$re = '/^(?=[a-z0-9-]{32,36}$)[a-z0-9]+(?:-[a-z0-9]+)*$/m';
$str = 'd3bd55bf-062f-473b-9417-935f62c4c98a
d3bd55bf062f473b9417935f62c4c98a
d3bd-55bf062f473b9417935f62c4c98a
d3bd55-bf06-2f473b9417-935f62c4c98a';
preg_match_all($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