Pascal (Lazarus/Delphi)

Unzip an AES Encrypted Text File directly into a String Variable

See more Zip Examples

A common need is to unzip from an AES encrypted Zip archive directly into a string variable, such that the unencrypted file never resides on disk, even temporarily. This example shows how to do it. 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.ZipEntry,
  Chilkat.Zip;

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

procedure RunDemo;
var
  success: Boolean;
  zip: TZip;
  entry: TZipEntry;
  lineEndingBehavior: Integer;
  srcCharset: string;
  xmlText: string;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  zip := TZip.Create;

  //  This example opens a WinZip-compatible AES encrypted
  //  .zip that contains a single file: hamlet.xml.

  //  It decrypts and unzips hamlet.xml directly into a string
  //  variable.
  zip.SetPassword('secret');
  success := zip.OpenZip('qa_data/hamlet.zip');
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  entry := TZipEntry.Create;
  success := zip.EntryOf('hamlet.xml',entry);
  if (success = False) then
    begin
      WriteLn(zip.LastErrorText);
      Exit;
    end;

  //  lineEndingBehavior:
  //  0 = leave unchanged.
  //  1 = convert all to bare LF's
  //  2 = convert all to CRLF's
  lineEndingBehavior := 0;
  srcCharset := 'utf-8';
  xmlText := entry.UnzipToString(lineEndingBehavior,srcCharset);
  WriteLn(xmlText);


  zip.Free;
  entry.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.