正则表达式匹配Url，除了某个域

Question

I have the following regular expression that matches Url's. What I want to do is make it not match when a URL belongs to a certain domain, let's say google.com.

How can I do that? I've been reading other question and regular expression references and so far I could achieve it. My Regular expression:

^(https?:\/\/)?([\da-zA-Z\.-]+)\.([a-zA-Z\.]{2,6})([\/\w \.-]*)*\/?$

I use this to filter messages in a chat, I'm using C# to do so. Here's a tool in case you want to dig further: http://regexr.com/3faji

C# extension method:

static class String
{
    public static string ClearUrl(string text)
    {
        Regex regx = new Regex(@"^(https?:\/\/)?([\da-zA-Z\.-]+)\.([a-zA-Z\.]{2,6})([\/\w \.-]*)*\/?$",
        RegexOptions.IgnoreCase);
        string output = regx.Replace(text, "*");

        return output;

    }
}

Thanks for any help

Answer 1

You can use negative lookahead in your regex to avoid matching certain domains:

^(https?:\/\/)?(?!(?:www\.)?google\.com)([\da-zA-Z.-]+)\.([a‌​-zA-Z\.]{2,6})([\/\w .-]*)*\/?$

Or else:

^(https?:\/\/)?(?!.*google\.com)([\da-zA-Z.-]+)\.([a‌​-zA-Z\.]{2,6})([\/\w .-]*)*\/?$

(?!(?:www\\.)?google\\.com) is negative lookahead that will assert failure when we have www.google.com or google.com ahead.

RegEx Demo

Answer 2

这应该使用负向前瞻，并且还包括以www而不是协议开头的URL，也不是行的第一个字符：

((http|ftp|https):\/\/|www.)(?!google|www.google)[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#])?