Cron Jobs Run At The Same Time

Question

In my cron job file I have two cronjobs defined:

#Yo1 MAILTO="[email protected]"
*1****wget -O - -q "http://example.com/cron/test1.php">/dev/null 2>&1
#Yo1 MAILTO="[email protected]"
*15****wget -O - -q "http://example.com/cron/test2.php">/dev/null 2>&1
The PHP files are simple just sending mails with different subjects.

The issue is that both cronjobs are running on the same time every minute, but as you can see I want them to run on different times. First - every minute, second - every 15 minutes.

Can you help me with this. I can't figure out whats wrong.

Answer 1

According to manpage of crontab(5), you could specify lists (0,15,30,45) or steps (*/15).

So, you could use the following crontab entries :

#Yo1 MAILTO="[email protected]"
* 1 * * * * wget -O - -q "http://example.com/cron/test1.php">/dev/null 2>&1

#Yo1 MAILTO="[email protected]"
*/15 * * * * wget -O - -q "http://example.com/cron/test2.php">/dev/null 2>&1

Prefer 0,15,30,45 for portability instead of */15 * * * *.

Answer 2

Cron only allows for a minimum of one minute. What you could do is write a shell script with an infinite loop that runs your task, and then sleeps for 1 seconds. That way your task would be run more or less every 1 seconds, depending on how long the task itself takes.