For example here is some code.....
preg_match_all("/<a(?:[^>]*)href=\"([^\"]*)\"(?:[^>]*)>(?:[^<]*)<\/a>/is", $stripped_file, $matches);
What I don't get is all of those special characters? (?:[^>]*)
How can I do this with the h1 tag, h2 tag, and h3 tag?