发送端

#include<stdio.h>
#include<Windows.h>
#include<windows.h>
#include<WinSock2.h>
#include<string.h>
#include<stdlib.h>
#define ERR_OR(msg) do{\
fprintf(stderr, "__%d__", __LINE__);\
perror(msg);\
}while(0)
constexpr auto IP = "192.168.122.88";
constexpr auto PORT = 8888;
int main()
{
	int cfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (cfd<0)
	{
		ERR_OR("socket");
		return -1;
	}
	printf("cfd=%d\n", cfd);
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	char buf[128];
	int num = 0;
	while (num<15)
	{
		num++;
		memset(buf,0, sizeof(buf));
		fgets(buf, sizeof(buf), stdin);
		buf[strlen(buf) - 1] = '\0';
		if (sendto(cfd,buf,sizeof(buf),0,(struct sockaddr*)&sin,sizeof(sin))<0)
		{
			ERR_OR("sendto");
			return -1;
		}
		puts("sendto sucss");
	}
	closesocket(cfd);
	return 0;
}

接收端

#include<myy.h>
#define ERR_OR(msg) do{\
	fprintf(stderr,"__%d__",__LINE__);\
	perror(msg);\
}while(0)
#define GIP "224.1.2.3"
#define LIP "192.168.123.92"
#define PORT 8888
int main()
{
	int sfd=socket(AF_INET,SOCK_DGRAM,0);
	if (sfd<0)
	{
		ERR_OR(msg);
		return -1;
	}
	printf("sfd=%d\n",sfd);

	struct ip_mreqn mq;
	mq.imr_multiaddr.s_addr=inet_addr(GIP);
	mq.imr_address.s_addr  =inet_addr(LIP);
	mq.imr_ifindex         =0;
	printf("加入小组成功%s,端口%d\n",GIP,PORT);

	struct sockaddr_in sin;
	sin.sin_family     =AF_INET;
	sin.sin_port       =htons(PORT);
	sin.sin_addr.s_addr=inet_addr(GIP);
	if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin))<0)
	{
		ERR_OR("bind");
		return -1;
	}
	puts("bind YES");
	struct sockaddr_in cin;
	socklen_t addrlen=sizeof(cin);
	char buf[128];
	int num=0;
	while(num<15)
	{
		num++;
		bzero(buf,sizeof(buf));
		if(recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,&addrlen)<0)
		{
			ERR_OR("recvfrom");
			return -1;
		}

		printf("[%s:%d]:%s\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),buf);
	}
	close(sfd); 

	return 0;
}