UDP广播发送和接收的VC程序

/* * UdpBroadMain.c * UDP广播程序 */ #include <windows.h> #include <stdio.h> #include <time.h> #include <winsock.h> #include <CONIO.H> #pragma comment(lib, "Ws2_32.lib") int main( int argc, char *argv[] ) { WSADATA wsaData; SOCKET s; struct sockaddr_in sin, sto; char pBuf[1024]; bool fBroadcase = true; int ncount = 0; // 检查WinSock版本，不能低于1.1 if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) { printf("\r\nUnable to initialize WinSock for host info"); exit(0); } // 创建客户端套接字 s = socket( AF_INET, SOCK_DGRAM, 0 ); // UDP if( s < 0 ) { printf("failed socket (%d)\n",WSAGetLastError()); goto leave; } // 设置套接字为广播形式 setsockopt( s, SOL_SOCKET, SO_BROADCAST, (char*)&fBroadcase, sizeof(bool) ); sin.sin_family = AF_INET; sin.sin_addr.s_addr = htonl(INADDR_ANY); // 本机IP地址 sin.sin_port = htons(0); // 随机分配端口 // 绑定套接字，不绑定，系统会自动为套接字指定本机IP地址和随机分配端口号 if ( bind( s, (struct sockaddr*)&sin, sizeof(sin) ) != 0 ) { printf("failed bind socket (%d)\n",WSAGetLastError()); goto leave; } sto.sin_family = AF_INET; /* sto.sin_addr.s_addr = htonl(INADDR_BROADCAST); // 指定广播地址255.255.255.255*/ sto.sin_addr.s_addr = inet_addr("192.168.0.255"); // 局域网192.168.0.xxx内的广播 sto.sin_port = htons(7001); // 发送到端口 while( !_kbhit() ) // 检查是否有键盘输入，无输入则继续执行，有输入则结束循环 { sprintf( pBuf, "Message %d", ncount++); sendto( s, pBuf, lstrlen(pBuf), 0, (struct sockaddr*)&sto, sizeof(sockaddr_in) ); // 接收数据 printf("Send To %s:%d : %s\n", inet_ntoa(sto.sin_addr), ntohs(sto.sin_port), pBuf ); Sleep(1000); // 等待1s，降低发送速度 } leave: if( s >= 0 ) closesocket( s ); WSACleanup(); return 0; }