How to run cron in seconds

I got cron to run at 10,20,30,40 and 50 minutes.
10,20,30,40,50 * * * *

but how to make cron run at 10 and lets say 15 seconds, and so on ?

 

Minimum limit is every 1 minute.

However, you can simulate with php by using the sleep command:

sleep(5); to sleep 5 seconds and then do the next action.

 

same can be done from bash also. run a shell script in background with help of cron and use sleep command to run it say every 2seconds

 

Yes cron starts from mins its better to use sleep as the above person said

 

Exept you have a dedicated server, I don't recommend you to run cron job every seconds.
It may cause high server load.