Cron : Setting alternative seconds

Question

I posted a question the other day about setting alternative minutes in cron, and i was given a lovely simple answer.

0-59/2 * * * * first_script
1-59/2 * * * * second_script

This worked brilliantly, however i have seen realized that i need my scripts to run quicker than every minute.

I know cron doesn't support seconds, but you can bluff it by using sleep, like so

* * * * * /foo/bar/your_script
* * * * * sleep 15; /foo/bar/your_script
* * * * * sleep 30; /foo/bar/your_script
* * * * * sleep 45; /foo/bar/your_script

So i need to combine the both of these so that i can get them to run alternatively every 15 seconds for instance.

Any ideas?

can you make it so that the sleep intervals are *15 30 15 30...*? — cctan, Apr 02 '12 at 10:26
And disregard the alternative minutes thing altogether? Sounds like that might work — cosmicsafari, Apr 02 '12 at 10:44

score 2 · Accepted Answer · answered Feb 13 '13 at 09:27

2

Ended up with the following code to get my scripts to run in shorter intervals than 1 minute.

* * * * * /usr/bin/php -q /path/to/file/script1.php
* * * * * sleep 15; /usr/bin/php -q /path/to/file/script2.php
* * * * * sleep 30; /usr/bin/php -q /path/to/file/script1.php
* * * * * sleep 45; /usr/bin/php -q /path/to/file/script2.php

answered Feb 13 '13 at 09:27

cosmicsafari

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You can use that with `run-one` or flock to ensure that only single instance of script will be run at a time – Artem Bernatskyi Nov 07 '20 at 14:11

Cron : Setting alternative seconds

1 Answers1