#include "stdafx.h"
#include <WinSock2.h>
#include <Windows.h>
#include <string.h>#pragma comment(lib, "ws2_32.lib")void autoCleanup()
{WSACleanup();
}int _tmain(int argc, _TCHAR* argv[])
{WORD wVersionRequested;WSADATA wsaData;wVersionRequested=MAKEWORD(2,2);int ret;ret = WSAStartup(wVersionRequested,&wsaData);int sock = socket(AF_INET, SOCK_DGRAM, 0);int bc = 1;//允许发送广播消息int so_broadcast = TRUE;ret = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&so_broadcast, sizeof(so_broadcast));sockaddr_in addr;addr.sin_family = AF_INET; //使用互联网际协议，即IP协议addr.sin_addr.S_un.S_addr = htonl(INADDR_ANY); addr.sin_port = htons(2526);//如果仅仅是发送广播，这一步可有可无。没有绑定也能发送广播//ret = bind(sock, (struct sockaddr *)&addr, sizeof(addr));struct sockaddr_in b_addr;b_addr.sin_family = AF_INET;b_addr.sin_addr.S_un.S_addr =htonl(INADDR_BROADCAST);b_addr.sin_port = htons(2527);char buff[50] = "Hello, world!";while (1){ret = sendto(sock, buff, strlen(buff), 0, (struct sockaddr*)&b_addr, sizeof(b_addr));printf("send... %d\n", WSAGetLastError());Sleep(3000);}closesocket(sock);atexit(autoCleanup);return 0;
}

// send.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <WinSock2.h>
#include <Windows.h>
#include <string.h>#pragma comment(lib, "ws2_32.lib")void autoCleanup()
{WSACleanup();
}int _tmain(int argc, _TCHAR* argv[])
{WORD wVersionRequested;WSADATA wsaData;wVersionRequested=MAKEWORD(2,2);WSAStartup(wVersionRequested,&wsaData);SOCKET sock = socket(AF_INET, SOCK_DGRAM, 0);struct sockaddr_in addr;addr.sin_family = AF_INET;addr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);//这个端口要和广播方广播端口一致addr.sin_port = htons(2527);bind(sock, (struct sockaddr *)&addr, sizeof(addr));struct sockaddr_in from;int len = sizeof(from);int ret;char buff[50];while (1){ret = recvfrom(sock, buff, 49, 0, (struct sockaddr *)&from, &len);if (ret > 0){buff[ret] = 0;printf("%s\n", buff);printf("%s %d\n", inet_ntoa(from.sin_addr), ntohs(from.sin_port));}}closesocket(sock);atexit(autoCleanup);return 0;
}