How to extract URL from a string which is not between certain characters?

Question

I want to extract all the URLs in a string that's not between two certain characters. It should not extract the URL if it is between the following characters:

" and "
"> and <

I have the following string:

Content <strong>http://www.helloworld.com/test</strong> with a hyperlink <a href="www.google.com">www.google.com</a> and also a normal link www.youtube.com dsdsd sometexthttp://www.website.com/test sdfsdfsdfg ssdgsdf sdfsdfsdf

Regex what I currently have is:

(http://|https://|ftp://|mailto:|www\.){1}(?![^>]*<)(?![^"]*")[^^\\\"\n\s\}\{\|\`<>~]*

It will extract:

www.youtube.com
http://www.website.com/test

It should also extract, but it doens't right now:

http://www.helloworld.com/test

It doesn't extract www.google.com (which is good)

https://regex101.com/r/UhVZWe/5

Rule 1, never use regex to parse HTML. Rule 2, if you need to parse HTML with regex see Rule 1 — freefaller, Oct 29 '19 at 13:35
I'd suggest parsing it with HtmlAgilityPack, and omit all `a` tags with their contents and then search within plain text nodes. — Wiktor Stribiżew, Oct 29 '19 at 13:51
The code was to be posted and explained but was marked duplicate which it's not. So, can only give you this which can't be shared with the community now, sorry. https://rextester.com/ISTLSJ20921 — , Oct 29 '19 at 19:41

score 0 · Answer 1 · answered Oct 29 '19 at 14:58

One of way of doing this would be to use the HTML Agility Pack.

Here is a sample piece of code that extracts all URLs from the inner text of all elements in your HTML fragment. You can modify it to extract only those you need:

var content = "<strong>http://www.helloworld.com/test</strong> with a hyperlink <a href=\"www.google.com\">www.google.com</a> and also a normal link www.youtube.com dsdsd sometext http://www.website.com/test sdfsdfsdfg ssdgsdf sdfsdfsdf";
HtmlAgilityPack.HtmlDocument document = new HtmlAgilityPack.HtmlDocument();
document.LoadHtml(content);                        
Regex regex = new Regex(@"(?:http(s)?:\/\/)?[\w.-]+(?:\.[\w\.-]+)+[\w\-\._~:/?#[\]@!\$&'\(\)\*\+,;=.]+", RegexOptions.Compiled);
FindMatchesInText(document.DocumentNode, regex);       

private void FindMatchesInText(HtmlNode parentNode, Regex regex)
{                        
    foreach (var node in parentNode.ChildNodes)
    {                
        var match = regex.Match(node.InnerText);
        while(match.Success)
        {
            Console.WriteLine(match.Value);
            match = match.NextMatch();
        }
        //Recurse
        FindMatchesInText(node, regex);
    }            
}

Output:

http://www.helloworld.com/test

http://www.helloworld.com/test

www.google.com

www.google.com

www.youtube.com

http://www.website.com/test

How to extract URL from a string which is not between certain characters?

1 Answers1