Winsock 传输文件

文件传输的原理：发送方把文件读到socket发送端缓冲区中，接收方把socket接收端缓端冲区中的数据写到一个新文件中。当然了，大文件需要循环读写！

服务器端为发送端：

#include "stdafx.h"

#include<winsock2.h>

#include<iostream>

#pragma comment(lib,"ws2_32.lib")

using namespace std;

int main(){

    WSADATA wsaData;

    SOCKET s;

    int errStartup,errBind;

    errStartup=WSAStartup(MAKEWORD(,),&wsaData);

    if(errStartup!=){

        cout<<"初始化失败"<<endl;

        return -;

    }

    s=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);

    if(s==INVALID_SOCKET){

        cout<<"创建socket失败"<<endl;

        return -;

    }

    SOCKADDR_IN addr;

    memset(&addr,,sizeof(addr));

    addr.sin_family=AF_INET;

    addr.sin_addr.S_un.S_addr=htonl(INADDR_ANY);

    addr.sin_port=htons();

    errBind= bind(s,(SOCKADDR*)&addr,sizeof(addr));

    if(errBind!=){

        cout<<"bind failed!"<<endl;

        return -;

    }

    listen(s,);

    SOCKADDR_IN addrClient;

    int len=sizeof(addrClient);

    char *filename="e:\\winSQL.zip";

    while (true)

    {

        SOCKET sockClient=accept(s,(SOCKADDR*)&addrClient,&len);

        //用于发送文件名

         char *sendBuf="winSQL.zip";

        int sendNum= send(sockClient,sendBuf,strlen(sendBuf)+,);

        char sendFileBuf[];

        memset(sendFileBuf,,sizeof(sendFileBuf));

        DWORD dwRead=NULL;

        HANDLE hFile=CreateFile(filename,GENERIC_READ,,,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,);

        while (true)

        {

            if(!ReadFile(hFile,sendFileBuf,,&dwRead,)){

                cout<<"read buf error!"<<endl;

                break;

            }else if(dwRead==)

            {

                cout<<"send over"<<endl;

                break;

            }else

            {

                send(sockClient,sendFileBuf,dwRead,);

            }

        }

        CloseHandle(hFile);

        shutdown(sockClient,SD_BOTH);

        closesocket(sockClient);

    }

    closesocket(s);

    WSACleanup();

    system("pause");

    return ;

}

客户端为接收端：

#include "stdafx.h"

#include <WinSock2.h>

#include <iostream>

using namespace std;

#pragma comment(lib,"ws2_32.lib")

int _tmain(int argc, TCHAR *argv[])

{

   WSADATA wsaData;

   SOCKADDR_IN s;

   int conerr;

    WSAStartup(MAKEWORD(,),&wsaData);

    SOCKET clientSock=socket(AF_INET,SOCK_STREAM,);

    memset(&s,,sizeof(s));

    s.sin_family=AF_INET;

    s.sin_addr.S_un.S_addr=inet_addr("172.18.4.161");

    s.sin_port=htons();

    conerr= connect(clientSock,(SOCKADDR*)&s,sizeof(s));

    if(conerr!=){

        cout<<"connect failed:"<<conerr<<endl;

    }

    //接收文件名，并拼接文件存放路径

    char recBuf[];

    recv(clientSock,recBuf,,);

    char filename[]="c:\\";

    strcat(filename,recBuf);

    cout<<"文件位置"<<filename<<endl;

        char recFileBuf[];

        int numRead;

        DWORD dwWrite;

        DWORD tmp=;

        HANDLE hFile=CreateFile(filename,GENERIC_WRITE,,,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,);

    while (true)

        {

            numRead=recv(clientSock,recFileBuf,,);

            if(numRead==SOCKET_ERROR){

                cout<<"connect error"<<endl;

                break;

            }

            tmp=tmp+numRead;

            if(numRead==){

                cout<<"receive over"<<endl;

                break;

            }

            if(!WriteFile(hFile,recFileBuf,numRead,&dwWrite,)){

                cout<<"write failed!"<<endl;

                break;

            }

        }

    cout<<"共接收："<<tmp<<" 字节"<<endl;

    CloseHandle(hFile);

    system("pause");

   return ;

}