URL regex - not getting it to work

Question

I am using the following regex to find if there is a url present in a text, however it seems to miss some URLs like:

youtube.be/8P0BxJO
youtube.com/watch?v=VrmlFL

and also some bit.ly links (but not all)

Match m = Regex.Match(nc[i].InnerText, 
   @"(http(s)?://)?([\w-]+\.)+[\w-]+(/\S\w[\w- ;,./?%&=]\S*)?");

if (m.Success)
{
    MessageBox.Show(nc[i].InnerText);
}

any ideas how to fix it?

Your regex returns true for your examples; your issue lies elsewhere. — Rawling, May 17 '12 at 14:04
Perhaps you can supply us with more details about your code and the text you are trying to parse. — Rich McCollister, May 17 '12 at 14:08
As other comments suggest, both URLs work with the current expression, as tested with this little handy tool over at http://gskinner.com/RegExr/ — Richard, May 17 '12 at 14:25
Your regex works for me, but I think you are missing a backslash before "?" — Ondra, May 17 '12 at 15:12
@Ondra - ? isn't a special character inside a character class. — Rawling, May 17 '12 at 15:16
It matches fine as it is. Though, it also matches `bad.so` in the sentence `this is bad.so not good` :) — Ja͢ck, May 18 '12 at 03:12

score 0 · Answer 1 · edited May 23 '17 at 12:27

See this related question, the first answer should help you out. The suggestion both finds links and then replaces them, so obviously just take what you need. This and this article are different approaches that should get you more or less the same result.

Another (perhaps more reliable) non-regex approach would be to tokenize the string by splitting on spaces and punctuation, and then checking the tokens to see whether they are a valid uri using Uri.IsWellFormedUriString (which only works on well formed uri's, as this question points out).

URL regex - not getting it to work

1 Answers1