topic Re: How to schedule work in every two hours? two days? etc in Operating System - Linux

How to schedule work in every two hours? two days? etc

frederick van targero_1 — Sun, 19 Sep 2004 22:08:41 GMT

I only knew to schedule system work in every one hour,one day,one week by cron, but actually have no idear in every two, or three.
Can cron do on this way? how?

thanks for your tips
Fredeirck van targero

Re: How to schedule work in every two hours? two days? etc

Steven E. Protter — Sun, 19 Sep 2004 22:31:34 GMT

No problem at all

30 4,16 * * * /usr/contrib/bin/mirror.sites 2>&1 | mail -s "merijn mirror" your@mail.com

that does a job at 4 am and 4 pm 20 minutes after the hour

change it to:

30 0,2,4,6,9,10,12,14,16,18,20,22 * * * /usr/contrib/bin/mirror.sites 2>&1 | mail -s "merijn mirror" your@mail.com

Now the job runs every two hours in this case at 30 minutes after the hour

The next feild is day of the mont, that asterisk after the 22

pick your days again

30 4 2,4,6,8,10 * * /usr/contrib/bin/mirror.sites 2>&1 | mail -s "merijn mirror" your@mai.com

This runs a job every two days the first 10 days of the month at 4:30 a.m.

All this is fron the wonderful man crontab

My examples email the output as well.

SEP

Re: How to schedule work in every two hours? two days? etc

Muthukumar_5 — Mon, 20 Sep 2004 00:42:58 GMT

Based on the following setting's,
minute 0-59
hour 0-23
day of month 1-31
month 1-12 (or names, see below)
day of week 0-7 (0 or 7 is Sun, or use names)

we can schedule the task execution on cron jobs.

To execute every two hours of one task the,

0 0,2,4,6,8,10,12,14,16,18,20,22 * * * command > (redirection)

Example:
0 0,2,4,6,8,10,12,14,16,18,20,22 * * * uname -a > 1>/tmp/uname.log 2>&1

To excute it on two days once then,
0 10 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29 * * uname -a > 1>/tmp/uname.log 2>&1

It will execute the task at 10.00 on 1,3,.. days of everymonth

Depends upon the setting we can execute tasks with cron.

Re: How to schedule work in every two hours? two days? etc

Stuart Browne — Mon, 20 Sep 2004 00:43:56 GMT

Most modern linux based cron's have the ability first introduced with Vixie cron, and that is:

*/

i.e. to perform something every 2 hours, isntead of having a comma-separated-list like SEP suggests (there's nothing wrong with that btw):

15 */2 * * * /path/to/command

Which translates to the comma-separated-list of 0,2,4,6,8,10,12,14,16,18,20,22 - every 2 hours.

It works with all fields in the time specifier.

Re: How to schedule work in every two hours? two days? etc

Senthilmurugan — Tue, 21 Sep 2004 08:50:29 GMT

Cron do the job with the following format:

minute 0-59
hour 0-23
day of month 1-31
month 1-12 (or names)
day of week 0-7 (0 or 7 is Sun, or use names)

If you want to schedule a work for every 2 hour s you can do that by

* */2 * * * /PATH/TO/COMMAND

To schedule for every 2 days:
* * */2 * * /PATH/TO/COMMAND

See "#man 5 crontab" for more details.

Regards,
Senthil Murugan