Character escaping in regular expression

Question

I used this regex to match a hyperlink that contains a specific word in the href

<a( .*?)? href=\".*?" + word + ".*?\"( .*?)?>.*?</a>

This returns the first appearance of the matched link

Now i need to find all hyperlinks withthe same match, and I have tried this regex:

/<a [^>]*\bhref\s*=\s*"[^"]*word.*?<\/a>/

I'm having some problems making my compiler accept this expression. The problem seems to be escaping some special characters. It seems this part is a problem

"[^"]

I tried escaping the [ with \\, and putting @ in front of double quotes, but no luck.

The error reads "bad compile constant value".

Does anyone know how to format this regex to satisfy the compiler?

Answer 1

Regex is not a good way to parse HTML files..

You should use htmlagilitypack

HtmlWeb web = new HtmlWeb();
HtmlDocument doc = web.Load("http://yourWebSite.com");

List<String> hrefLst=doc.DocumentNode
                        .SelectNodes("//a[@href]")
                        .Select(x=>x.Attributes["href"].Value)
                        .Where(y=>y.Contains(word))
                        .ToList();

hrefLst now has all your required links.

Isn't that simple!

Answer 2

Although you can escape everything that needs to be escaped in the string, regular expressions are far easier to read when the string is @-quoted. The only thing you then need to worry about are double quotes, which need to be doubled.

string expression = @"/<a [^>]*\bhref\s*=\s*""[^""]*word.*?<\/a>/";

Note: As the comments say, this regex might fail. I haven't tested it, I just modified it to make it compile.