Can one .PHP file edit another?

Question

So I have a file for constants. I want to let user define them and then edit my .php filr with that global constants (not xml - real PHP file )

With such code for exampl

Answer 1

Your can write program that edit any file including php file.

BTW. Be carefull! If you show your program how to modify itself it may do it over and over very fast, and finally start killing people like in matrix or terminator movies...