How to determine where a require request originated?

Is there any way to determine from within a required script, where that requir开发者_高级运维e call was made from?

So if Script B is required by Script A. How can I determine from within Script B that it is Script A who is making the request?

debug_backtrace might help you.

a $_SERVER['PHP_SELF'] in scripr B, will show the current file (script A)