C++实现简单的UDP服务端与flag参数解析

  1 #include <iostream>
  2 #include <string>
  3 
  4 #include <time.h>
  5 
  6 #include <WinSock2.h>
  7 
  8 #pragma comment(lib,"ws2_32.lib")
  9 
 10 static int g_iPause;
 11 
 12 #define APP_END             std::cin >> g_iPause; return
 13 #define _MAX_LEN            2048
 14 #define _SOCK_ADDR_LEN      sizeof(SOCKADDR)
 15 #define _STRING_EQUAL       0
 16 #define _WSASTARTUP_SUCCESS 0
 17 
 18 void main()
 19 {
 20   WORD wVerRes;
 21   WSADATA wsaData;
 22 
 23   wVerRes = WINSOCK_VERSION;
 24 
 25   if (_WSASTARTUP_SUCCESS != WSAStartup(wVerRes, &wsaData))
 26   {
 27     std::cout << "!!!WSAStartup failure" << std::endl;
 28     APP_END;
 29   }
 30 
 31   //WINSOCK_VERSION展开后是MAKEWORD(2,2),这里要比对上
 32   if ((2 != LOBYTE(wsaData.wVersion)) || (2 != HIBYTE(wsaData.wVersion)))
 33   {
 34     std::cout << "!!!Incorrect Version" << std::endl;
 35     WSACleanup();
 36     APP_END;
 37   }
 38 
 39   SOCKET sockUdpSrv = socket(AF_INET, SOCK_DGRAM, 0);
 40   SOCKADDR_IN addrSrv;
 41   addrSrv.sin_family = AF_INET;
 42   addrSrv.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
 43   addrSrv.sin_port = htons(8888);
 44 
 45   if (SOCKET_ERROR == bind(sockUdpSrv, (SOCKADDR*)&addrSrv, _SOCK_ADDR_LEN))
 46   {
 47     std::cout << "!!!bind Error" << std::endl;
 48     closesocket(sockUdpSrv);
 49     WSACleanup();
 50     APP_END;
 51   }
 52 
 53   char *recvBuf = new char[_MAX_LEN];
 54   char *sendBuf = new char[_MAX_LEN];
 55   memset(recvBuf, 0, _MAX_LEN);
 56   memset(sendBuf, 0, _MAX_LEN);
 57 
 58   SOCKADDR_IN addrClient;
 59   int iFromLen = _SOCK_ADDR_LEN;
 60 
 61   std::cout << "udp server is running..." << std::endl;
 62   while (true)
 63   {
 64     //接收
 65     if (SOCKET_ERROR == recvfrom(sockUdpSrv, recvBuf, _MAX_LEN, 0, (SOCKADDR*)&addrClient, &iFromLen))
 66     {
 67       continue;
 68     }
 69 
 70     //时间戳
 71     time_t sys_time = time(NULL);
 72     std::string sTime_label = asctime(gmtime(&sys_time));
 73     sTime_label[sTime_label.length() - 1] = '\0';
 74 
 75     //客户端ip地址
 76     std::string sClient_ip = inet_ntoa(addrClient.sin_addr);
 77 
 78     std::cout << sTime_label
 79               << " recv msg from "
 80               << sClient_ip
 81               << " : "
 82               << recvBuf
 83               << std::endl;
 84 
 85     memcpy(sendBuf, recvBuf, _MAX_LEN);
 86 
 87     sendto(sockUdpSrv, sendBuf, _MAX_LEN, 0, (SOCKADDR*)&addrClient, _SOCK_ADDR_LEN);
 88 
 89     if (0 == strcmp(recvBuf, "stop"))
 90     {
 91       break;
 92     }
 93 
 94     memset(recvBuf, 0, _MAX_LEN);
 95     memset(sendBuf, 0, _MAX_LEN);
 96   }
 97 
 98   delete recvBuf;
 99   delete sendBuf;
100   recvBuf = nullptr;
101   sendBuf = nullptr;
102   closesocket(sockUdpSrv);
103   WSACleanup();
104 
105   APP_END;
106 }