socket编程：select 用法 例子

服务器：

#include <stdio.h>   
#include <string.h>   
#include <WINSOCK2.H>   
  
#pragma comment(lib,"ws2_32.lib")   
  
#define INT_SERVER_PORT 6002   
#define STR_SERVER_IP "127.0.0.1"   
#define INT_DATABUFFER_SIZE 100   
  
void main(void)  
{  
    WORD dwVersion = MAKEWORD(2,2);  
    WSAData wsaData;  
    WSAStartup(WINSOCK_VERSION,&wsaData);  
  
    SOCKET sockServer = socket(AF_INET,SOCK_STREAM,0);  
    if (INVALID_SOCKET == sockServer)  
    {  
        printf("Failed to create socket!/r/n");  
        WSACleanup();  
        return;  
    }  
  
    sockaddr_in addrServer;  
    memset(&addrServer,0,sizeof(sockaddr_in));  
    addrServer.sin_family = AF_INET;  
    addrServer.sin_port = htons(INT_SERVER_PORT);  
    addrServer.sin_addr.S_un.S_addr = htonl(INADDR_ANY);  
    //addrServer.sin_addr.s_addr = htonl(INADDR_ANY);   
  
    int iResult;  
  
    bool bReuseAddr=true;  
    iResult=setsockopt(sockServer,SOL_SOCKET,SO_REUSEADDR,(char *)&bReuseAddr,sizeof(bReuseAddr));  
    if(SOCKET_ERROR == iResult)  
    {  
        printf("Failed to set resueaddr socket!/r/n");  
        WSACleanup();  
        return;  
    }  
      
    /* 
    unsigned   long cmd = 1;  
    iResult= ioctlsocket(sockServer,FIONBIO,&cmd); */  
  
    iResult = bind(sockServer,(sockaddr *)&addrServer,sizeof(addrServer));  
    if (SOCKET_ERROR == iResult)  
    {  
        printf("Failed to bind address!/r/n");  
        WSACleanup();  
        return;  
    }  
  
    if (0 != listen(sockServer,5))  
    {  
        printf("Failed to listen client!/r/n");  
        WSACleanup();  
        return;  
    }  
  
    UINT i = 0;  
    SOCKET sockAccept;  
    sockaddr_in addrAccept;  
    int iAcceptLen = sizeof(addrAccept);  
    char szDataBuff[INT_DATABUFFER_SIZE];  
    int iRecvSize;  
      
    sockaddr_in addrTemp;  
    int iTempLen;  
  
    fd_set fd;  
    FD_ZERO(&fd);  
    FD_SET(sockServer,&fd);  
  
    /* 
    timeval tm; 
    tm.tv_sec = 0; 
    tm.tv_usec = 1000; 
    */  
    printf("Start server.../r/n");  
    while(1)  
    {  
        fd_set fdOld = fd;  
        iResult = select(0,&fdOld,NULL,NULL,/*&tm*/NULL);  
        if (0 <= iResult)  
        {  
            for(i = 0;i < fd.fd_count; i++)  
            {  
                if (FD_ISSET(fd.fd_array[i],&fdOld))  
                {  
                    //如果socket是服务器，则接收连接   
                    if (fd.fd_array[i] == sockServer)  
                    {  
                        memset(&addrAccept,0,sizeof(addrTemp));  
                        sockAccept = accept(sockServer,(sockaddr *)&addrAccept,&iAcceptLen);  
                        if (INVALID_SOCKET != sockAccept)  
                        {  
                            FD_SET(sockAccept,&fd);  
                            //FD_SET(sockAccept,&fdOld);   
                            printf("%s:%d has connected server!/r/n",inet_ntoa(addrAccept.sin_addr),  
                                ntohs(addrAccept.sin_port));  
                        }  
                    }  
                    else //非服务器,接收数据(因为fd是读数据集)   
                    {  
                        memset(szDataBuff,0,INT_DATABUFFER_SIZE);  
                        iRecvSize = recv(fd.fd_array[i],szDataBuff,INT_DATABUFFER_SIZE,0);  
                        memset(&addrTemp,0,sizeof(addrTemp));  
                        iTempLen = sizeof(addrTemp);  
                        getpeername(fd.fd_array[i],(sockaddr *)&addrTemp,&iTempLen);  
                          
