select Demo

  1 #include <iostream>
  2 #include <WinSock2.h>
  3 
  4 using namespace std;
  5 
  6 #pragma comment(lib, "ws2_32")
  7 
  8 int main(int argc, char **argv)
  9 {
 10     WSADATA wsaData;
 11     WSAStartup(WINSOCK_VERSION, &wsaData);
 12 
 13     USHORT uPort = 4567;
 14     SOCKET sListen = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 15     if (INVALID_SOCKET == sListen)
 16     {
 17         cout << "socket error : " << GetLastError() << endl;
 18         return 0;
 19     }
 20 
 21     SOCKADDR_IN sin;
 22     sin.sin_family = AF_INET;
 23     sin.sin_port = htons(uPort);
 24     sin.sin_addr.S_un.S_addr = INADDR_ANY;
 25 
 26     if (SOCKET_ERROR == bind(sListen, (PSOCKADDR)&sin, sizeof(sin)))
 27     {
 28         cout << "Bind error : " << WSAGetLastError() << endl;
 29         closesocket(sListen);
 30         WSACleanup();
 31         return 0;
 32     }
 33 
 34     if (SOCKET_ERROR == listen(sListen, 5))
 35     {
 36         cout << "listen error : " << WSAGetLastError() << endl;
 37         closesocket(sListen);
 38         WSACleanup();
 39         return 0;
 40     }
 41 
 42     fd_set fdSocket;
 43     FD_ZERO(&fdSocket);
 44     FD_SET(sListen, &fdSocket);
 45 
 46     while (TRUE)
 47     {
 48         fd_set fdRead = fdSocket;
 49         int iRet = select(0, &fdRead, NULL, NULL, NULL);
 50         if (iRet > 0)
 51         {
 52             for (size_t i = 0; i < fdSocket.fd_count; i++)
 53             {
 54                 if (FD_ISSET(fdSocket.fd_array[i], &fdRead))
 55                 {
 56                     if (fdSocket.fd_array[i] == sListen)
 57                     {
 58                         if (fdSocket.fd_count < FD_SETSIZE)
 59                         {
 60                             SOCKADDR_IN addrRemote;
 61                             int iAddrLen = sizeof(addrRemote);
 62                             SOCKET sNew = accept(sListen, (PSOCKADDR)&addrRemote, &iAddrLen);
 63                             FD_SET(sNew, &fdSocket);
 64                             cout << "接收到连接（" << inet_ntoa(addrRemote.sin_addr) << "）" << endl;
 65                         }
 66                         else
 67                         {
 68                             cout << "连接太多!" << endl;
 69                             continue;
 70                         }
 71                     }
 72                     else
 73                     {
 74                         char szText[256];
 75                         int iRecv = recv(fdSocket.fd_array[i], szText, strlen(szText), 0);
 76                         if (iRecv > 0)
 77                         {
 78                             szText[iRecv] = '';
 79                             cout << "接收到数据：" << szText << endl;
 80                         }
 81                         else
 82                         {
 83                             closesocket(fdSocket.fd_array[i]);
 84                             FD_CLR(fdSocket.fd_array[i], &fdSocket);
 85                         }
 86                     }
 87                 }
 88             }
 89         }
 90         else
 91         {
 92             cout << "select error : " << WSAGetLastError() << endl;
 93             closesocket(sListen);
 94             WSACleanup();
 95             break;
 96         }
 97     }
 98 
 99     shutdown(sListen, SD_RECEIVE);
100     WSACleanup();
101 
102     return 0;
103 }