Winsock Downloader

program FileDown;

uses

  Windows, Winsock, ShellApi;

function GetIpFromDns(HostName: string): string;

type

  tAddr = array[0..100] of PInAddr;

  pAddr = ^tAddr;

var

  I: Integer;

  WSA: TWSAData;

  PHE: PHostEnt;

  P: pAddr;

begin

  Result := HostName;

  WSAStartUp($101, WSA);

  try

    PHE := GetHostByName(pChar(HostName));

    if (PHE <> nil) then

    begin

      P := pAddr(PHE^.h_addr_list);

      I := 0;

      while (P^[i] <> nil) do

      begin

        Result := (inet_nToa(P^[i]^));

        Inc(I);

      end;

    end;

  except

  end;

  WSACleanUp;

end;

procedure GetFile(CompleteURL, SaveToDirectory: string; Puerto: Integer = 80);

var

  WSA: TWSAData;

  DownloaderSocket: TSocket;

  DownloaderAddr: TSockAddrIn;

  SendBuffer: string;

  SentBytes: Integer;

  ReceiveBuffer: array[0..4096] of Char;

  ReceivedBytes: Integer;

  WrittenBytes: Dword;

  HeaderPos: integer;

  Header: string;

  GotHeader: Boolean;

  DownloadedFile: THandle;

  DNS, RemoteFilePath, FileName: string;

  i: integer;

begin

  SentBytes := 0;

  GotHeader := False;

  DNS := Copy(CompleteURL, Pos('http://', CompleteURL) + 7, Length(CompleteURL));

  RemoteFilePath := Copy(DNS, Pos('/', DNS), Length(DNS));

  DNS := Copy(DNS, 1, Pos('/', DNS) - 1);

  i := Length(RemoteFilePath);

  while (RemoteFilePath[i] <> '/') do

  begin

    FileName := RemoteFilePath[i] + FileName;

    Dec(i);

  end;

  WSAStartup($101, WSA);

  DownloaderSocket := Socket(AF_INET, SOCK_STREAM, 0);

  DownloaderAddr.sin_family := AF_INET;

  if (Puerto < 1) or (Puerto > 65535) then Puerto := 80;

  DownloaderAddr.sin_port := htons(Puerto);

  DownloaderAddr.sin_addr.S_addr := inet_addr(PChar(GetIPfromDNS(PChar(DNS))));

  repeat

    if Connect(DownloaderSocket, DownloaderAddr, sizeof(DownloaderAddr)) = 0 then

    begin

      SendBuffer := 'GET ' + RemoteFilePath + ' HTTP/1.1' + #13#10 +

        'Accept: */*' + #13#10 +

        'Accept-Language: en-us;q=0.5' + #13#10 +

        'User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)' + #13#10 +

        'Host: ' + DNS + #13#10 +

        'Connection: close' + #13#10#13#10;

      repeat

        SentBytes := Send(DownloaderSocket, SendBuffer[1 + SentBytes], Length(SendBuffer) - SentBytes, 0);

      until SentBytes >= Length(SendBuffer);

      DownloadedFile := CreateFile(PChar(SaveToDirectory + FileName), GENERIC_WRITE, FILE_SHARE_WRITE, nil, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);

      SetFilePointer(DownloadedFile, 0, nil, FILE_END);

      repeat

        ZeroMemory(@ReceiveBuffer, Sizeof(ReceiveBuffer));

        ReceivedBytes := Recv(DownloaderSocket, ReceiveBuffer, Sizeof(ReceiveBuffer), 0);

        if ReceivedBytes > 0 then

        begin

          case GotHeader of

            False:

              begin

                HeaderPos := Pos(#13#10#13#10, string(ReceiveBuffer));

                if HeaderPos > 0 then

                begin

                  WriteFile(DownloadedFile, ReceiveBuffer[HeaderPos + 3], ReceivedBytes - (HeaderPos + 3), WrittenBytes, nil);

                  SetLength(Header, HeaderPos);

                  Move(ReceiveBuffer[0], Header[1], HeaderPos + 3);

                  GotHeader := True;

                end;

              end;

          else

            WriteFile(DownloadedFile, ReceiveBuffer, ReceivedBytes, WrittenBytes, nil);

          end;

        end;

      until (ReceivedBytes <= 0);

      CloseHandle(DownloadedFile);

      CloseSocket(DownloaderSocket);

      Break;

    end;

    Sleep(60000);

  until False;

  WSACleanup();

  ShellExecute(GetForegroundWindow, 'open', PChar(SaveToDirectory + FileName), '', '', SW_SHOWNORMAL);

end;

begin

  GetFile('http://www.google.co.za/intl/en_com/images/srpr/logo1w.png', 'c:\');

end.