                        if (SOCKET_ERROR == iRecvSize)  
                        {  
                            closesocket(fd.fd_array[i]);  
                            FD_CLR(fd.fd_array[i],&fd);  
                            i--;  
                            printf("Failed to recv data ,%s:%d errorcode:%d./r/n",  
                                inet_ntoa(addrTemp.sin_addr),ntohs(addrTemp.sin_port),WSAGetLastError());  
                            continue;  
                        }  
  
                        if (0 == iRecvSize)  
                        {  
                            //客户socket关闭   
                            printf("%s:%d has closed!/r/n",inet_ntoa(addrTemp.sin_addr),  
                                ntohs(addrTemp.sin_port));  
                              
                            closesocket(fd.fd_array[i]);  
                            FD_CLR(fd.fd_array[i],&fd);  
                            i--;      
                        }  
                          
                        if (0 < iRecvSize)  
                        {  
                            //打印接收的数据   
                            printf("recv %s:%d data:%s/r/n",inet_ntoa(addrTemp.sin_addr),  
                                ntohs(addrTemp.sin_port),szDataBuff);  
                        }  
                    }     
                }  
            }  
        }  
        else if (SOCKET_ERROR == iResult)  
        {  
            //WSACleanup();    
        //  printf("Faild to select sockt in server!/r/n");   
            Sleep(100);  
        }  
    }  
    WSACleanup();  
}  

客户端：

#include <stdio.h>   
#include <string.h>   
#include <WINSOCK2.H>   
  
#pragma comment(lib,"ws2_32.lib")   
  
#define INT_SERVER_PORT 6002   
#define STR_SERVER_IP "127.0.0.1"   
#define INT_DATABUFFER_SIZE 100   
#define STR_EXIT "exit"   
  
void main(void)  
{  
    WSAData wsaData;  
    WSAStartup(WINSOCK_VERSION,&wsaData);  
  
    SOCKET sockClient = socket(AF_INET,SOCK_STREAM,0);  
    if (INVALID_SOCKET == sockClient)  
    {  
        printf("Failed to create client!/r/n");  
        WSACleanup();  
    }  
  
    sockaddr_in addrClient;  
    addrClient.sin_addr.S_un.S_addr = inet_addr(STR_SERVER_IP);  
    addrClient.sin_family = AF_INET;  
    addrClient.sin_port = htons(INT_SERVER_PORT);  
  
      
    int iResult;  
    iResult = connect(sockClient,(sockaddr *)&addrClient,sizeof(sockaddr_in));  
    if (SOCKET_ERROR == iResult)  
    {  
        printf("Failed to connect server!/r/n");  
        WSACleanup();  
        return;   
    }   
  
    if (0 != iResult)  
    {  
        int iErrorCode;  
        iErrorCode = WSAGetLastError();  
        printf("Failed to connect server,error:%d./r/n",iErrorCode);  
        WSACleanup();  
        return;  
    }  
    char szDataBuffer[INT_DATABUFFER_SIZE];  
    while(1)  
    {  
        memset(szDataBuffer,0,INT_DATABUFFER_SIZE);  
        scanf("%s",szDataBuffer);  
  
        if (0 == strcmp(szDataBuffer,STR_EXIT))  
        {  
            printf("The client has stopped!/r/n");  
            break;  
        }  
        else  
        {  
            if (1 > send(sockClient,szDataBuffer,strlen(szDataBuffer),0))  
            {  
                printf("Failed to send data!/r/n");  
            }  
        }  
        Sleep(100);  
    }  
    closesocket(sockClient);  
    WSACleanup();  
  
}