Check if a user is using an iPhone, iPad, iPod or iPod touch

$userAgent = !empty($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : null;
$re = "/^(?:Mozilla\/5.0|QwantMobile\/2.0|Opera\/9.80) \((?:iPhone|iPhone (?:.){2}|iPad|iPod|iPod touch);/m";
preg_match($re, $userAgent, $iOsMatches);