windows socket编程：select 用法 例子

http://blog.csdn.net/zjsiva/article/details/5895087

服务器端：

#include <stdio.h>  
#include <string.h>  
#include <WINSOCK2.H>  
  
#pragma comment(lib,"ws2_32.lib")  
  
#define INT_SERVER_PORT 5000  
#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!\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!\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!\n");  
        WSACleanup();  
        return;  
    }  
  
    if (0 != listen(sockServer,5))  
    {  
        printf("Failed to listen client!\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...\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!\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.\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!\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\n",inet_ntoa(addrTemp.sin_addr),  
                                ntohs(addrTemp.sin_port),szDataBuff);  
                        }  
                    }     
                }  
            }  
        }  
        else if (SOCKET_ERROR == iResult)  
        {  
            //WSACleanup();   
        //  printf("Faild to select sockt in server!\n");  
            Sleep(100);  
        }  
    }  
    WSACleanup();  
}  

客户端可以直接用nc，即netcat