$re = '/(\d{1,})\s\//m';
$str = '- 1 / something / something else / ...
~ 2 / another something / something else / ... / ...
- 3-4 / thing / ...
-~ 5-6 / ... / ... / ... / ... / ...';
preg_match_all($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