Detect the user's home dir on Linux/Windows

gistfile1.php

<?php

/**
 * Get the home directory
 * 
 * @see http://techblog.zabuchy.net/2012/how-to-detect-user-home-directory-php-linux-windows/
 */
function homedir() {
  // getenv('HOME') isn't set on windows and generates a Notice.
  $home = getenv('HOME');
  if (empty($home)) {
    if (!empty($_SERVER['HOMEDRIVE']) && !empty($_SERVER['HOMEPATH'])) {
      // home on windows
      $home = $_SERVER['HOMEDRIVE'] . $_SERVER['HOMEPATH'];
    }
  }
  return empty($home) ? NULL : $home;
}