$re = '/^([+-]?)([0-9]+)?w?\s*?(0?[1-9]|[12][0-9]|3[01])?d?\s*?([01]?[0-9]?|2[0-3])?h?\s*?([0-5]?[0-9])?m?$/m';
$str = '-3w 4d 2h 1m
3w
4d
2h
1m
';
preg_match_all($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