다시 써보는 에코서버 window 버전

#include <iostream>
#include <winsock2.h>
#include <WS2tcpip.h>
#include <array>

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

int main() {
    WSADATA wsaData;
    if (::WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        std::cerr << "WSAStartup failed." << std::endl;
        return 1;
    }

    SOCKET listenSocket = ::socket(AF_INET, SOCK_STREAM, 0);
    if (listenSocket == INVALID_SOCKET) {
        std::cerr << "Failed to create socket." << std::endl;
        ::WSACleanup();
        return 1;
    }

    constexpr uint16_t port = 8888;
    SOCKADDR_IN serverAddress{
        .sin_family = AF_INET,
        .sin_port = htons(port),
        .sin_addr{.S_un{.S_addr = htonl(INADDR_ANY)}},
    };

    if (::bind(listenSocket, reinterpret_cast<SOCKADDR*>(&serverAddress), sizeof(serverAddress)) == SOCKET_ERROR) {
        std::cerr << "Bind failed." << std::endl;
        ::closesocket(listenSocket);
        ::WSACleanup();
        return 1;
    }

    if (::listen(listenSocket, SOMAXCONN) == SOCKET_ERROR) {
        std::cerr << "Listen failed." << std::endl;
        ::closesocket(listenSocket);
        ::WSACleanup();
        return 1;
    }

    SOCKET clientSocket;
    SOCKADDR_IN clientAddress;
    int clientAddressSize = sizeof(clientAddress);

    while ((clientSocket = ::accept(listenSocket, reinterpret_cast<SOCKADDR*>(&clientAddress), &clientAddressSize)) != INVALID_SOCKET) {
        std::cout << "새 클라이언트가 연결되었습니다." << std::endl;

        int receiveSize;
        std::array<char, 128> receivedBuffer;

        while ((receiveSize = ::recv(clientSocket, receivedBuffer.data(), receivedBuffer.size(), 0)) > 0) {
            ::send(clientSocket, receivedBuffer.data(), receiveSize, 0);
            std::cout.write(receivedBuffer.data(), receiveSize);
            std::cout << std::endl;
            receivedBuffer.fill(0);
        }

        if (receiveSize == SOCKET_ERROR) {
            std::cerr << "Receive failed." << std::endl;
        }

        ::closesocket(clientSocket);
        std::cout << "클라이언트가 연결이 끊겼습니다." << std::endl;
    }

    if (clientSocket == INVALID_SOCKET) {
        std::cerr << "Accept failed." << std::endl;
    }

    ::closesocket(listenSocket);
    ::WSACleanup();
    return 0;
}