This is StackOverflow after all. Your question is wrong. Your problem is wrong. You are wrong. I am right. Thread locked. Go read this other post that is totally unrelated to your problem I’ve decided isn’t the problem you’re facing because. I. Am. Right.
no, this is one of the worst answers on Stack Overflow
OP had a specific question to capture opening tags. The thing OP asked about can be done with regular expressions. It is true that arbitrarily nested languages like HTML cannot generally be parsed with regular expressions, but that is not what OP asked about.
save