How can I find an application's base url?

Question

I\'d like to find the base url of my application, so I can automatically reference other files in my application tree...

So given a file config.php in the base of my

Answer 1

If you want the path on the filesystem you can use $_SERVER['DOCUMENT_ROOT']
If you just want the path of the file that appears in the URL after the domain use $_SERVER['REQUEST_URI']