i := Length(Str);
    while (i > 0) and (Str[i] = ' ') do
        i := i - 1;
    Result := Copy(Str, 1, i);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TrimLeft(Str : String) : String;
var
    i : Integer;
begin
    if Str[1] <> ' ' then
        Result := Str
    else begin
        i := 1;
        while (i <= Length(Str)) and (Str[i] = ' ') do
            i := i + 1;
        Result := Copy(Str, i, Length(Str) - i + 1);
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function Trim(Str : String) : String;
begin
    Result := TrimLeft(TrimRight(Str));
end;
{$ENDIF}


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function GetFileSize(FileName : String) : LongInt;
var
    SR : TSearchRec;
begin
    if FindFirst(FileName, faReadOnly or faHidden or
                 faSysFile or faArchive, SR) = 0 then
        Result := SR.Size
    else
        Result := -1;
    FindClose(SR);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
constructor TFtpServer.Create(AOwner: TComponent);
begin
    inherited Create(AOwner);
    FWindowHandle    := AllocateHWnd(WndProc);
    FServSocket      := TWSocket.Create(Self);
    FServSocket.Name := 'ServerWSocket';
    FClientList      := TList.Create;
    FPort            := 'ftp';
    FAddr            := '0.0.0.0';
    FBanner          := msgDftBanner;
    FClientClass     := TFtpCtrlSocket;
    AddCommand('PORT', CommandPORT);
    AddCommand('STOR', CommandSTOR);
    AddCommand('RETR', CommandRETR);
    AddCommand('CWD',  CommandCWD);
    AddCommand('XPWD', CommandXPWD);
    AddCommand('PWD',  CommandPWD);
    AddCommand('USER', CommandUSER);
    AddCommand('PASS', CommandPASS);
    AddCommand('LIST', CommandLIST);
    AddCommand('NLST', CommandNLST);
    AddCommand('TYPE', CommandTYPE);
    AddCommand('SYST', CommandSYST);
    AddCommand('QUIT', CommandQUIT);
    AddCommand('DELE', CommandDELE);
    AddCommand('SIZE', CommandSIZE);
    AddCommand('REST', CommandREST);
    AddCommand('RNFR', CommandRNFR);
    AddCommand('RNTO', CommandRNTO);
    AddCommand('MKD',  CommandMKD);
    AddCommand('RMD',  CommandRMD);
    AddCommand('ABOR', CommandABOR);
    AddCommand('PASV', CommandPASV);
    AddCommand('NOOP', CommandNOOP);
    AddCommand('CDUP', CommandCDUP);
    AddCommand('APPE', CommandAPPE);
    AddCommand('STRU', CommandSTRU);
    AddCommand('XMKD', CommandMKD);
    AddCommand('XRMD', CommandRMD);
    AddCommand('MDTM', CommandMDTM);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
destructor TFtpServer.Destroy;
begin
    if Assigned(FServSocket) then begin
        FServSocket.Destroy;
        FServSocket := nil;
    end;
    if Assigned(FClientList) then begin
        FClientList.Destroy;
        FClientList := nil;
    end;
    DeallocateHWnd(FWindowHandle);
    inherited Destroy;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.WndProc(var MsgRec: TMessage);
begin
    with MsgRec do begin
        case Msg of
        WM_FTPSRV_CLOSE_REQUEST  : WMFtpSrvCloseRequest(MsgRec);
        WM_FTPSRV_CLIENT_CLOSED  : WMFtpSrvClientClosed(MsgRec);
        WM_FTPSRV_ABORT_TRANSFER : WMFtpSrvAbortTransfer(MsgRec);
        WM_FTPSRV_CLOSE_DATA     : WMFtpSrvCloseData(MsgRec);
        else
            Result := DefWindowProc(Handle, Msg, wParam, lParam);
        end;
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.WMFtpSrvCloseRequest(var msg: TMessage);
var
    Client : TFtpCtrlSocket;
begin
    Client := TFtpCtrlSocket(msg.LParam);
    if Client.AllSent then
        Client.Close
    else
        Client.CloseRequest := TRUE;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.Notification(AComponent: TComponent; operation: TOperation);
begin
    inherited Notification(AComponent, operation);
    if operation = opRemove then begin
        if AComponent = FServSocket then
            FServSocket := nil;
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.AddCommand(
    const Keyword : String;
    const Proc    : TFtpSrvCommandProc);
begin
    if FLastCmd > High(FCmdTable) then
        raise FtpServerException.Create('Too many command');
    FCmdTable[FLastCmd].KeyWord := KeyWord;
