$re = '/^([1-6]|7[0-3]|74.0.3729.[0-1][0-2][0-9]$)/m';
$str = '74.0.3729.021
72
5
20
73
72
68.0.3440.106
73.0.3683.86
';
preg_match_all($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