Validate if the user agent belongs to a desktop client

isDesktopBrowser.php

function isDesktopBrowser(){
  if((strpos(strtolower($_SERVER["HTTP_USER_AGENT"]),"windows")!==false && strpos(strtolower($_SERVER["HTTP_USER_AGENT"]),"windows phone")===false) or (strpos(strtolower($_SERVER["HTTP_USER_AGENT"]),"linux")!==false && strpos(strtolower($_SERVER["HTTP_USER_AGENT"]),"android")===false) or strpos(strtolower($_SERVER["HTTP_USER_AGENT"]),"macintosh")!==false)
  {
    return true;
  }
  return false;
}