Running php or bash script in dialplan

[mdriaz]

I am in the local_extension dialplan, i wanted to run a script when any incoming call, however i am unable to execute anything.

tried many things like
action set result=${system(`/bin/echo 'System API Test'`)}
action set result=${usr/bin/php /path/bash.php}

 

[mdriaz]

and i want to run the script on every extension call, no matter call come from ring group, ext to ext or from call center module, if an invite is send to an extension, i want to execute a script, which dialplan should i target?