Delphi DLL

Close a Remote SFTP File or Directory Handle

Demonstrates the Chilkat SFtp.CloseHandle method, which closes a remote file or directory handle previously returned by OpenFile or OpenDir. The only argument is the handle.

Background: Every opened handle corresponds to state the server holds, and servers cap how many a session may keep open at once, so a long-running program that forgets to close handles will eventually start failing to open new ones. Closing also ensures buffered writes are committed. Once closed, a handle is invalid and must not be reused.

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var
success: Boolean;
sftp: HCkSFtp;
port: Integer;
password: PWideChar;
handle: PWideChar;

begin
success := False;

//  Demonstrates the SFtp.CloseHandle method, which closes a remote file or directory handle.  The
//  only argument is the handle returned by OpenFile or OpenDir.

sftp := CkSFtp_Create();

//  Connect, authenticate, and initialize the SFTP subsystem.
port := 22;
success := CkSFtp_Connect(sftp,'sftp.example.com',port);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSFtp__lastErrorText(sftp));
    Exit;
  end;

//  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.
password := 'mySshPassword';

success := CkSFtp_AuthenticatePw(sftp,'mySshLogin',password);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSFtp__lastErrorText(sftp));
    Exit;
  end;

success := CkSFtp_InitializeSftp(sftp);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSFtp__lastErrorText(sftp));
    Exit;
  end;

//  Open a remote file, obtaining a handle.
handle := CkSFtp__openFile(sftp,'subdir/data.txt','readOnly','openExisting');
if (CkSFtp_getLastMethodSuccess(sftp) = False) then
  begin
    Memo1.Lines.Add(CkSFtp__lastErrorText(sftp));
    Exit;
  end;

//  ... use the handle ...

//  Close the handle to release the server-side resource.  A handle should not be used after it
//  is closed.
success := CkSFtp_CloseHandle(sftp,handle);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSFtp__lastErrorText(sftp));
    Exit;
  end;
Memo1.Lines.Add('Handle closed.');

CkSFtp_Disconnect(sftp);

CkSFtp_Dispose(sftp);