C++实现简单的tcp协议

Server.cpp

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

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

const int PORT = 8888;
const int BUFFER_SIZE = 1024;

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

    SOCKET serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket == INVALID_SOCKET) {
        std::cerr << "socket failed: " << WSAGetLastError() << std::endl;
        WSACleanup();
        return 1;
    }

    sockaddr_in serverAddress;
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.s_addr = INADDR_ANY;
    serverAddress.sin_port = htons(PORT);

    if (bind(serverSocket, reinterpret_cast<sockaddr*>(&serverAddress), sizeof(serverAddress)) == SOCKET_ERROR) {
        std::cerr << "bind failed: " << WSAGetLastError() << std::endl;
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

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

    std::cout << "Server listening on port " << PORT << std::endl;

    sockaddr_in clientAddress;
    int clientAddressSize = sizeof(clientAddress);
    SOCKET clientSocket = accept(serverSocket, reinterpret_cast<sockaddr*>(&clientAddress), &clientAddressSize);
    if (clientSocket == INVALID_SOCKET) {
        std::cerr << "accept failed: " << WSAGetLastError() << std::endl;
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    char buffer[BUFFER_SIZE];
    int bytesRead;
    while ((bytesRead = recv(clientSocket, buffer, BUFFER_SIZE, 0)) > 0) {
        buffer[bytesRead] = '\0';
        std::cout << "Received from client: " << buffer << std::endl;
        send(clientSocket, buffer, bytesRead, 0);
    }

    if (bytesRead == SOCKET_ERROR) {
        std::cerr << "recv failed: " << WSAGetLastError() << std::endl;
    }

    closesocket(clientSocket);
    closesocket(serverSocket);
    WSACleanup();
    system("pause");
    return 0;
}

 Client.cpp

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

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

const int PORT = 8888;
const int BUFFER_SIZE = 1024;

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

    SOCKET clientSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (clientSocket == INVALID_SOCKET) {
        std::cerr << "socket creation failed: " << WSAGetLastError() << std::endl;
        WSACleanup();
        return 1;
    }

    sockaddr_in serverAddress;
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_port = htons(PORT);
    inet_pton(AF_INET, "127.0.0.1", &serverAddress.sin_addr.s_addr);

    if (connect(clientSocket, reinterpret_cast<sockaddr*>(&serverAddress), sizeof(serverAddress)) == SOCKET_ERROR) {
        std::cerr << "connect failed: " << WSAGetLastError() << std::endl;
        closesocket(clientSocket);
        WSACleanup();
        return 1;
    }

    std::cout << "Connected to server." << std::endl;

    char message[] = "Hello from client!";
    send(clientSocket, message, strlen(message), 0);

    char buffer[BUFFER_SIZE];
    int bytesRead = recv(clientSocket, buffer, BUFFER_SIZE, 0);
    if (bytesRead > 0) {
        buffer[bytesRead] = '\0';
        std::cout << "Received from server: " << buffer << std::endl;
    }
    else {
        std::cerr << "recv failed: " << WSAGetLastError() << std::endl;
    }

    closesocket(clientSocket);
    WSACleanup();
    system("pause");
    return 0;
}

使用环境

大家可在vs中在同一解决方案下建立两个项目，先运行Server.cpp再运行Client.cpp即可。

有问题留言！