online_security_project/client/Program.cs

using System;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;

namespace Client;

public class Program
{
    static void Main(string[] args)
    {
        using TcpClient client = new("127.0.0.1", 12345);

        byte[] toSend = Encoding.ASCII.GetBytes("hello server");
        
        var stream = client.GetStream();

        var inputTask = Task.Run(async () => await HandleUserInput(client, stream));
        var serverInput = Task.Run(async () => await HandleServerInput(client, stream));

        _ = Task.WaitAny(inputTask, serverInput);
        
    }
 
    static async Task HandleUserInput(TcpClient client, NetworkStream stream) {
        while(client.Connected) {
            string? input = Console.ReadLine();
            if(input == null) {
                await Task.Delay(100);
                continue;
            }
            else {
                stream.Write(Encoding.ASCII.GetBytes(input));
                Console.WriteLine($"[{DateTime.Now}]Sent to server: {input}");
            }
        }
    }

    static async Task HandleServerInput(TcpClient client, NetworkStream stream) {
        byte[] buffer = new byte[1024];
        while(client.Connected) {
            int readLen = await stream.ReadAsync(buffer);
            if(readLen != 0) {
                string fromServer = Encoding.ASCII.GetString(buffer[..readLen]);
                Console.WriteLine($"[{DateTime.Now}]\t\tFrom server: {fromServer}");

            }
        }
    }
}