$re = '/(Linux;|iPhone;\s+CPU\s+iPhone)\s+(?<os_versione>\w+\s+\w+)/m';
$str = 'Android user - Mozilla/5.0 (Linux; Android 10; SAMSUNG SM-T590) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser / 12.1 Chrome/79.0.3945.136 Safari/537.36
Iphone user - Mozilla/5.0 (iPhone; CPU iPhone OS 14_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Mobile/15E148 Safari/604.1';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($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