C++ UDP HelloWorld

////////////////////////////////////////////////////////////////////////// // UDPServer.cpp #include <stdio.h> #include <WINSOCK2.H> #pragma comment(lib,"WS2_32.lib") #define BUF_SIZE 64 int main(void) { WSADATA wsd; SOCKET s; int nRet; // 初始化套接字动态库 if(WSAStartup(MAKEWORD(2,2),&wsd) != 0) { printf("WSAStartup failed !\n"); return 1; } // 创建套接字 s = socket(AF_INET,SOCK_DGRAM,0); if(s == INVALID_SOCKET) { printf("socket() failed ,Error Code:%d\n",WSAGetLastError()); WSACleanup(); return 1; } SOCKET socketSrv = socket(AF_INET,SOCK_DGRAM,0); SOCKADDR_IN addrSrv; SOCKADDR_IN addrClient; char buf[BUF_SIZE]; int len = sizeof(SOCKADDR); // 设置服务器地址 ZeroMemory(buf,BUF_SIZE); addrSrv.sin_addr.S_un.S_addr = htonl(INADDR_ANY); addrSrv.sin_family = AF_INET; addrSrv.sin_port = htons(5000); // 绑定套接字 nRet = bind(socketSrv,(SOCKADDR*)&addrSrv,sizeof(SOCKADDR)); if(SOCKET_ERROR == nRet) { printf("bind failed !\n"); closesocket(s); WSACleanup(); return -1; } // 从客户端接收数据 nRet = recvfrom(socketSrv,buf,BUF_SIZE,0,(SOCKADDR*)&addrClient,&len); if(SOCKET_ERROR == nRet) { printf("recvfrom failed !\n"); closesocket(s); WSACleanup(); return -1; } // 打印来自客户端发送来的数据 printf("Recv From Client:%s\n",buf); // 向客户端发送数据 sendto(socketSrv,"UDP Hello World !",sizeof("UDP Hello World !"),0,(SOCKADDR*)&addrClient,len); closesocket(s); WSACleanup(); return 0; }