// i want a changed $ReElements so $str2 is parsed just as $str

$ReElements = '/<(\w+)\s*([^\/>]*)\s*(?:\/>|>(.*?)<(\/\s*\1\s*)>)/s';
$str = '<test atr="test" atr2="test2" />';
$str2 = '<test atr="test/" atr2="test2" />';
preg_match_all ($ReElements, $str, $matches);
preg_match_all ($ReElements, $str2, $matches2);
echo "<pre>";
print_r($matches);
print_r($matches2);