C#

using System;
using System.IO;
using System.Net;
using System.Xml;
using Microsoft.Win32;
using System.Collections;
using System.Collections.Generic;
using System.Text;


namespace ConsoleApplication1
{
    class GDS
    {
        private string format = "&format=xml";
        public GDS()
        {
        }
        public ArrayList Search(string search, int num)
        {
            search = search.Replace(" ", "+");
            WebClient localGDS = new WebClient();
            string gdsResponse = null;
            try
            {
                StreamReader sr = new StreamReader(localGDS.OpenRead(getSearchQuery() + search + format + "&num=" + num.ToString()));
                gdsResponse = sr.ReadToEnd();
                sr.Close();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return null;
            }
            ArrayList ar = new ArrayList();

            if (gdsResponse != null)
            {
                XmlDocument xmlDoc = new XmlDocument();
                try
                {
                    xmlDoc.LoadXml(gdsResponse);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                    return null;
                }
                XmlNodeList resultsNode = xmlDoc.GetElementsByTagName("result");
                foreach (XmlNode result in resultsNode)
                {
                    XmlNodeList fields = result.ChildNodes;
                    Hashtable hash = new Hashtable();
                    foreach (XmlNode field in fields)
                    {

                        hash.Add(field.Name, field.InnerXml);
                    }
                    ar.Add(hash);
                }
            }
            return ar;
        }
        public ArrayList SearchOnlyFiles(string search, int num)
        {
            search = search.Replace(" ", "+");
            WebClient localGDS = new WebClient();
            string gdsResponse = null;
            try
            {
                StreamReader sr = new StreamReader(localGDS.OpenRead(getSearchQuery() + search + format + "&num=" + num.ToString() + "&flags=512"));
                gdsResponse = sr.ReadToEnd();
                sr.Close();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return null;
            }
            ArrayList ar = new ArrayList();

            if (gdsResponse != null)
            {
                XmlDocument xmlDoc = new XmlDocument();
                try
                {
                    xmlDoc.LoadXml(gdsResponse);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                    return null;
                }
                XmlNodeList resultsNode = xmlDoc.GetElementsByTagName("result");
                foreach (XmlNode result in resultsNode)
                {
                    XmlNodeList fields = result.ChildNodes;
                    Hashtable hash = new Hashtable();
                    foreach (XmlNode field in fields)
                    {

                        hash.Add(field.Name, field.InnerXml);
                    }
                    ar.Add(hash);
                }
            }
            return ar;
        }
        private string getSearchQuery()
        {
            RegistryKey currentUser = RegistryKey.OpenRemoteBaseKey(Microsoft.Win32.RegistryHive.CurrentUser, "");
            RegistryKey searchUrl = currentUser.OpenSubKey("Software\\Google\\Google Desktop\\API");
            object key = searchUrl.GetValue("search_url");
            return key.ToString();
        }
        [STAThread]
        static void Main(string[] args)
        {
            GDS gds = new GDS();
            string words = "java";
            ArrayList ar = gds.SearchOnlyFiles(words, 20);
            if (ar != null)
            {
                foreach (object o in ar)
                {
                    Hashtable hash = (Hashtable)o;
                    string category = (string)hash["category"];
                    if (category.Equals("file"))
                    {
                        Console.WriteLine("**********************************");
                        Console.WriteLine("File Found: " + (string)hash["url"]);
                    }
                }
            }
            Console.ReadLine();

        }
    }
}