#include <stdio.h>

 #include <stdlib.h>

 #include <WinSock2.h>

 #define BUF_SIZE 1024

 void ErrorHandling(char *message);

 void CompressSockets(SOCKET hSockArr[], int idx, int total);

 void CompressEvents(WSAEVENT hEventArr[], int idx, int total);

 int main(int argc, char *argv[])

 {

     if (argc != ) {

         printf("Usage : %s <port>\n", argv[]);

         exit();

     }

     WSADATA wsaData;

     SOCKET hServSock, hClntSock;

     SOCKADDR_IN servAdr, clntAdr;

     SOCKET hSockArr[WSA_MAXIMUM_WAIT_EVENTS];

     WSAEVENT hEventArr[WSA_MAXIMUM_WAIT_EVENTS];

     WSAEVENT newEvent;

     WSANETWORKEVENTS netEvents;

     int numOfClntSock = ;

     int strLen;

     int posInfo, startIdx;

     int clntAdrLen;

     char msg[BUF_SIZE];

     if (WSAStartup(MAKEWORD(, ), &wsaData) != )

         ErrorHandling("WSAStartup() error.");

     hServSock = socket(PF_INET, SOCK_STREAM, );

     if (hServSock == INVALID_SOCKET)

         ErrorHandling("socket() error.");

     memset(&servAdr, , sizeof(servAdr));

     servAdr.sin_family = AF_INET;

     servAdr.sin_addr.s_addr = htonl(INADDR_ANY);

     servAdr.sin_port = htons(atoi(argv[]));

     if (bind(hServSock, (SOCKADDR*)&servAdr, sizeof(servAdr)) == SOCKET_ERROR)

         ErrorHandling("bind() error.");

     if (listen(hServSock, ) == SOCKET_ERROR)

         ErrorHandling("listen() error.");

     newEvent = WSACreateEvent();

     if (WSAEventSelect(hServSock, newEvent, FD_ACCEPT) == SOCKET_ERROR)

         ErrorHandling("WSAEventSelect() error.");

     hSockArr[numOfClntSock] = hServSock;

     hEventArr[numOfClntSock] = newEvent;

     numOfClntSock++;

     printf("Server start...\n");

     while ()

     {

         posInfo = WSAWaitForMultipleEvents(numOfClntSock, hEventArr, FALSE, WSA_INFINITE, FALSE);

         startIdx = posInfo - WSA_WAIT_EVENT_0;

         for (int i = startIdx; i < numOfClntSock; i++){

             int sigEventIdx = WSAWaitForMultipleEvents(, &hEventArr[i], TRUE, , FALSE);

             if (sigEventIdx == WSA_WAIT_FAILED || sigEventIdx == WSA_WAIT_TIMEOUT){

                 continue;

             }

             else{

                 sigEventIdx = i;

                 WSAEnumNetworkEvents(hSockArr[sigEventIdx], hEventArr[sigEventIdx], &netEvents);

                 if (netEvents.lNetworkEvents & FD_ACCEPT){ // 客户端请求连接

                     if (netEvents.iErrorCode[FD_ACCEPT_BIT] != )

                     {

                         printf("Accept error.\n");

                         break;

                     }

                     clntAdrLen = sizeof(clntAdr);

                     hClntSock = accept(hSockArr[sigEventIdx], (SOCKADDR*)&clntAdr, &clntAdrLen);

                     newEvent = WSACreateEvent();

                     WSAEventSelect(hClntSock, newEvent, FD_READ | FD_CLOSE);

                     hEventArr[numOfClntSock] = newEvent;

                     hSockArr[numOfClntSock] = hClntSock;

                     numOfClntSock++;

                     printf("connected new client...\n");

                 }

                 if (netEvents.lNetworkEvents & FD_READ){ // 接收数据

                     if (netEvents.iErrorCode[FD_READ_BIT] != )

                     {

                         printf("Read error\n");

                         break;

                     }

                     strLen = recv(hSockArr[sigEventIdx], msg, sizeof(msg), );

                     send(hSockArr[sigEventIdx], msg, strLen, );

                 }

                 if (netEvents.lNetworkEvents & FD_CLOSE){ // 断开连接

                     if (netEvents.iErrorCode[FD_CLOSE_BIT] != )

                     {

                         printf("Close Error.\n");

                         break;

                     }

                     WSACloseEvent(hEventArr[sigEventIdx]);

                     closesocket(hSockArr[sigEventIdx]);

                     numOfClntSock--;

                     CompressSockets(hSockArr, sigEventIdx, numOfClntSock);

                     CompressEvents(hEventArr, sigEventIdx, numOfClntSock);

                 }

             }

         }

     }

     WSACleanup();

     return ;

 }

 void ErrorHandling(char *message) {

     fputs(message, stderr);

     fputc('\n', stderr);

 }

 void CompressSockets(SOCKET hSockArr[], int idx, int total){

     for (int i = idx; i < total; i++)

         hSockArr[i] = hSockArr[i + ];

 }

 void CompressEvents(WSAEVENT hEventArr[], int idx, int total){

     for (int i = idx; i < total; i++)

         hEventArr[i] = hEventArr[i + ];

 }

 #pragma warning(disable:4996)

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

 #include <winsock2.h>

 #define BUF_SIZE 1024

 void ErrorHandling(char *message);

 int main(int argc, char* argv[]) {

     if (argc != ) {

         printf("Usage : %s <IP> <port>\n", argv[]);

         exit();

     }

     WSADATA wsaData;

     SOCKET sock;

     SOCKADDR_IN serverAddr;

     char message[BUF_SIZE];

     int sLen, recvLen;

     if (WSAStartup(MAKEWORD(, ), &wsaData) != )

         ErrorHandling("WSAStartup() error");

     sock = socket(PF_INET, SOCK_STREAM, );

     if (sock == INVALID_SOCKET)

         ErrorHandling("socket() error");

     memset(&serverAddr, , sizeof(serverAddr));

     serverAddr.sin_family = AF_INET;

     serverAddr.sin_addr.s_addr = inet_addr(argv[]);

     serverAddr.sin_port = htons(atoi(argv[]));

     if (connect(sock, (SOCKADDR*)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR)

         ErrorHandling("connect() error");

     else

         printf("Connected.......\n");

     while ()

     {

         fputs("Input message(Q to quit):", stdout);

         fgets(message, BUF_SIZE, stdin);

         if (!strcmp(message, "q\n") || !strcmp(message, "Q\n"))

             break;

         sLen = send(sock, message, strlen(message), );

         recvLen = ;

         while (recvLen < sLen) {

             int cnt = recv(sock, message, BUF_SIZE - , );

             if (cnt == -)

                 ErrorHandling("ercv() error");

             recvLen += cnt;

         }

         message[recvLen] = ;

         printf("Message from server: %s\n", message);

     }

     closesocket(sock);

     WSACleanup();

     return ;

 }

 void ErrorHandling(char *message) {

     fputs(message, stderr);

     fputc('\n', stderr);

 }