tcpipSocket/Echo/Client/Client.cs

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

namespace Client;

internal class Client
{
	static void Main(string[] args)
	{
		using (Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp))
		{
			IPEndPoint endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 20000);
			socket.Connect(endPoint);

			while (true)
			{
				string str = Console.ReadLine() ?? string.Empty;
				if (str == "exit")
					return;

				byte[] buffer = Encoding.UTF8.GetBytes(str);
				byte[] newBuffer = new byte[2 + buffer.Length];
				byte[] dataSize = BitConverter.GetBytes(IPAddress.HostToNetworkOrder((short)buffer.Length));

				Array.Copy(dataSize, 0, newBuffer, 0, dataSize.Length);
				Array.Copy(buffer, 0, newBuffer, 2, buffer.Length);
				socket.Send(newBuffer);

				byte[] headerBuffer = new byte[2];
				int headerReceive = socket.Receive(headerBuffer);
				if (headerReceive < 1)
				{
					Console.WriteLine("Disconnecting client...");
					return;
				}
				else if (headerReceive == 1)
				{
					socket.Receive(headerBuffer, 1, 1, SocketFlags.None);
				}

				short totalDataSize = IPAddress.NetworkToHostOrder(BitConverter.ToInt16(headerBuffer));
				byte[] dataBuffer = new byte[totalDataSize];
				int dataReceived = 0;
				while (dataReceived < totalDataSize)
				{
					int n = socket.Receive(dataBuffer, dataReceived, totalDataSize - dataReceived, SocketFlags.None);
					dataReceived += n;
				}

				string receivedMessage = Encoding.UTF8.GetString(dataBuffer);
				Console.WriteLine($"[Received] {receivedMessage}");

				//byte[] buffer2 = new byte[256];
				//int byteRead = socket.Receive(buffer2);
				//if (byteRead < 1)
				//{
				//	Console.WriteLine("Disconnecting server...");
				//	return;
				//}

				//string str2 = Encoding.UTF8.GetString(buffer2);
				//Console.WriteLine($"[Receive] {str2}");
			}
		}
	}
}