Delphi DLL

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: Boolean;
ftp: HCkFtp2;

begin
success := False;

//  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 := CkFtp2_Create();

CkFtp2_putHostname(ftp,'ftp.example.com');
CkFtp2_putUsername(ftp,'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.
CkFtp2_putPassword(ftp,'myPassword');

//  Connect and log in (Connect performs both).
success := CkFtp2_Connect(ftp);
if (success = False) then
  begin
    Memo1.Lines.Add(CkFtp2__lastErrorText(ftp));
    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 := CkFtp2_Noop(ftp);
if (success = False) then
  begin
    Memo1.Lines.Add(CkFtp2__lastErrorText(ftp));
    Exit;
  end;
Memo1.Lines.Add('NOOP acknowledged by the server.');

success := CkFtp2_Disconnect(ftp);
if (success = False) then
  begin
    Memo1.Lines.Add(CkFtp2__lastErrorText(ftp));
    Exit;
  end;

CkFtp2_Dispose(ftp);