Enable Exec()

How can i enable php exec() ?

I looked for disable_functions=, but there is nothing is arranged for this i mean it is blank. like this : "disable-functions ="

I thought if i removed "exec()" from there, then i would enable it. But even though there is no "exec" commond in disable functions, i cant run a file.

exec is the dangerous PHP function

may i know which version of php you're using and how you installed the php version or it is cwp's default ?