topic Re: Cron every 2 mins in Operating System - HP-UX

Cron every 2 mins

Dewa Negara_4 — Tue, 03 Apr 2007 22:39:10 GMT

Hi All,

Sorry to ask a basic question. How can we run cron every 2 mins? Should list such 2,4,6,8,etc * * * *? Is there any better way?

Pls help.
Thanks and Best regards,
Negara

Re: Cron every 2 mins

A. Clay Stephenson — Tue, 03 Apr 2007 23:00:30 GMT

That's the way it is done. Some flavors of "improved" UNIX allow more flexibility but stick with the standard syntax and your crontab entries will work everywhere. Now have you considered what happens if for some reason the previous cron job is still running when the new one fires off?

Re: Cron every 2 mins

Patrick Wallek — Tue, 03 Apr 2007 23:01:57 GMT

To run every 2 minutes, yes you need to list ALL even (or odd) numbered minutes.

Another way to do it would be via 'at'. At the end of your script you do an 'at scriptname now + 2 minutes' 'man at' for more information.

# cat script
#!/usr/bin/sh
do stuff
do more stuff
do even more stuff
at /dir/script now +2 minutes

Re: Cron every 2 mins

Yogeeraj_1 — Wed, 04 Apr 2007 00:29:31 GMT

hi Negara,

the most easy and dull way to do it is:
#***************************************
00 * * * * /home/yogeeraj/myscript.sh
02 * * * * /home/yogeeraj/myscript.sh
04 * * * * /home/yogeeraj/myscript.sh
06 * * * * /home/yogeeraj/myscript.sh
..
50 * * * * /home/yogeeraj/myscript.sh
52 * * * * /home/yogeeraj/myscript.sh
54 * * * * /home/yogeeraj/myscript.sh
56 * * * * /home/yogeeraj/myscript.sh
58 * * * * /home/yogeeraj/myscript.sh
#***************************************
# min|hour |day |month|day |script
# | |of mo| |of wk|
#----|-----|-----|-----|-----|-----------

kind regards
yogeeraj

Re: Cron every 2 mins

Victor Fridyev — Wed, 04 Apr 2007 02:31:08 GMT

Hi,

You can run the script every minute, but to put into the script the following:

typeset -i N=0
N=$(date +%m)%2
if [ $N -ne 0 ]; then
exit
fi
#Your script etc

HTH

Re: Cron every 2 mins

Victor Fridyev — Wed, 04 Apr 2007 03:22:01 GMT

Oops, sorry

There is a mistake in date format.

typeset -i N=0
N=$(date +%M)%2
if [ $N -ne 0 ]; then
exit
fi

According to the condition the script will exit every odd minute and will work every even minute.

HTH

Re: Cron every 2 mins

Peter Nikitka — Wed, 04 Apr 2007 06:00:32 GMT

Hi,

you have to setup your cronjob every minute, but can prepend a one-liner to skip the add minute:
* * * * * [ $(date '+\%M 2\%\%p' | dc) -eq 1 ] || /path/2your/your-cron-script

The above construct will NOT have an exit status != 0 for skipped minutes.

mfG Peter

Re: Cron every 2 mins

Dewa Negara_4 — Wed, 04 Apr 2007 21:57:33 GMT

Hi All,

It looks fine to me now. Thanks alot for all your help.

Best Regards,
Negara

Re: Cron every 2 mins

Khashru — Wed, 04 Apr 2007 23:06:45 GMT

Change in your script so that it runs in alternate minute and run that script once every hour.