Winsock Select模型范例

服务器端：
#include <Winsock2.h>
#include <stdio.h>

void InitSocket()
{
WORD wVersionRequested;
WSADATA wsaData;
int err;

wVersionRequested = MAKEWORD( 2, 2 );

err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
/* Tell the user that we could not find a usable */
/* WinSock DLL. */
return;
}

/* Confirm that the WinSock DLL supports 2.2.*/
/* Note that if the DLL supports versions greater */
/* than 2.2 in addition to 2.2, it will still return */
/* 2.2 in wVersion since that is the version we */
/* requested. */

if ( LOBYTE( wsaData.wVersion ) != 2 ||
HIBYTE( wsaData.wVersion ) != 2 ) {
/* Tell the user that we could not find a usable */
/* WinSock DLL. */
WSACleanup( );
return;
}
}
int main(int argc, char* argv[])
{
InitSocket();
SOCKET sock=::socket(AF_INET,SOCK_STREAM,0);
if(sock==INVALID_SOCKET)
{
printf("创建socket失败");
WSACleanup( );
return 0;
}
//::sockaddr_in serAddr;
SOCKADDR_IN serAddr;
serAddr.sin_family=AF_INET;
serAddr.sin_port=::htons(5150);
serAddr.sin_addr.s_addr = htonl(INADDR_ANY);
if(SOCKET_ERROR==bind(sock,(sockaddr*)&serAddr,sizeof(sockaddr)))
{
printf("绑定失败");
WSACleanup( );
return 0;
}
listen(sock,5);
fd_set fdSocket;
FD_ZERO(&fdSocket);
FD_SET(sock,&fdSocket);
while(true)
{
fd_set fdRead=fdSocket;
int nRet=::select(0,&fdRead,NULL,NULL,NULL);
if(nRet>0)
{
for(int i=0;i<(int)fdSocket.fd_count;i++)
{
if(FD_ISSET(fdSocket.fd_array[i],&fdRead))
{
//有新的连接到达
if(fdSocket.fd_array[i]==sock)
{
if(fdSocket.fd_count<FD_SETSIZE)
{
::sockaddr_in addr;
int len=sizeof(sockaddr);
SOCKET client=accept(sock,(sockaddr*)&addr,&len);
printf("接收到新的连接 : %s/n",::inet_ntoa(addr.sin_addr));
FD_SET(client,&fdSocket);
}
else
{
printf("too many connections/n");
}
}
else
{
char*buf=new char[1024];
int nRecv=::recv(fdSocket.fd_array[i],buf,1024,0);
if(nRecv>0)
{
buf[nRecv]='/0';
printf("收到数据: %s/n",buf);
}
else
{
::closesocket(fdSocket.fd_array[i]);
FD_CLR(fdSocket.fd_array[i],&fdSocket);
printf("一客户端断开连接/n");
}
delete []buf;
}
}
}
}
}
return 0;
}

客户端：

#include <winsock2.h>
#include <stdio.h>
#include <memory.h>
#include <iostream>
#include <string>
using namespace std;

void main(int argc, char **argv)
{
WSADATA wsaData;
SOCKET s;
SOCKADDR_IN ServerAddr;
int Port = 5150;
int Ret, Ret1;
string Data;
char DataServe[8];
memset(DataServe, 0, 8);
char pause;

if (argc <= 1)
{
printf("USAGE: tcpclient <Server IP address>./n");
return;
}

// Initialize Winsock version 2.2

if ((Ret = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0)
{
// NOTE: Since Winsock failed to load we cannot use WSAGetLastError
// to determine the error code as is normally done when a Winsock
// API fails. We have to report the return status of the function.

printf("WSAStartup failed with error %d/n", Ret);
return;
}

// Create a new socket to make a client connection.

if ((s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP))
== INVALID_SOCKET)
{
printf("socket failed with error %d/n", WSAGetLastError());
WSACleanup();
return;
}

// Setup a SOCKADDR_IN structure that will be used to connect
// to a listening server on port 5150. For demonstration
// purposes, we required the user to supply an IP address
// on the command line and we filled this field in with the
// data from the user.

ServerAddr.sin_family = AF_INET;
ServerAddr.sin_port = htons(Port);
ServerAddr.sin_addr.s_addr = inet_addr(argv[1]);

// Make a connection to the server with socket s.

printf("We are trying to connect to %s:%d.../n",
inet_ntoa(ServerAddr.sin_addr), htons(ServerAddr.sin_port));

if (connect(s, (SOCKADDR *) &ServerAddr, sizeof(ServerAddr))
== SOCKET_ERROR)
{
printf("connect failed with error %d/n", WSAGetLastError());
closesocket(s);
WSACleanup();
return;
}

printf("Our connection succeeded./n");

// At this point you can start sending or receiving data on
// the socket s. We will just send a hello message to the server.

printf("We will now try to send a hello message./n");

for(int i = 0; i<3; i++)
{
cin>>Data;
if ((Ret = send(s, Data.c_str()/*"Hello"*/, Data.size(), 0)) == SOCKET_ERROR)
{
printf("send failed with error %d/n", WSAGetLastError());
closesocket(s);
WSACleanup();
return;
}
printf("We successfully sent %d byte(s)./n", Ret);
}

// When you are finished sending and receiving data on socket s,
// you should close the socket.

printf("We are closing the connection./n");

closesocket(s);

// When your application is finished handling the connection, call
// WSACleanup.

WSACleanup();
cin>>pause;
}