$re = '/([a-z-]+)\/([a-z]+[-]*[a-z]+)-([a-zA-Z0-9]+[-]*[a-z0-9]+)\/?$/m';
$str = 'class-s/ford-shelby-gt350r
class-s/exotic-rides-w70';
preg_match_all($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