Question

I started learning REGEX 2 days ago , now id like to make a small application that read the source code of a webpage and get webpages like http://page.com or http://www.page.com/sub/sub/sub?=value , etc….. , stuff like that , anyway that`s the code i typed :

Regex r = new Regex("http://\\w");

        HttpWebRequest httpwebrequest = (HttpWebRequest)WebRequest.Create("http://maktoob.yahoo.com/?p=us");
        HttpWebResponse response = (HttpWebResponse)httpwebrequest.GetResponse();

        StreamReader sr = new StreamReader(response.GetResponseStream());

        string line;

        while ((line = sr.ReadLine()) != null)
        {
            Match m = r.Match(line);
            if (m.Success)
            {
                Console.WriteLine("Match: " +m.Value);
            }
        }
        sr.Close();
        response.Close();

But the result is :

Match: http://l
Match: http://w
Match: http://x
Match: http://l
Match: http://q

It just get the first character after //
When i looked at my pattern i said lol yeah my pattern is http://\w , so it will get the first character , but i wanted to know what should i add to my pattern for it to get the rest of the link ????

Answer 1

If you only need to match hyperlinks within <a> elements, then you could take advantage of the enclosing quotes or double quotes to delimit your URL.

Regex regex = new Regex(@"(?<=href=('|""))https?://.*?(?=\1)");

That would match any text within an href='…' or href="…" attribute that starts with http:// or https://.