c++之 socket 通信，还有IOCP

 关于IOCP的一篇不错的文章：

http://blog.csdn.net/neicole/article/details/7549497

 http://www.cnblogs.com/Sniper-quay/archive/2011/06/22/2086636.html

基本的阻塞I/O模式（下面代码转自CSDN）：

服务器：

// Server.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "winsock2.h"
#pragma comment(lib, "ws2_32.lib")
#include <iostream>
using namespace std;
int _tmain(int argc, char* argv[])
{
    const int BUF_SIZE = 64;
    WSADATA            wsd;            //WSADATA变量
    SOCKET            sServer;        //服务器套接字
    SOCKET            sClient;        //客户端套接字
    SOCKADDR_IN        addrServ;;        //服务器地址
    char            buf[BUF_SIZE];    //接收数据缓冲区
    char            sendBuf[BUF_SIZE];//返回给客户端得数据
    int                retVal;            //返回值
    //初始化套结字动态库
    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
    {
        cout << "WSAStartup failed!" << endl;
        return 1;
    }
    
    //创建套接字
    sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    
    if(INVALID_SOCKET == sServer)
    {
        cout << "socket failed!" << endl;
        WSACleanup();//释放套接字资源;
        return  -1;
    }
    
    //服务器套接字地址 
    addrServ.sin_family = AF_INET;
    addrServ.sin_port = htons(4999);
    addrServ.sin_addr.s_addr = INADDR_ANY;        
    //绑定套接字
    retVal = bind(sServer, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN));
    if(SOCKET_ERROR == retVal)
    {    
        cout << "bind failed!" << endl;
        closesocket(sServer);    //关闭套接字
        WSACleanup();            //释放套接字资源;
        return -1;
    }
    
    //开始监听 
    retVal = listen(sServer, 1);
    if(SOCKET_ERROR == retVal)
    {
        cout << "listen failed!" << endl;        
        closesocket(sServer);    //关闭套接字
        WSACleanup();            //释放套接字资源;
        return -1;
    }
    
    //接受客户端请求
    sockaddr_in addrClient;
    int addrClientlen = sizeof(addrClient);
    sClient = accept(sServer,(sockaddr FAR*)&addrClient, &addrClientlen);
    if(INVALID_SOCKET == sClient)
    {
        cout << "accept failed!" << endl;        
        closesocket(sServer);    //关闭套接字
        WSACleanup();            //释放套接字资源;
        return -1;
    }
    
    while(true){
        //接收客户端数据
        ZeroMemory(buf, BUF_SIZE);
        retVal = recv(sClient, buf, BUF_SIZE, 0);
        if (SOCKET_ERROR == retVal)
        {
            cout << "recv failed!" << endl;        
            closesocket(sServer);    //关闭套接字
            closesocket(sClient);    //关闭套接字        
            WSACleanup();            //释放套接字资源;
            return -1;
        }
        if(buf[0] == '0')
            break;
        cout << "客户端发送的数据: " << buf <<endl;
        
        cout << "向客户端发送数据: " ;
        cin >> sendBuf;
        
        send(sClient, sendBuf, strlen(sendBuf), 0);
    }
    
    //退出
    closesocket(sServer);    //关闭套接字
    closesocket(sClient);    //关闭套接字
    WSACleanup();            //释放套接字资源;
    
    return 0;
}

 

客户端：

// Client.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "winsock2.h"
#include <iostream>
#pragma comment(lib, "ws2_32.lib")
using namespace std;
BOOL    RecvLine(SOCKET s, char* buf);    //读取一行数据
int main(int argc, char* argv[])
{
    const int BUF_SIZE = 64;
    WSADATA            wsd;            //WSADATA变量
    SOCKET            sHost;            //服务器套接字
    SOCKADDR_IN        servAddr;        //服务器地址
    char            buf[BUF_SIZE];    //接收数据缓冲区
    char            bufRecv[BUF_SIZE];
    int                retVal;            //返回值
    
    //初始化套结字动态库
    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
    {
        cout << "WSAStartup failed!" << endl;
        return -1;
    }
    
    //创建套接字
    sHost = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    
    if(INVALID_SOCKET == sHost)
    {
        cout << "socket failed!" << endl;
        WSACleanup();//释放套接字资源
        return  -1;
    }
    //设置服务器地址
    servAddr.sin_family =AF_INET;
    servAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    servAddr.sin_port = htons((short)4999);
    int    nServAddlen  = sizeof(servAddr);
    //连接服务器
    retVal=connect(sHost,(LPSOCKADDR)&servAddr, sizeof(servAddr));    
    if(SOCKET_ERROR == retVal)
    {
        cout << "connect failed!" << endl;    
        closesocket(sHost);    //关闭套接字
        WSACleanup();        //释放套接字资源
        return -1;
    }
    while(true){
        //向服务器发送数据
        ZeroMemory(buf, BUF_SIZE);
        cout << " 向服务器发送数据:  ";
        cin >> buf;
        retVal = send(sHost, buf, strlen(buf), 0);
        if (SOCKET_ERROR == retVal)
        {
            cout << "send failed!" << endl;
            closesocket(sHost);    //关闭套接字
            WSACleanup();        //释放套接字资源
            return -1;
        }
        //RecvLine(sHost, bufRecv);
        recv(sHost, bufRecv,5 , 0);        // 接收服务器端的数据， 只接收5个字符
        cout << endl <<"从服务器接收数据：" << bufRecv;
    }
    //退出
    closesocket(sHost);    //关闭套接字
    WSACleanup();        //释放套接字资源
    return 0;
}