Please help about zend engine

hello sir/ma'am

So sory to bother you. My name is andre from Indonesia.
I'm sure you are busy, so please alow me to go straight to the point.
I'am working on my theses about PHP file encryption.
Perhaps it's kinda obsolete since there's Zend Optimizer, and Zend Guard

But i have problems, that i can't solve it my self within the remaining time.
So i decided to try to ask.

 If i not mistaken, PHP receive from apache server only the path of the
 requested file right?
 So if thats true, PHP(the engine) had a function to open that file right?

 So i need to find that function because i need to insert some code so when it read a file, it do some decryption first before go to further processing.

 I tried to find that function but i'm not sure. I found something on zend_ini_scanner.c and zend_language_scanner.c but i'm not
 realy sure about that.
 
 So can you please tell me what function or where i should insert my code?
 This is may be a noob question, but i really confused.

 I'm sory if my language is not polite, i realize my english not so good.
 I realy hope that you can help me sir/ma'am.
Thank you so much for your attention.

       
---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile.  Try it now.