c++

client.cpp

#include <iostream>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

int main() {

    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        cout << "WSAStartup failed\n";
        return 1;
    }

    SOCKET clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (clientSocket == INVALID_SOCKET) {
        cout << "Socket creation failed\n";
        WSACleanup();
        return 1;
    }

    sockaddr_in serverAddr;
    ZeroMemory(&serverAddr, sizeof(serverAddr));

    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(54000);

    inet_pton(AF_INET, "127.0.0.1", &serverAddr.sin_addr);

    if (connect(clientSocket, (sockaddr*)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR) {
        cout << "Connection failed. Error: " << WSAGetLastError() << endl;
        closesocket(clientSocket);
        WSACleanup();
        return 1;
    }

    cout << "Connected to server\n";

    int number;

    while (true) {

        cout << "Enter number: ";
        cin >> number;

        send(clientSocket, (char*)&number, sizeof(number), 0);

        int response;
        int bytes = recv(clientSocket, (char*)&response, sizeof(response), 0);

        if (bytes <= 0) {
            cout << "Server disconnected\n";
            break;
        }

        cout << "Server response: " << response << endl;
    }

    closesocket(clientSocket);
    WSACleanup();

    return 0;
}

server.cpp

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include <iostream>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib")

int main()
{
    WSADATA wsaData;

    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        std::cout << "WSAStartup failed\n";
        return 1;
    }

    SOCKET serverSocket = socket(AF_INET, SOCK_STREAM, 0);

    if (serverSocket == INVALID_SOCKET)
    {
        std::cout << "Socket creation failed\n";
        WSACleanup();
        return 1;
    }

    sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(54000);
    serverAddr.sin_addr.s_addr = INADDR_ANY;

    if (bind(serverSocket, (SOCKADDR*)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR)
    {
        std::cout << "Bind failed. Error: " << WSAGetLastError() << "\n";
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    if (listen(serverSocket, 1) == SOCKET_ERROR)
    {
        std::cout << "Listen failed\n";
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    std::cout << "Server started on port 54000\n";

    SOCKET clientSocket = accept(serverSocket, NULL, NULL);

    if (clientSocket == INVALID_SOCKET)
    {
        std::cout << "Accept failed\n";
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    std::cout << "Client connected\n";

    int number;

    while (true)
    {
        int bytesReceived = recv(clientSocket, (char*)&number, sizeof(number), 0);

        if (bytesReceived <= 0)
            break;

        int response = number + 1;
        send(clientSocket, (char*)&response, sizeof(response), 0);
    }

    closesocket(clientSocket);
    closesocket(serverSocket);
    WSACleanup();

    return 0;
}