Using "passthru" in a book page

I've been trying to get some network utilities to function through drupal. We are using drupal as an intranet site for our networking team. What I wanted to do was create a book page that does some basic network tests, the code works as a straight php page but the passthru function doesn't seem to return any values when called from inside a book page, firstly is this correct or have I made some other boo boo, secondly is it possible to get this to work. I figured it must not be allowing some commands for security purposes.

I have tried to post the code here but got an error. (suspicious input).