$re = ';(?<prefix1>\d{0,3}?)(?<suffix1>\d{1,3})\/(?<prefix2>\d{0,3}?)(?<suffix2>\d{1,3})\/;';
$str = '1/1/
12/1/
123/1/
1234/1/
12345/1/
123456/1/
1/12/
1/123/
1/1234/
1/12345/
1/123456/
12/12/
123/12/
1234/12/
12345/12/
123456/12/
12/123/
12/1234/
12/12345/
12/123456/
123/123/
1234/123/
12345/123/
123456/123/
123/1234/
123/12345/
123/123456/
1234/1234/
12345/1234/
123456/1234/
1234/12345/
1234/123456/
12345/12345/
123456/12345/
12345/123456/
123456/123456/
';
preg_match_all($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