Question

I am trying to find out a URL which belongs to :

http://domain.blob.core.windows.net/ 
https://domain.blob.core.windows.net/

http://domain.blob.core.windows.net
https://domain.blob.core.windows.net

The regex which I wrote

Regex reg2= new Regex(@"^http(s?)://[0-9a-zA-Z](.blob.core.windows.net)(/?)$");
string url = "http://abc.blob.core.windows.net";
        if(reg2.IsMatch(url))
        {
            Console.WriteLine("Yes");
        }
        else
        {
            Console.WriteLine("no");
        }

I am not able to find the match. It’s not working 🙁 I am pretty weak in regex. So can anyone help me to find out my mistake? I am using c#. It always prints no.

UPDATE : FINAL Answer which worked for me:

Regex reg2 = new Regex(@"^http(s?)\:\/\/[0-9a-zA-Z]*(\.blob\.core\.windows\.net)
(/?)$");

Just in case anybody needs something like this 🙂

Answer 1

You were close with "^http(s?)://[0-9a-zA-Z](.blob.core.windows.net)(/?)$" however [0-9a-zA-Z] should be [0-9a-zA-Z]+ as you want to be multiple characters before .blob.core.windows.net not just a single character.

Note: you don’t need brackets here if you not capturing parts of the match, the optional operator is applied to the previous character only so ^https?$ matches 'http' or 'https' and not '' as only the s is optional, Also escape all . characters as in regex the . characters matches any single character so to match a literal . you want \..

"^https?://[0-9a-zA-Z]+\.blob\.core\.windows\.net/?$"