file] crontab [-u
Runs crontab on your current crontab file, or specifies a crontab
file to add to the crontab directory. A privileged user can run crontab for another user by supplying -u
user before any of the other options.
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 following crontab entries below:
59 3 * * 5 find / -print | backup_program 0 0 1,15 * * echo "Timesheets due" | mail user
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.
Edit the user's current crontab file (or create one).
List the user's file in the crontab directory.
Delete the user's file in the crontab directory.