Get Root Directory Path of a PHP project

use the PHP function:

getcwd()

Gets the current working directory.

For PHP >= 5.3.0 try

PHP magic constants.

__DIR__

And make your path relative.

For PHP < 5.3.0 try

dirname(__FILE__)

When you say that

$_SERVER['DOCUMENT_ROOT']

contains this path:

D:/workspace

Then D: is what you are looking for, isn't it? In that case you could explode the string by slashes and return the first one:

$pathInPieces = explode('/', $_SERVER['DOCUMENT_ROOT']);
echo $pathInPieces[0];

This will output the server's root directory.

Update: When you use the constant DIRECTORY_SEPARATOR instead of the hardcoded slash ('/') this code is also working under Windows.

Update 2: The $_SERVER global variable is not always available. On command line (cli) for example. So you should use __DIR__ instead of $_SERVER['DOCUMENT_ROOT']. __DIR__ returns the path of the php file itself.