TCP文件发送

发送端（客户端）

 #include <iostream>
 #include <winsock2.h>
 #include <Ws2tcpip.h>
 #include <fstream>
 using namespace std;

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

 struct FileHeader
 {

     char m_szFileName[MAX_PATH];//windows下，全文件名的字符长度是有限制的，众所周知，是MAX_PATH，260
     int  m_nFileSize;

 };

 int main()
 {
      WORD wVersionRequested;
     WSADATA wsaData;
     int err;

     wVersionRequested = MAKEWORD(, );

     err = WSAStartup(wVersionRequested, &wsaData);
     if (err != ) {

         printf("WSAStartup failed with error: %d\n", err);
         return ;
     }

     if (LOBYTE(wsaData.wVersion) !=  || HIBYTE(wsaData.wVersion) != ) {

         printf("Could not find a usable version of Winsock.dll\n");
         WSACleanup();
         return ;
     }
     else
         printf("The Winsock 2.2 dll was found okay\n");

     SOCKET sockClient = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
     if(INVALID_SOCKET == sockClient)
     {
          WSACleanup();
         return ;
     }
     cout<<"请输入服务器iP"<<endl;
     char szip[] = {};
     cin>>szip;
     sockaddr_in  addr;

 addr.sin_addr.S_un.S_addr=inet_addr("192.168.202.1");

     addr.sin_family = AF_INET;
     //addr.sin_addr.S_un.S_addr = inet_addr("192.168.1.251");
     addr.sin_port = htons();

     if(SOCKET_ERROR ==    connect(sockClient,(const sockaddr*)&addr,sizeof(addr)))
     {
          WSACleanup();
          closesocket(sockClient);
         return ;
     }

     char szFilePath[MAX_PATH] = {};
     char *ptemp = szFilePath;
     char szResult[] = {};//是，否
     char szContent[] = {};//文件内容
     //文件头
     //文件名，文件大小
     FileHeader fh;
     cout<<"请输入要传输的文件"<<endl;
     cin>>szFilePath;

     //获得文件名
     while(*ptemp++ != '\0');
     while(*(--ptemp) != '\\');//\\是一个字符
     ptemp++;

     strcpy_s(fh.m_szFileName,MAX_PATH,ptemp);

     fstream fs;
     fs.open(szFilePath,fstream::in|fstream::binary);//以二进制流的方式读入，中间是'|'

     fs.seekg(,fstream::end);//使文件指针偏移到末尾，用法详细可以见：
     fh.m_nFileSize = fs.tellg();  //获得文件指针所在位置的文件大小
     fs.seekg(,fstream::beg);//将文件指针偏移位置置回0
     //发送，先发送文件的基本信息
     send(sockClient,(const char*)&fh,sizeof(fh),);

     //等待对方回复
     recv(sockClient,szResult,sizeof(szResult),);

     if( == strcmp(szResult,"是"))
     {
         //如果是肯定回复

         while()
         {
           //读文件
             fs.read(szContent,sizeof(szContent));
             int nRelReadNum = fs.gcount();
             if(nRelReadNum == )
             {
                 break;
             }
             //发文件
             send(sockClient,szContent,nRelReadNum,);
         }

     }
     //关闭文件
     fs.close();
     closesocket(sockClient);
     WSACleanup();
     system("pause");
     return ;
 }

接收端（服务器）

 #include<stdio.h>
 #include<iostream>
 #include<fstream>
 #include<winsock2.h>
 #pragma comment(lib,"ws2_32.lib")
 using namespace std;
 struct fileFifo
 {
     char fileName[MAX_PATH];
     int fileSize;
 };
 int main()
 {
     //初始化wsa
     WORD wVersionRequested;
     WSADATA wsaData;
     int err;
     wVersionRequested = MAKEWORD(, );

     err = WSAStartup(wVersionRequested, &wsaData);
     if (err != )
     {

         printf("WSAStartup failed with error: %d\n", err);
         return ;
     }

     if (LOBYTE(wsaData.wVersion) !=  || HIBYTE(wsaData.wVersion) != )
     {

         printf("Could not find a usable version of Winsock.dll\n");
         WSACleanup();
         return ;
     }
     else
         printf("The Winsock 2.2 dll was found okay\n");

     SOCKET sever;
     SOCKET waiter;
     struct sockaddr_in severaddr;
     struct sockaddr_in clientaddr;
     char recvbuf[];//接受缓冲区
     char sendbuf[];//发送缓冲区
     //创建套接字
     sever=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
     if(sever==INVALID_SOCKET)
     {
         WSACleanup();
         return ;
     }
     /*if(sever=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP)==INVALID_SOCKET)
     {
         WSACleanup();
         return 1;
     }*/
     //绑定
     severaddr.sin_family=AF_INET;
     severaddr.sin_port=htons();
     severaddr.sin_addr.S_un.S_addr=inet_addr("192.168.202.1");

     if(bind(sever,(const sockaddr*)&severaddr,sizeof(severaddr))==SOCKET_ERROR)
     {
         WSACleanup();
         closesocket(sever);
         return ;
     }
     if(listen(sever,)==SOCKET_ERROR)
     {
         WSACleanup();
         return ;
     }
     printf("等待连接...\n");
     int clientlen=sizeof(clientaddr);
     waiter=accept(sever,(SOCKADDR*)&clientaddr,&clientlen);
     if(waiter==INVALID_SOCKET)//第一个参数为监听套接字
     {
         printf("接受失败\n");
         WSACleanup();
         closesocket(sever);
         return ;
     }
     char filePath[MAX_PATH];
     char result[]={};
     char context[];
     fileFifo file;
     fstream fs;
     recv(waiter,(char *)&file,sizeof(file),);//发送的和接受的数据类型要一致

     cout<<"文件大小为："<<file.fileSize<<endl;
     cout<<"请输入是否接受该文件"<<endl;
     cin>>result;
     int tempsize=file.fileSize;

     send(waiter,result,sizeof(result),);

     if(strcmp(result,"是")==)
     {
         cout<<"您要存储得路径为："<<endl;
         cin>>filePath;
         strcat_s(filePath,MAX_PATH,file.fileName);
         //对应路径下创建文件用于接受
         fs.open(filePath,fstream::binary|fstream::out|fstream::trunc);
         while(tempsize)
         {
             //接收文件内容
             int numRecv=recv(waiter,context,sizeof(context),);
             //写文件
             if(numRecv>)
             {
                 tempsize-=numRecv;
                 fs.write(context,numRecv);
             }
         }
     }
     fs.close();
     WSACleanup();
     closesocket(sever);
     closesocket(waiter);
     system("pause");
     return ;
 }