PHP DOCUMENT_ROOT in IIS (Windows servers)

If you've been searching for this page then you most certainly don't need me to explain anything, you just want the goodies. So here it is -just add the following code to the beginning of your PHP application and use $_SERVER['DOCUMENT_ROOT'] as you wish...


// let's make sure the $_SERVER['DOCUMENT_ROOT'] variable is set
if(!isset($_SERVER['DOCUMENT_ROOT'])){ if(isset($_SERVER['SCRIPT_FILENAME'])){
$_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr($_SERVER['SCRIPT_FILENAME'], 0, 0-strlen($_SERVER['PHP_SELF'])));
}; };
if(!isset($_SERVER['DOCUMENT_ROOT'])){ if(isset($_SERVER['PATH_TRANSLATED'])){
$_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr(str_replace('\\\\', '\\', $_SERVER['PATH_TRANSLATED']), 0, 0-strlen($_SERVER['PHP_SELF'])));
}; };
// $_SERVER['DOCUMENT_ROOT'] is now set - you can use it as usual...

And now, for those of you who want to know what this is all about:

Being an ASP developer, I am quite comfortable with the use of Server.MapPath. I can find the physical root of the website very easily like this...

Dim sRootOfWebsite
sRootOfWebsite = Server.MapPath("/")

...PHP on the other hand doesn't offer such a simple way of doing this, but it does supply a range of pre-defined run-time variables that make it development easy. Unfortunately, these are not so constant in PHP and depend on the server configuration. Many hosts purposely turn off certain variables for security reasons.

The most common example is the $_SERVER['DOCUMENT_ROOT'] variable, which is not available on IIS (Windows Servers). Which is what the code at the top of this article is all about.

For a proper explanation of the problem - and a much better read - see Finding the document root in PHP.