广播发送与接收

//发送端

#include <iostream>

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

using namespace std;

int main()

{

    WSADATA wsaData;
    short version = MAKEWORD(2,0);
    WSAStartup(version,&wsaData); //初始化socket

    int sock = -1;
    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
    {
        cout<<"socket error"<<endl;
        return false;
    }

    const int opt = 1;
    //设置该套接字为广播类型，
    int nb = 0;
    nb = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&opt, sizeof(opt));
    if(nb == -1)
    {
        cout<<"set socket error..."<<endl;
        return false;
    }

    struct sockaddr_in addrto;
    bzero(&addrto, sizeof(struct sockaddr_in));
    addrto.sin_family=AF_INET;
    addrto.sin_addr.s_addr=htonl(INADDR_BROADCAST);
    addrto.sin_port=htons(6000);
    int nlen=sizeof(addrto);

    while(1)
    {
        sleep(1);
        //从广播地址发送消息
        char smsg[] = {"broadcast msg"};
        int ret=sendto(sock, smsg, strlen(smsg), 0, (sockaddr*)&addrto, nlen);
        if(ret<0)
        {
            cout<<"send error...."<<ret<<endl;
        }
        else
        {
            printf("ok ");
        }
    }

    return 0;

}

//接收端

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <winsock2.h>

using namespace std;

int main()
{
    WSADATA wsaData;
    short version = MAKEWORD(2,0);
    WSAStartup(version,&wsaData); //初始化socket

    // 绑定地址
    struct sockaddr_in addrto;
    memset(&addrto, 0, sizeof(struct sockaddr_in));
    addrto.sin_family = AF_INET;
    addrto.sin_addr.s_addr = htonl(INADDR_ANY);
    addrto.sin_port = htons(6000);

    // 对端地址
    struct sockaddr_in from;
    memset(&from, 0, sizeof(struct sockaddr_in));

    int sock = -1;
    if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
    {
        cout<<"socket error"<<endl;
        return false;
    }

    const int opt = 1;
    //设置该套接字为广播类型，
    int nb = 0;
    nb = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&opt, sizeof(opt));
    if(nb == -1)
    {
        cout<<"set socket error..."<<endl;
        return false;
    }

    if(bind(sock,(struct sockaddr *)&(addrto), sizeof(struct sockaddr_in)) == -1)
    {
        cout<<"bind error..."<<endl;
        return false;
    }

int len = sizeof(sockaddr_in);
char smsg[100] = {0};

    while(1)
    {
        //从广播地址接受消息
        int ret=recvfrom(sock, smsg, 100, 0, (struct sockaddr*)&from,&len);
        if(ret<=0)
        {
            cout<<"read error...."<<sock<<endl;
        }
        else
        {
            printf("%s\n", smsg);
        }

}

return 0;
}

补充：综合编程 , 其他综合 ,