PHP preg_match UUID v4

$uuid = 'http://domain.com/images/123/b85066fc-248f-4ea9-b13d-0858dbf4efc1_small.jpg';
preg_match('!/images/\d+/([a-z0-9\-]*)_!i', $uuid, $m);

And

preg_match('/[a-f0-9]{8}\-[a-f0-9]{4}\-4[a-f0-9]{3}\-(8|9|a|b)[a-f0-9]{3‌​}\-[a-f0-9]{12}/', $uuid, $m);

works too. Taken from here, but I don't know if we can rely on that.

You can try this simple pattern for uuids

preg_match('/\w{8}-\w{4}-\w{4}-\w{4}-\w{12}/',$uuid,$matches);