WinSock2.0通信的一个例子（基于VC++6.0开发测试）

实验目的：

掌握Winsock2.0套接字编程技术的基本方法。

实验要求：

运用TCP/IP Winsock2.0套接字编程技术，使用VC编写一个面向连接通信的服务端程序与客户端程序，服务器先与端口3000绑定，

然后等待客户连接，连接成功后就可与客户端互相收、发信息。交互中，通信任一方只要发送 bye, 通信过程便自动结束。

服务端：

#include <conio.h>
#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "Ws2_32.lib")

int main(int, char **)
{
    struct sockaddr addr;
    int recvLen, errCode;
    
    char msg[255] = {0};
    SOCKET sock, sersock;

    WORD wVersionRequested;
    WSADATA wsaData;
    LPSTR messageBuffer = NULL;

    SetConsoleTitle("服务端");

    wVersionRequested = MAKEWORD(2, 0);
    errCode = WSAStartup(wVersionRequested, &wsaData);

    if (errCode)
    { 
        printf("没有Windows Socket动态库!
");
        return WSAGetLastError();
    }

    if (LOBYTE(wsaData.wVersion) != 2 || //不是Winsock 2.0
        HIBYTE(wsaData.wVersion) != 0)
    {
        printf("需要Windows Socket 2!
");
        WSACleanup();
        return WSAGetLastError();
    }

    sock = socket(AF_INET, SOCK_STREAM, 0);


    if (sock == INVALID_SOCKET)
    { 
        printf("不能创建Socket!
");
        getch();
        WSACleanup(); 
        return 0;
    }

    ((sockaddr_in *)&addr)->sin_family = AF_INET;
    
    ((sockaddr_in *)&addr)->sin_port = htons(3000);

    ((sockaddr_in *)&addr)->sin_addr.s_addr = inet_addr("127.0.0.1");

    bind(sock, &addr, sizeof(addr));


    listen(sock, 1);


    printf("等待客户连接!
");
    recvLen = sizeof(addr);
    sersock = accept(sock, &addr, &recvLen);

    if (sersock == INVALID_SOCKET)
    {
        errCode = WSAGetLastError();

        size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER 
            | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
            NULL, errCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
            (LPSTR)&messageBuffer, 0, NULL);

        printf("%s
", messageBuffer);
        free(messageBuffer);
        
        getch();
        closesocket(sock);
        WSACleanup();
        return 0;
    }

    printf("有客户连接!
输入bye通信结束
");


    do
    {
        printf("
等待客户端输入信息......");
        recvLen = recv(sersock, msg, 200, 0);
        printf("
客户端:%s", msg);
    
        if (!strcmp(msg, "bye"))
            break;
        printf("
服务器:");
        gets(msg);
        
    
        send(sersock, msg, strlen(msg) + 1, 0);

    } while (strcmp(msg, "bye"));

    closesocket(sersock);
    closesocket(sock);
    printf("

会话结束，按任一键返回
");
    getch();
    WSACleanup();
    return 0;
}

客户端：

#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>

#pragma comment(lib, "Ws2_32.lib")

int main(int, char **)
{
    SOCKET sock;
    struct sockaddr addr;
    int errCode;
    char msg[255] = {0};

    WORD wVersionRequested;
    WSADATA wsaData;

    SetConsoleTitle("客户端");
    wVersionRequested = MAKEWORD(2, 0);
    errCode = WSAStartup(wVersionRequested, &wsaData);

    if (errCode)
    { 
        printf("没有Windows Socket动态库!
");
        return WSAGetLastError();
    }

    if (LOBYTE(wsaData.wVersion) != 2 || 
        HIBYTE(wsaData.wVersion) != 0)
    {
        printf("需要Windows Socket 2!
");
        WSACleanup(); 
        return WSAGetLastError();
    }

    sock = socket(AF_INET, SOCK_STREAM, 0);


    if (sock == INVALID_SOCKET)
    { 
        printf("不能创建Socket!
");
        getch();
        WSACleanup(); 
        return WSAGetLastError();
    }

    ((sockaddr_in *)&addr)->sin_family = AF_INET;

    ((sockaddr_in *)&addr)->sin_addr.s_addr = inet_addr("127.0.0.1");

    ((sockaddr_in *)&addr)->sin_port = htons(3000);

    printf("与服务器连接...!
");
    
    errCode = connect(sock, (sockaddr *)&addr, sizeof(addr));
    if (errCode == SOCKET_ERROR)
    { 
        printf("连接失败!
");
        getch();
        WSACleanup();
        return 0;
    }

    printf("成功连接到服务器127.0.0.1!
若输入bye则通信结束
");


    do
    {
        printf("

客户端:");
        gets(msg);
    
        send(sock, msg, strlen(msg) + 1, 0);

        if (!strcmp(msg, "bye")) break;

        printf("等待服务器响应......
");

        recv(sock, msg, 200, 0);

        printf("服务器:%s", msg);

    } while (strcmp(msg, "bye"));

    closesocket(sock);
    printf("
会话结束，按任一键返回
");
    getch();
    WSACleanup();
    return 0;
}

运行效果：

此为学校实验题目：word排版请用http://www.planetb.ca/syntax-highlight-word

Winsock2.0相关参考网站，拥有大量示例代码：https://www.tenouk.com/