Pascal (Lazarus/Delphi)

Append Files to an Existing ZIP Archive Using QuickAppend

See more Zip Examples

Demonstrates how to use the QuickAppend method to append additional files to an existing ZIP archive.

Unlike methods that rewrite the entire ZIP archive, QuickAppend modifies the existing ZIP in-place by appending new entries directly to the end of the archive.

Existing ZIP entries are not recompressed or rewritten, making QuickAppend the fastest and most efficient way to add files to a large pre-existing ZIP archive.

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.Zip;

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

procedure RunDemo;
var
  success: Boolean;
  zip: TZip;
  saveExtraPath: Boolean;

begin
  success := False;

  zip := TZip.Create;

  //  ------------------------------------------------------------
  //  Initialize a new Zip object.
  //  
  //  NewZip resets the Zip object to a new and empty state.
  //  It does NOT immediately create or write a .zip file.
  //  
  //  The filename passed to NewZip is not used by QuickAppend,
  //  but NewZip is still useful because it initializes the
  //  Zip object to an empty state.
  success := zip.NewZip('notUsed.zip');
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  //  ------------------------------------------------------------
  //  Add a reference to a local filesystem file.
  //  
  //  AddFile does NOT immediately read or compress the file.
  //  Instead, it adds a reference to the file that will later
  //  be processed when QuickAppend is called.
  //  
  //  The file being referenced is:
  //  
  //      c:/temp/files/something.dat
  //  
  saveExtraPath := False;

  success := zip.AddFile('c:/temp/files/something.dat',saveExtraPath);

  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  //  Because saveExtraPath = False,
  //  the file will be stored in the ZIP as:
  //  
  //      something.dat
  //  

  //  ------------------------------------------------------------
  //  Append the referenced files to an existing ZIP archive.
  //  
  //  QuickAppend opens the existing ZIP archive:
  //  
  //      c:/temp/zips/preExisting.zip
  //  
  //  The referenced files are then:
  //  
  //    * Read from the local filesystem
  //    * Compressed as needed
  //    * Appended to the existing ZIP archive
  //  
  success := zip.QuickAppend('c:/temp/zips/preExisting.zip');
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  WriteLn('Files appended successfully.');
  WriteLn('');

  //  ------------------------------------------------------------
  //  Additional files, directory trees, or in-memory data
  //  can be added before calling QuickAppend.
  //  
  //  For example:
  //  
  //      AddFile
  //      AppendFiles
  //      AppendFilesEx
  //      AddString
  //      AddBd
  //      AddSb
  //  
  //  Whatever entries are currently referenced by the Zip object
  //  are appended to the existing ZIP archive when QuickAppend
  //  is called.


  zip.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.