$re = '/data\/(.+)\/(.+)(?=\&)&?(.+)/';
$str = 'data/my.data/10&abc=10
data/my.data/10/&abc=10
data/my.data/10';
preg_match_all($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