Ch 10 Cron
TO scheduled particular Task
#service gpm stop
#service gpm start
Cron demon execute the schedule jobes.
It will be use 24 hours clock timing.
#crontab –e filename
(in that file we have to add contain by format)
1 2 3 4 5
min hours day of month month of year day of week.
(0-59) (0-23) (1-31) (1-12) (0-6)
or or
(jan-dec) (sun-sat)
(First three char is enough)
(to know the cron list)
#crontab –l
(to edit Cron entry )
#crontab –e
(To remove cron entry)
#crontab –r
min hours day of month month of year day of week.
*/2 */4 * * *
(*/2 means Aftre every 2 minutes ,*/4 Every four hours and only * means every year , every month )
#crontab –e
41 13 * * * /sbin/init6 >/dev/tty4
(in this schedule system will restart every day by 13:41 in
TTY4 terminal 4)
(To give user to run crontab command)
#crontab –e –u (username)
There are two files , what ever user wants to run cron needs
To be added in /etc/cron/allow , wise versa The users which
You wants to block from running Cron needs to added in /etc/cron.deny
/etc/cron.allow
/etc/cron.deny