compresing

you can use TCabFile from TMS software or Delphi Zip components from http://www.geocities.com/SiliconValley/Network/2114/index.html

well, i hoped for the "native way" - i mean i do not want to use any zips, rars or something else and i want not to buy something (if it is possible). i would like to build my own unit/component to provide this.

does anybody know the sources of descriptions for this problem? any literatury, when the components are not awailable.

well you can do all the work yourself if you want to
just download the CAB SDK from here :
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dncabsdk/html/cabdl.asp

I'll try to find a free delphi cab wrapper

dont know how 2 use *.cab but i do know how 2 compress files + add them together like winzip heres the comopression part you will need to declare zlib in the USES part!

procedure CompressStream(inpStream, outStream: TStream);
var
 InpBuf,OutBuf: Pointer;
 InpBytes,OutBytes: integer;
begin
 InpBuf := nil;
 OutBuf := nil;
 try
   GetMem(InpBuf,inpStream.size);
   inpStream.Position := 0;
   InpBytes := inpStream.Read(InpBuf^,inpStream.size);
   CompressBuf(InpBuf,InpBytes,OutBuf,OutBytes);
   outStream.Write(OutBuf^,OutBytes);
 finally
   if InpBuf <> nil then FreeMem(InpBuf);
   if OutBuf <> nil then FreeMem(OutBuf);
 end;
end;
procedure DecompressStream(inpStream, outStream: TStream);
var
 InpBuf,OutBuf: Pointer;
 OutBytes,sz: integer;
begin
 InpBuf := nil;
 OutBuf := nil;
 sz := inpStream.size-inpStream.Position;
 if sz > 0 then try
   GetMem(InpBuf,sz);
   inpStream.Read(InpBuf^,sz);
   DecompressBuf(InpBuf,sz,0,OutBuf,OutBytes);
   outStream.Write(OutBuf^,OutBytes);
 finally
   if InpBuf <> nil then FreeMem(InpBuf);
   if OutBuf <> nil then FreeMem(OutBuf);
 end;
 outStream.Position := 0;
end;

well, the cab sdk is the best solution of my needs, so i will accept Lee_Nover's answers.

but i thank for all yours interresting comments!

thanks Lee_Nover!