Pascal (Lazarus/Delphi)

Set a Custom Last-Modified Date in a Gzip File

See more Gzip Examples

This example demonstrates how to use the SetDt method to specify a custom last-modified date and time that will be embedded in a Gzip file.

A CkDateTime object is first initialized with a specific date/time using an RFC 822 formatted string. This date/time is then applied to the Gzip object using SetDt.

When a compression method is called (such as CompressStringToFile), the specified date/time is included in the Gzip metadata. This allows the resulting .gz file to carry a meaningful timestamp rather than using the current system time.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.CkDateTime,
  Chilkat.Gzip;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  gzip: TGzip;
  dt: TCkDateTime;
  inputStr: string;

begin
  success := False;

  //  This example demonstrates how to set a custom last-modified date/time
  //  that will be embedded in a Gzip file.

  gzip := TGzip.Create;
  dt := TCkDateTime.Create;

  //  Set the date/time using a timestamp format (ISO 8601 style):
  dt.SetFromTimestamp('2025-11-15T12:45:26-05:00');

  //  Apply the date/time to the Gzip object:
  success := gzip.SetDt(dt);
  if (success = False) then
    begin
      WriteLn(gzip.LastErrorText);
      Exit;
    end;

  //  Compress a string so the custom date/time is embedded in the .gz:
  inputStr := 'Example text for Gzip compression.';
  success := gzip.CompressStringToFile(inputStr,'utf-8','output.gz');
  if (success = False) then
    begin
      WriteLn(gzip.LastErrorText);
      Exit;
    end;

  WriteLn('Gzip file created with custom last-modified date.');


  gzip.Free;
  dt.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.