Scheduling jobs using at command

[PM Srividhya]

Hi all,

I have a list of scripts to be run on batch and I have a menu to start/stop them.

For e.g. On executing the menu_script, it displayes as following:
******************************
List of batches

1. script 1
2. script 2
3. script 3
.
.
10. stop batch jobs

99. exit
Enter option:
***********************************

On entering the option I want to put the script in the scheduler(run the script at some time interval - . ./script | at "now + 30 minutes").
This makes the script to run after 30 minutes, but it is not repating again.
I will be passing arguments from the menu_script to script1 and so I cannot give
echo ". $0" | at "" as the last statement in the script1 (as mentioned in the man page!)

How do I repeat run the script using at command? I don't want to use crontab.

Thanks,
Vidhya.

P.S. This time I'll be very generous in giving points ;O)

[Peter Godron]

Hi,
you could include in your script1/script2.. files the at command, which would then trigger the repeat run.

Problem is, if the system is shut down, you will lose your at jobs, that is why cron was invented.

[Dennis Handly]

>so I cannot give echo ". $0" | at "" as the last statement in the script1 (as mentioned in the man page!)
>How do I repeat run the script using at command?

If you can't edit the script, you can't repeat them. That is where you need to add the "at now + 30".

I suppose you could pass a parm -r ## to your script that tells it to optionally reschedule itself using at(1).

[SANTOSH S. MHASKAR]

Hi,

How do u want to repeat it?

After certain interval OR after finishing running instance of script?

-Santosh

[PM Srividhya]

I want to repeat it after regular intervals.

[Pete Randall]

As Peter tried to explain, you need to put something like this in your script:

echo "/script1" | at now + 30 minutes

That way, every time the script is run, it tells at to do it again in 30 minutes.


Pete

[SANTOSH S. MHASKAR]

Hi,

U can do like this,


create a file say JOB_PARAM

Enter following to it.
---------------------------
#! /usr/bin/ksh
JOB_REPEAT=TRUE

# Repeat interval in seconds
REPEAT_INTERVAL=1800 # 30 mins
--------------------------------

At the beginning of ur script add following
-------------------------------------------
. /JOB_PARAM

while [ JOB_REPEAT="TRUE" ]
do
at -f
sleep REPEAT_INTERVAL
done
-----------------------------------------


Thats all.


If u want to stop the job set


JOB_REPEAT=FALSE in JOB_PARAM

If u want to change repeat interval
change REPEAT_INTERVAL value in JOB_PARAM.


-Santosh

[Yogeeraj_1]

hi,

below a quote from "man at" which clear explains how to achieve this:

Add a command to the file named weekly-run in directory jobs in the home directory so that it automatically reschedules itself every time it runs. This example reschedules itself every Thursday at 1900 (7:00 p.m.):

echo "sh $HOME/jobs/weekly-run" | at 1900 thursday next week


hope this helps!

kind regards
yogeeraj

[Dennis Handly]

>echo "sh $HOME/jobs/weekly-run" | at ...

I assume the reason for the silly echo instead of doing "at -f file", is to allow changes to the file between "now" and that future date?

[PM Srividhya]

I think I have mentioned that I have to pass some arguments to the script from the calling script and so I cannot use it the way mentioned in the man page.

**I will be passing arguments from the menu_script to script1 and so I cannot give
echo ". $0" | at "" as the last statement in the script1 (as mentioned in the man page!)**

[SANTOSH S. MHASKAR]

U can write in while loop as

sh |at now +
in place of
at -f

try this


-Santosh

[Dennis Handly]

>**I will be passing arguments from the menu_script to script1 and so I cannot give
echo ". $0" | at "" as the last statement in the script1 (as mentioned in the man page!)**

Can you or can't you edit script1?? Passing args to script1 has nothing to do with editing it.

[Dennis Handly]

You can of course have script1 pass its current parms back to itself when it invokes at(1).