Question

Why the location is not listed on the response Headers?

My code:

        string url = "http://hehe.freevar.com/files.php";
        HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
        req.Method = "HEAD";
        Console.WriteLine(req.GetResponse().Headers);

Answer 1

From Wikipedia:

The HTTP Location header is returned
in responses from an HTTP server under
two circumstances:

1. To force a web browser to load a different web page. It is passed as
   part of the response by a web server
   when the requested URI has:

   • Moved temporarily, or
   • Moved permanently

The HttpWebRequest class has a property AllowAutoRedirect which defaults to true:

Set AllowAutoRedirect to true if you
want the request to automatically
follow HTTP redirection headers to the
new location of the resource.

This means you will never see the redirect request unless you set AllowAutoRedirect to false before making the request:

string url = "http://hehe.freevar.com/files.php";
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
req.AllowAutoRedirect = false;
req.Method = "HEAD";
Console.WriteLine(req.GetResponse().Headers);

Then you get the following response which does include Location:

Keep-Alive: timeout=1, max=10000
Connection: Keep-Alive
Content-Type: text/html
Date: Wed, 01 Jun 2011 01:32:18 GMT
Location: http://www.160by2.com/post-registration.aspx
Server: Apache
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