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