C++ socket 实现服务端与客户端互相通信

参考博客：https://blog.csdn.net/axiqia/article/details/52454581
https://blog.csdn.net/u012391923/article/details/52881938

// Server.cpp : Defines the entry point for the console application.
//

#include "winsock2.h"
#pragma comment(lib, "ws2_32.lib")
#include <iostream>
using namespace std;
int main(int argc, char* argv[])
{
    const int BUF_SIZE = 64;
    WSADATA         wsd;            //WSADATA变量
    SOCKET          sServer;        //服务器套接字
    SOCKET          sClient;        //客户端套接字
    SOCKADDR_IN     addrServ;;      //服务器地址
    char            buf[BUF_SIZE];  //接收数据缓冲区
    char            sendBuf[BUF_SIZE];//返回给客户端得数据
    int             retVal;         //返回值
                                    //初始化套结字动态库
    if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0)
    {
        cout << "WSAStartup failed!" << endl;
        return 1;
    }

    //创建套接字
    sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (INVALID_SOCKET == sServer)
    {
        cout << "socket failed!" << endl;
        WSACleanup();//释放套接字资源;
        return  -1;
    }

    //服务器套接字地址 
    addrServ.sin_family = AF_INET;
    addrServ.sin_port = htons(4999);
    addrServ.sin_addr.s_addr = INADDR_ANY;
    //绑定套接字
    retVal = bind(sServer, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN));
    if (SOCKET_ERROR == retVal)
    {
        cout << "bind failed!" << endl;
        closesocket(sServer);   //关闭套接字
        WSACleanup();           //释放套接字资源;
        return -1;
    }

    //开始监听 
    retVal = listen(sServer, 1);
    if (SOCKET_ERROR == retVal)
    {
        cout << "listen failed!" << endl;
        closesocket(sServer);   //关闭套接字
        WSACleanup();           //释放套接字资源;
        return -1;
    }

    //接受客户端请求
    sockaddr_in addrClient;
    int addrClientlen = sizeof(addrClient);
    sClient = accept(sServer, (sockaddr FAR*)&addrClient, &addrClientlen);
    if (INVALID_SOCKET == sClient)
    {
        cout << "accept failed!" << endl;
        closesocket(sServer);   //关闭套接字
        WSACleanup();           //释放套接字资源;
        return -1;
    }

    while (true)
    {
        //接收客户端数据
        ZeroMemory(buf, BUF_SIZE);
        retVal = recv(sClient, buf, BUF_SIZE, 0);
        if (SOCKET_ERROR == retVal)
        {
            cout << "recv failed!" << endl;
            closesocket(sServer);   //关闭套接字
            closesocket(sClient);   //关闭套接字     
            WSACleanup();           //释放套接字资源;
            return -1;
        }
        if (buf[0] == '0')
            break;
        cout << "客户端发送的数据: " << buf << endl;

        cout << "向客户端发送数据: ";
        cin >> sendBuf;

        send(sClient, sendBuf, strlen(sendBuf), 0);
    }

    //退出
    closesocket(sServer);   //关闭套接字
    closesocket(sClient);   //关闭套接字
    WSACleanup();           //释放套接字资源;

    return 0;
}

#include "winsock2.h"
#include <iostream>
#pragma comment(lib, "ws2_32.lib")
#pragma warning(disable:4996) //必须加上
using namespace std;
BOOL RecvLine(SOCKET s, char* buf); //读取一行数据

int main(int argc, char* argv[])
{
    const int BUF_SIZE = 64;

    WSADATA wsd; //WSADATA变量
    SOCKET sHost; //服务器套接字
    SOCKADDR_IN servAddr; //服务器地址
    char buf[BUF_SIZE]; //接收数据缓冲区
    char bufRecv[BUF_SIZE];
    int retVal; //返回值
                //初始化套结字动态库
    if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0)
    {
        cout << "WSAStartup failed!" << endl;
        return -1;
    }
    //创建套接字
    sHost = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (INVALID_SOCKET == sHost)
    {
        cout << "socket failed!" << endl;
        WSACleanup();//释放套接字资源
        return  -1;
    }

    //设置服务器地址
    servAddr.sin_family = AF_INET;
    servAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    servAddr.sin_port = htons((short)4999);
    int nServAddlen = sizeof(servAddr);

    //连接服务器
    retVal = connect(sHost, (LPSOCKADDR)&servAddr, sizeof(servAddr));
    if (SOCKET_ERROR == retVal)
    {
        cout << "connect failed!" << endl;
        closesocket(sHost); //关闭套接字
        WSACleanup(); //释放套接字资源
        return -1;
    }
    while (true)
    {
        //向服务器发送数据
        ZeroMemory(buf, BUF_SIZE);
        cout << " 向服务器发送数据:  ";
        cin >> buf;
        retVal = send(sHost, buf, strlen(buf), 0);
        if (SOCKET_ERROR == retVal)
        {
            cout << "send failed!" << endl;
            closesocket(sHost); //关闭套接字
            WSACleanup(); //释放套接字资源
            return -1;
        }
        //RecvLine(sHost, bufRecv);
        ZeroMemory(bufRecv, BUF_SIZE);
        recv(sHost, bufRecv, BUF_SIZE, 0); // 接收服务器端的数据， 只接收5个字符
        cout << endl << "从服务器接收数据：" << bufRecv;
        cout << "\n";
    }
    //退出
    closesocket(sHost); //关闭套接字
    WSACleanup(); //释放套接字资源
    return 0;
}