$re = '/^([a-z]+)-((?:(?:0|[1-9](?:[0-9]+)?)\.){2}(?:0|[1-9](?:[0-9]+)?))$/m';
$str = 'package-0.0.1
package-0.1.1
package-1.0.1
package-0.10.1
package-0.01.1
package-01.0.1
package-0.0.01';
preg_match_all($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