Lazarus 7zip

Create archives, extract files from archive, list files inside archives - using 7-zip DLL version 21.07.

Library by Henri Gourvest updated to newer 7-zip.

Version 1.3

About

This API use the 7-zip dll (7z.dll) to read and write all 7-zip supported archive formats. According to the documentation, file formats listed below are supported, although many may only support decompression/extraction and not creation/compression.

• zip
• bz2
• rar
• arj
• z
• lzh
• 7z
• cab
• nsis
• lzma
• lzma86
• xz
• ppmd
• squashFS
• cramFS
• apm
• mslz
• flv
• swf
• swfc
• ntfs
• fat
• mbr
• vhd
• pe
• elf
• macho
• udf
• xar
• mub
• hfs
• dmg
• compound doc
• wim
• iso
• bkf
• chm
• split
• rpm
• deb
• cpio
• tar
• gzip

Detecting format

var i: Integer;
    Guid: TGuid;
    Filename: String;
begin
  if not OpenDialog1.Execute then Exit;

  Filename := OpenDialog1.Filename;

  Guid := DetectFormat(Filename);
  if IsEqualGUID(Guid, CLSID_CFormat_Unsupported) then begin
    ShowMessage('Unsupported');
    Exit;
  end;

  with CreateInArchive(Guid) do begin
   OpenFile(Filename);
   for i := 0 to NumberOfItems - 1 do
    if not ItemIsFolder[i] then
      Memo1.Lines.Add(
        ItemPath[i] + ' == ' + GetItemCRC(i) +
        ItemComment[i] +IntToStr(GetItemPackSize(i)) + ' ' +
        FormatDateTime('YYYY-MM-DD', GetItemModDate(i))
        );
  end;

Reading archive:

Extract to path:

 with CreateInArchive(CLSID_CFormatZip) do
 begin
   OpenFile('c:\test.zip');
   ExtractTo('c:\test');
 end;

Get file list:

 with CreateInArchive(CLSID_CFormat7z) do
 begin
   OpenFile('c:\test.7z');
   for i := 0 to NumberOfItems - 1 do
    if not ItemIsFolder[i] then
      Writeln(ItemPath[i]);
 end;

Extract to stream

 with CreateInArchive(CLSID_CFormat7z) do
 begin
   OpenFile('c:\test.7z');
   for i := 0 to NumberOfItems - 1 do
     if not ItemIsFolder[i] then
       ExtractItem(i, stream, false);
 end;

Extract "n" Items

function GetStreamCallBack(sender: Pointer; index: Cardinal;
  var outStream: ISequentialOutStream): HRESULT; stdcall;
begin
  case index of ...
    outStream := T7zStream.Create(aStream, soReference);
  Result := S_OK;
end;

procedure TMainForm.ExtractClick(Sender: TObject);
var
  i: integer;
  items: array[0..2] of Cardinal;
begin
  with CreateInArchive(CLSID_CFormat7z) do
  begin
    OpenFile('c:\test.7z');
    // items must be sorted by index!
    items[0] := 0;
    items[1] := 1;
    items[2] := 2;
    ExtractItems(@items, Length(items), false, nil, GetStreamCallBack);
  end;
end;

Open stream

 with CreateInArchive(CLSID_CFormatZip) do
 begin
   OpenStream(T7zStream.Create(TFileStream.Create('c:\test.zip', fmOpenRead), soOwned));
   OpenStream(aStream, soReference);
   ...
 end;

Progress bar

 function ProgressCallback(sender: Pointer; total: boolean; value: int64): HRESULT; stdcall;
 begin
   if total then
     Mainform.ProgressBar.Max := value else
     Mainform.ProgressBar.Position := value;
   Result := S_OK;
 end;

 procedure TMainForm.ExtractClick(Sender: TObject);
 begin
   with CreateInArchive(CLSID_CFormatZip) do
   begin
     OpenFile('c:\test.zip');
     SetProgressCallback(nil, ProgressCallback);
     ...
   end;
 end;

Password

 function PasswordCallback(sender: Pointer; var password: WideString): HRESULT; stdcall;
 begin
   // call a dialog box ...
   password := 'password';
   Result := S_OK;
 end;

 procedure TMainForm.ExtractClick(Sender: TObject);
 begin
   with CreateInArchive(CLSID_CFormatZip) do
   begin
     // using callback
     SetPasswordCallback(nil, PasswordCallback);
     // or setting password directly
     SetPassword('password');
     OpenFile('c:\test.zip');
     ...
   end;
 end;

Writing archive

 procedure TMainForm.ExtractAllClick(Sender: TObject);
 var
   Arch: I7zOutArchive;
 begin
   Arch := CreateOutArchive(CLSID_CFormat7z);
   // add a file
   Arch.AddFile('c:\test.bin', 'folder\test.bin');
   // add files using willcards and recursive search
   Arch.AddFiles('c:\test', 'folder', '*.pas;*.dfm', true);
   // add a stream
   Arch.AddStream(aStream, soReference, faArchive, CurrentFileTime, CurrentFileTime, 'folder\test.bin', false, false);
   // compression level
   SetCompressionLevel(Arch, 5);
   // compression method if <> LZMA
   SevenZipSetCompressionMethod(Arch, m7BZip2);
   // add a progress bar ...
   Arch.SetProgressCallback(...);
   // set a password if necessary
   Arch.SetPassword('password');
   // Save to file
   Arch.SaveToFile('c:\test.zip');
   // or a stream
   Arch.SaveToStream(aStream);
 end;