client.txt

class Program
    {
    	static void Main(string[] args)
        {
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPEndPoint ep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 7000);
            s.Connect(ep);

            string key = string.Empty;
            byte[] buffer = new byte[1024];
            Console.WriteLine("connected...enter Q to exit");

            while((key = Console.ReadLine()) != "Q")
            {
                try
                {
                    byte[] msg = Encoding.UTF8.GetBytes(key);
                    s.Send(msg, SocketFlags.None);

                    int nbytes = s.Receive(buffer);
                    Console.WriteLine(Encoding.UTF8.GetString(buffer, 0, nbytes));
                }
                catch(SocketException e)
                {
                    Console.WriteLine(e.Message + e.ErrorCode);
                }
                catch(Exception e)
                {
                    Console.WriteLine(e.Message);
                }
            }
      
            s.Close();
        }
    }