Run controller function after every 30 seconds

[eluser]thefatladysingsopera[/eluser]
Hello,is there a way i can call a codeigniter controller after every 30 seconds?.

I can't use cron since its limited up to a minute.

Code:

*/1 * * * * /usr/bin/wget -O /dev/null http://example.com/index.php/cron/longPoll

[eluser]Narf[/eluser]

Code:

* * * * * <first run>; sleep 30; <second run>

You should however reconsider this, chances are it's a bad idea.