Delphi ActiveX

Send an FTP NOOP (Keep-Alive)

Demonstrates the Chilkat Ftp2.Noop method, which sends the FTP NOOP command. It takes no arguments and succeeds only when the server returns a positive reply.

Background: NOOP asks the server to do nothing and simply reply, which makes it the standard keep-alive: sending one periodically resets the server's idle timer so a long-running job does not lose its control connection between transfers. Because it exercises a real request/reply round trip, a successful NOOP is also firmer evidence the connection is alive than CheckConnection.

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var
success: Integer;
ftp: TChilkatFtp2;

begin
success := 0;

//  Demonstrates the Ftp2.Noop method, which sends the FTP NOOP command.  It takes no arguments.
//  The server must return a positive reply for the method to succeed.

ftp := TChilkatFtp2.Create(Self);

ftp.Hostname := 'ftp.example.com';
ftp.Username := 'myFtpLogin';

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
ftp.Password := 'myPassword';

//  Connect and log in (Connect performs both).
success := ftp.Connect();
if (success = 0) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;

//  NOOP does nothing on the server, but a successful reply confirms the control connection is
//  still responsive -- useful as a keep-alive during an otherwise idle session.
success := ftp.Noop();
if (success = 0) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('NOOP acknowledged by the server.');

success := ftp.Disconnect();
if (success = 0) then
  begin
    Memo1.Lines.Add(ftp.LastErrorText);
    Exit;
  end;