print |backup_program
0 0 1,15 * * echo "Timesheets due" | mailuser
The first command backs up the system files every Friday at 3:59 a.m., and the second command mails a reminder on the 1st and 15th of each month.
Common Options
-
-e
Edit the user’s current crontab file (or create one).
-
-l
List the user’s file in the crontab directory.
-
-r
Delete the user’s file in the crontab directory.
GNU/Linux and Mac OS X Option
-
-u
user
Indicate which user’s crontab file will be acted upon.
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