resolve-http-redirects.js

/* For Node.js - resolve a chain of HTTP redirects
   Uses getResponse() from http://gist.github.com/399276
   Example: resolveHttpRedirects('http://ow.ly/1Kn4j', function(url) { sys.puts(url) });
*/

function resolveHttpRedirects(url, callback, maxnum) {
    maxnum = maxnum || 3;
    var count = 0;
    function next(url) {
        getResponse(url, function(response) {
            if (response.statusCode == 301 || response.statusCode == 302) {
                if (count >= maxnum) {
                    callback(response.headers.location);
                } else {
                    count += 1;
                    next(response.headers.location);
                }
            } else {
                callback(url);
            }
        })
    }
    next(url);
}