UNIX for Dummies Questions & Answers

Hi Guys

May I know where can I find information about crontab, how to use it, examples etc? I really don't know how does it works and how to use it. Thanks!

Now I give a example:
5 18 * * 1-5 /usr/lib/sa/sa2 -s 8:00 -e 18:01 -i 1200 -A

and I give some comment:
the first column is miniue [0-59];
the second is hour[0-23];
the third is day[1-31];
the fouth is month[1-12];
the fifth is week[0-6] ,0 means sunday.
and the later is command that you want to run when time elapses.

for more information,you could use command "man crontab" in the UNIX shell.

Keep in mind crontab is specific to the user. This is not a GLOBAL setting for all!!!

One would presume you've looked at the man page?

The home directory for crontab is

/usr/spool/cron/crontabs


In this directory u will find two very important files namely

cron.allow and cron.deny

if your user id is present in cron.allow then u are eligible for setting a crontab ... if its present in cron.deny, then permission is denied and u have to contact your administrator to move your id to cron.allow.

-Nisha

Actually /etc/cron.d is main cron directory

/etc/cron.d/cron.allow
/etc/cron.d/cron.deny contain those files you mentioned above


/var/spool/cron/crontabs "is a spooling area for cron"