Question

Is there a $_SERVER['DOCUMENT_ROOT'] equivalent which would work on both Apache and IIS without having to change configuration files? Or maybe some workarounds?

Answer 1

For IIS

if(empty($_SERVER['DOCUMENT_ROOT']) && !empty($_SERVER['SCRIPT_FILENAME'])) { 
  $_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr($_SERVER['SCRIPT_FILENAME'], 0, 0 - strlen($_SERVER['PHP_SELF'])));
} 
if(empty($_SERVER['DOCUMENT_ROOT']) && !empty($_SERVER['PATH_TRANSLATED'])) { 
  $_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr(str_replace('\\\\', '\\', $_SERVER['PATH_TRANSLATED']), 0, 0 - strlen($_SERVER['PHP_SELF'])));
}