基于TCP协议的”helloworld“

服务器端

#include "iostream"
#include "winsock2.h"
#pragma comment (lib, "ws2_32")

using namespace std;

int main()
{
    WSADATA wsaData;
    WSAStartup(MAKEWORD(2, 2), &wsaData);  //初始化ws2_32.dll动态库连接

    SOCKET s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);

    sockaddr_in sockaddr;
    sockaddr.sin_family = PF_INET;
    sockaddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1"); //IP地址，将IP转换为unsigned long型数值
    sockaddr.sin_port = htons(827); //端口号，本地字节顺序转换为网络字节顺序

    bind(s, (SOCKADDR*)&sockaddr, sizeof(SOCKADDR));

    listen(s, 1);

    SOCKADDR clientAddr;
    int nSize = sizeof(SOCKADDR);
    SOCKET clientSock;
    //从处于监听状态的流套接字的客户端请求队列中取出第一个请求，并创建一个新的套接字与客户端进行通信
    clientSock = accept(s, (SOCKADDR *)&clientAddr, &nSize); 

    send(clientSock, "hello client\n", strlen("hello client\n")+sizeof(char), 0);

    closesocket(clientSock);
    closesocket(s);

    WSACleanup();  //释放ws2_32.dll
    return 0;
}

客户端

#include "stdio.h"
#include "winsock2.h"
#pragma comment (lib, "ws2_32")

int main()
{
    WSADATA wsaData;
    WSAStartup(MAKEWORD(2, 2), &wsaData);

    SOCKET s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);

    sockaddr_in sockAddr;  //对服务器端的描述
    sockAddr.sin_family = PF_INET;
    sockAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    sockAddr.sin_port = htons(827);

    connect(s, (SOCKADDR *)&sockAddr, sizeof(SOCKADDR));

    char szBuffer[MAXBYTE] = {0};

    recv(s, szBuffer, MAXBYTE, 0);

    printf("szBuffer = %s\n", szBuffer);

    closesocket(s);

    WSACleanup();
    return 0;
}

服务器端

客户端