$re = '/^(?:(?!Windows Phone).)*(iPhone|iPad|iPod)/i';
$str = 'Mozilla/5.0 like (Mobile; Windows Phone 8.1; Android 4.0; ARM; Trident/7.0 Touch; rv:11.0; IEMobile/11.0; NOKIA; Lumia 925) iPhone OS 7_0_3 Mac OS X AppleWebkit/537 (KHTML, like Gecko) Mobile Safari/537';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php