    FCmdTable[FLastCmd].Proc    := Proc;
    Inc(FLastCmd);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.Start;
begin
    if FServSocket.State = wsListening then
        Exit;             { Server is already running }
    FServSocket.Port  := Port;
    FServSocket.Proto := 'tcp';
    FServSocket.Addr  := FAddr;
    FServSocket.OnSessionAvailable := ServSocketSessionAvailable;
    FServSocket.OnChangeState      := ServSocketStateChange;
    FServSocket.Listen;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.Stop;
begin
    FServSocket.Close;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.DisconnectAll;
var
    Client : TFtpCtrlSocket;
begin
    while FClientList.Count > 0 do begin
        Client := TFtpCtrlSocket(FClientList.Items[0]);
        Client.Close;
        FClientList.Remove(Client);
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
function TFtpServer.GetActive : Boolean;
begin
    Result := (FServSocket.State = wsListening);
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.SetActive(newValue : Boolean);
begin
    if newValue then
        Start
    else
        Stop;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.ServSocketStateChange(Sender : TObject; OldState, NewState : TSocketState);
begin
    if csDestroying in ComponentState then
        Exit;
    if NewState = wsListening then
        TriggerServerStart
    else if NewState = wsClosed then
        TriggerServerStop;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.ServSocketSessionAvailable(Sender : TObject; Error : Word);
var
    Client : TFtpCtrlSocket;
begin
    if Error <> 0 then
        raise FtpServerException.Create('Session available error #' + IntToStr(Error));
    Inc(FClientNum);
    Client                 := FClientClass.Create(Self);
    FClientList.Add(Client);
    Client.Name            := 'ClientWSocket' + IntToStr(FClientNum);
    Client.DataSocket.Name := 'DataWSocket' + IntToStr(FClientNum);
    Client.Banner          := FBanner;
    Client.HSocket         := ServSocket.Accept;
    Client.OnCommand       := ClientCommand;
    Client.OnSessionClosed := ClientSessionClosed;
    Client.OnDataSent      := ClientDataSent;
    TriggerClientConnect(Client, Error);
    { The event handler may have destroyed the client ! }
    if FClientList.IndexOf(Client) < 0 then
        Exit;
    { The event handler may have closed the connection }
    if Client.State <> wsConnected then
        Exit;
    { Ok, the client is still there, process with the connection }
    if (FMaxClients > 0) and (FMaxClients < ClientCount) then begin
        { Sorry, toomuch clients }
        Client.Banner := msgTooMuchClients;
        Client.StartConnection;
        Client.Close;
    end
    else
        Client.StartConnection;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.SendAnswer(Client : TFtpCtrlSocket; Answer : TFtpString);
begin
    try
        TriggerSendAnswer(Client, Answer);
        Client.SendAnswer(Answer);
    except
        { Just ignore any exception here }
    end;
end;


{* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *}
procedure TFtpServer.ClientCommand(
    Sender : TObject;
    CmdBuf : PChar;
    CmdLen : Integer);
const
    TELNET_IAC       = #255;
    TELNET_IP        = #244;
    TELNET_DATA_MARK = #242;
var
    Client  : TFtpCtrlSocket;
    Answer  : TFtpString;
    Params  : TFtpString;
    KeyWord : TFtpString;
    I, J    : Integer;
begin
    Client := Sender as TFtpCtrlSocket;
    Answer := '';

    { Copy the command received, removing any telnet option }
    try
        Params := '';
        I      := 0;
        while I < CmdLen do begin
            if CmdBuf[I] <> TELNET_IAC then begin
                Params := Params + CmdBuf[I];
                Inc(I);
            end
            else begin
                Inc(I);
                if CmdBuf[I] = TELNET_IAC then
                    Params := Params + CmdBuf[I];
                Inc(I);
            end;
        end;

        { Extract keyword, ignoring leading spaces and tabs }
        I := 1;
        while (I <= Length(Params)) and (Params[I] in [' ', #9]) do