简单的广播收发

向局域网发送广播：server.c

Int main()
{
Int sockfd;
Struct sockaddr_in server_addr, client_addr;
Int broadcast_en = 1;
Socklen_t broadcast_len = sizeof(broadcast_en);

Char buf[] = "good luck";


Bzero(&server_addr, sizeof(server_addr));
Bzero(&client_addr, sizeof(client_addr));


Server_addr.sin_family = AF_INET;
Server_addr.sin_port = htons(2222);
Server_addr.sin_addr.s_add=inet_addr("192.168.220.255");


Sockfd = socket(AF_INET, SOCK_DGRAM, 0);


Setsocketopt(sockfd, SOL_SOCKET, SO_BROADCAST, &broadcast_en, broadcast_len);


Sendto(sockfd, buf, sizeof(buf), 0, (struct sockaddr *)&clinet_addr, sizeof(client_addr));


}

定义套接字，命名套接字，向ip段局域网中发送广播信息；
接受广播：client.c

Int main()
{
Int servfd;
Struct Sockaddr_in server_addr,client_addr;
Char buf[] = " ";


Int len = sizeof(server_addr)
Bzero(&server_addr,sizeof(server_addr));
Bzero(&client_addr, sizeof(client_addr));


Servfd = socket(AF_INET, SOCK_DGRAM, 0 );
Server_addr.sin_famliy = AF_INET;
Server_addr.sin_port = htons(2222);//端口一定要一样
Server_addr.sin_addr.s_addr = htonl(INADDR_ANY);


Blind(server_addr, (struct sockaddr *)&server_addr, len);

Recvfrom(servfd, buf, 100, 0, (struct sockaddr *)&client_addr, sizeof(client_addr));


Printf("recv %s\n",buf);
Return 1;


}

定义套接字，绑定地址，命名套接字，收广播信息buf;