Example of simple HTTP client / server by using Socket

http.cs

using System;
using System.Net;
using System.Net.Sockets;

class Program
{
    static void Main(string[] args)
    {
        var s = new Socket(
            AddressFamily.InterNetwork,
            SocketType.Stream,
            ProtocolType.Tcp
        );

        var ip = Dns.Resolve("google.com").AddressList[0];
        s.Connect(new IPEndPoint(ip, 80));

        var req =
            $@"GET / HTTP/1.0
Host: google.com

";
        var buffer = System.Text.Encoding.ASCII.GetBytes(req);
        s.Send(buffer, 0, buffer.Length, SocketFlags.None);

        buffer = new byte[1024 * 4];
        s.Receive(buffer, 0, buffer.Length, SocketFlags.None);

        s.Shutdown(SocketShutdown.Receive);
        s.Close();

        var txt = System.Text.Encoding.ASCII.GetString(buffer);
        Console.WriteLine(txt);
    }

    static void Main2(string[] args)
    {
        var s = new Socket(
            AddressFamily.InterNetwork,
            SocketType.Stream,
            ProtocolType.Tcp
        );

        s.Bind(new IPEndPoint(
            IPAddress.Parse("127.0.0.1"), 8080));

        s.Listen(10);

        var i = 0;
        while (true)
        {
            i++;

            var client = s.Accept();

            var buffer = new byte[1024 * 4];
            client.Receive(buffer, 0, buffer.Length, SocketFlags.None);

            var response =
                $@"HTTP/1.0 200 OK
Content-Type: text/ascii
Content-Length: 17

Hello world! {i:0000}";
            buffer = System.Text.Encoding.ASCII.GetBytes(response);
            client.Send(buffer, 0, buffer.Length, SocketFlags.None);

            client.Shutdown(SocketShutdown.Send);
            client.Close();
        }
    }
}