CODEWITHSUNDEEP
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Harnish
Harnish

Reputation: 891

Running a cron job randomly for every one hour

I want a cronjob to run every one hour randomly. (i.e if the first job runs at 58 minutes,the second job should run at 47 minutes and the third one at 52 minutes and so on) But this should run randomly for everyone hour. Is there a way to do this?

Upvotes: 5

Views: 8349

Answers (2)

Mark Setchell
Mark Setchell

Reputation: 207445

You could run a job every hour, on the hour, that sleeps up to 3,599 seconds and then executes your script:

0 * * * * /bin/bash -c 'sleep $((RANDOM%3600))' && /path/to/yourScript

Or, with Perl:

0 * * * * /path/to/perl -e 'sleep int rand 3600' && /path/to/yourScript

Or, using PHP if you prefer that to Perl:

0 * * * * /path/to/php -r 'sleep(rand(0,3599));' && /path/to/yourScript

You can find the path to Perl with:

which perl

likewise for PHP:

which php

Upvotes: 8

likewhoa
likewhoa

Reputation: 123

Instead of using perl or even php, just use the BASH $RANDOM built in divided by 3600 which equals one hour like so.

0 * * * * sleep $((RANDOM%3600)) && /path/to/yourScript

Keep in mind that you will probably have some race conditions with a script sleeps randomly close to an hour depending on how long it takes for your script to execute.

Upvotes: 6

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