Client

#define WIN32_LEAN_AND_MEAN
#include <iostream>
#include <string>
#include <windows.h>
#include <ws2tcpip.h>
#pragma comment(lib, "Ws2_32.lib")
#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"

using namespace std;
int main() {

    setlocale(0, "");

    cout << "Client starting...\n";

    WSADATA wsaData;
    WSAStartup(MAKEWORD(2, 2), &wsaData);

    addrinfo hints{};
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;

    addrinfo* result = nullptr;

    getaddrinfo("localhost", DEFAULT_PORT, &hints, &result);

    SOCKET connectSocket = socket(
        result->ai_family,
        result->ai_socktype,
        result->ai_protocol
    );

    connect(
        connectSocket,
        result->ai_addr,
        (int)result->ai_addrlen
    );

    freeaddrinfo(result);

    cout << "Connected to server!\n";

    while (true) {

        string message;

        cout << "\nEnter message (type exit to quit): ";
        getline(cin, message);

        if (message == "exit")
            break;

        send(
            connectSocket,
            message.c_str(),
            message.size(),
            0
        );

        char recvBuffer[DEFAULT_BUFLEN];

        int iResult = recv(
            connectSocket,
            recvBuffer,
            DEFAULT_BUFLEN - 1,
            0
        );

        if (iResult > 0) {

            recvBuffer[iResult] = '\0';

            cout << "Server reply: "
                << recvBuffer
                << endl;
        }
        else break;
    }

    shutdown(connectSocket, SD_SEND);
    closesocket(connectSocket);
    WSACleanup();

    cout << "Client shutting down.\n";

    return 0;
}

Server

#define WIN32_LEAN_AND_MEAN
#include <iostream>
#include <string>
#include <ctime>
#include <windows.h>
#include <ws2tcpip.h>
#pragma comment(lib, "Ws2_32.lib")
#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"

using namespace std;

string getCurrentTime() {

    time_t now = time(0);
    tm localTime;

    localtime_s(&localTime, &now);

    char buffer[10];

    sprintf_s(
        buffer,
        "%02d:%02d",
        localTime.tm_hour,
        localTime.tm_min
    );

    return string(buffer);
}

int main() {

    setlocale(0, "");

    cout << "Server starting...\n";

    WSADATA wsaData;
    WSAStartup(MAKEWORD(2, 2), &wsaData);

    addrinfo hints{};
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;
    hints.ai_flags = AI_PASSIVE;

    addrinfo* result = nullptr;

    getaddrinfo(NULL, DEFAULT_PORT, &hints, &result);

    SOCKET listenSocket = socket(
        result->ai_family,
        result->ai_socktype,
        result->ai_protocol
    );

    bind(listenSocket, result->ai_addr, (int)result->ai_addrlen);

    freeaddrinfo(result);

    listen(listenSocket, SOMAXCONN);

    cout << "Waiting for client connection...\n";

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

    closesocket(listenSocket);

    cout << "Client connected!\n";

    char recvBuffer[DEFAULT_BUFLEN];
    int iResult;

    do {

        iResult = recv(
            clientSocket,
            recvBuffer,
            DEFAULT_BUFLEN - 1,
            0
        );

        if (iResult > 0) {

            recvBuffer[iResult] = '\0';

            string message = recvBuffer;
            string reply;

            cout << "Client says: " << message << endl;

            if (message == "how are you")
                reply = "great!";
            else if (message == "what time is it")
                reply = getCurrentTime();
            else
                reply = "I don't understand";

            send(
                clientSocket,
                reply.c_str(),
                reply.size(),
                0
            );
        }

    } while (iResult > 0);

    shutdown(clientSocket, SD_SEND);
    closesocket(clientSocket);
    WSACleanup();

    cout << "Server shutting down.\n";

    return 0;
}