[SOLVED] Confused with cron

dinakumar12 · 04-18-2011, 05:52 AM

Hi all,

I have a cron job like this.

04 07 17 04 02 sh -x myscript

this means the file myscript should be executed when the server date comes to Apr 17 on Tuesday at 07 04 am.

But the file myscript runs on every tuesday of April month. Whats wrong with cron i am very confused. Your suggestions please.

Thanks&regards,
Dinesh.

jhcaiced · 04-18-2011, 06:07 AM

Hi,

Try reading the man page for the cron file format

man 5 crontab

The format is:

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)

Best regards,

dinakumar12 · 04-18-2011, 06:14 AM

hi,

Thanks i did that, But no improvement in my problem.

michaelk · 04-18-2011, 06:49 AM

FYI

Quote:

Note: The day of a command's execution can be specified by two fields --
day of month, and day of week. If both fields are restricted (ie, are
not *), the command will be run when either field matches the current
time. For example, ``30 4 1,15 * 5'' would cause a command to be run at
4:30 am on the 1st and 15th of each month, plus every Friday.

dinakumar12 · 04-18-2011, 08:58 AM

Hi michaelk,

Thanks for your reply.

``30 4 1,15 * 5'' from your example.

The command should run only when the date 1st and 15th of the month comes on friday. Is that possible.

michaelk · 04-18-2011, 09:27 AM

FYI that was a quote from the man pages...
If you want to run a job on a particular day / day of the week then you need something like the following.

04 07 1,15 * * [ "$(date '+\%a')" == "Fri" ] && /path/to/your/job.sh

dinakumar12 · 04-19-2011, 07:13 AM

Thanks michaelk,

it works

I used

04 07 1,15 04 * [ "$(date '+\%w')" == "5" ] && /path/to/your/job.sh

This in cron to execute my job only on 1st and 15th date of April and that too only when it falls on friday.