c++ 网络编程（一）TCP/IP 入门级客户端与服务端交互代码

#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <WinSock2.h>
#include <stdio.h>
#include <stdlib.h>

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

void main()
{
    WSADATA wsaData;
    int port = 5099;

    char buf[] = "Server: hello, I am a server.....";

    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        printf("Failed to load Winsock");
        return;
    }

    //创建用于监听的套接字
    SOCKET sockSrv = socket(AF_INET, SOCK_STREAM, 0);

    SOCKADDR_IN addrSrv;
    addrSrv.sin_family = AF_INET;
    addrSrv.sin_port = htons(port); //1024以上的端口号
    addrSrv.sin_addr.S_un.S_addr = htonl(INADDR_ANY);

    int retVal = bind(sockSrv, (LPSOCKADDR)&addrSrv, sizeof(SOCKADDR_IN));
    if (retVal == SOCKET_ERROR){
        printf("Failed bind:%d\n", WSAGetLastError());
        return;
    }

    if (listen(sockSrv, 10) == SOCKET_ERROR){
        printf("Listen failed:%d", WSAGetLastError());
        return;
    }

    SOCKADDR_IN addrClient;
    int len = sizeof(SOCKADDR);

    while (1)
    {
        //等待客户请求到来    
        SOCKET sockConn = accept(sockSrv, (SOCKADDR *)&addrClient, &len);
        if (sockConn == SOCKET_ERROR){
            printf("Accept failed:%d", WSAGetLastError());
            break;
        }

        printf("Accept client IP:[%s]\n", inet_ntoa(addrClient.sin_addr));

        //发送数据
        int iSend = send(sockConn, buf, sizeof(buf), 0);
        if (iSend == SOCKET_ERROR){
            printf("send failed");
            break;
        }

        char recvBuf[100];
        memset(recvBuf, 0, sizeof(recvBuf));
        //         //接收数据
        recv(sockConn, recvBuf, sizeof(recvBuf), 0);
        printf("%s\n", recvBuf);

        closesocket(sockConn);
    }

    closesocket(sockSrv);
    WSACleanup();
    system("pause");
}

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include <WinSock2.h>
#include <stdio.h>

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

void main()
{
    //加载套接字
    WSADATA wsaData;
    char buff[1024];
    memset(buff, 0, sizeof(buff));

    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        printf("Failed to load Winsock");
        return;
    }

    SOCKADDR_IN addrSrv;
    addrSrv.sin_family = AF_INET;
    addrSrv.sin_port = htons(5099);
    addrSrv.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");

    //创建套接字
    SOCKET sockClient = socket(AF_INET, SOCK_STREAM, 0);
    if (SOCKET_ERROR == sockClient){
        printf("Socket() error:%d", WSAGetLastError());
        return;
    }

    //向服务器发出连接请求
    if (connect(sockClient, (struct  sockaddr*)&addrSrv, sizeof(addrSrv)) == INVALID_SOCKET){
        printf("Connect failed:%d", WSAGetLastError());
        return;
    }
    else
    {
        //接收数据
        recv(sockClient, buff, sizeof(buff), 0);
        printf("%s\n", buff);
    }

    //发送数据
    char *buffSend = "hello, this is a Client....";
    send(sockClient, buffSend, strlen(buffSend) + 1, 0);
    printf("%d", strlen(buffSend) + 1);

    //关闭套接字
    closesocket(sockClient);
    WSACleanup();
    system("pause");
}