[fpc-pascal] TZipper and special file names like "atenção.txt" (#26213)

[silvioprog]

2014-05-23 15:50 GMT-03:00 Craig Peterson <craig at scootersoftware.com>:

> > Nice. I can do it, opening a new issue in bugtracker.
>
> Filename encoding in zip files is poorly defined.  The current
> APPNOTE.txt says that the only valid encoding is OEM 437, with UTF-8 if
> a bit is set in the header, but those were recent additions, and in
> practice Windows applications will generally use either the OEM or ANSI
> codepage of the current system locale, and files generated on Unix will
> be UTF-8 but won't have the language encoding bit set.
>
> Abbrevia's zip encoding/decoding tries to handle the issue in as
> compatible a manner as possible.  It stores the original filenames as
> OEM/ANSI based on the current system, and stores a UTF-8 copy in an
> extended header so there's a known way to decode it when changing
> locales.  When reading it has to use lookup tables to guess if the
> filenames are likely OEM or ANSI.  On Unicode-enabled Delphi releases
> it's fully Unicode enabled; on FreePascal and older Delphi releases it
> only supports ANSI filenames but still does proper encoding/decoding.
>
> The relevant code is in AbZipTyp.pas in TAbZipItem.SetFilename and
> TAbZipItem.LoadFromStream if you want a reference.  It's under the MPL,
> but I'm the original author and I'm happy to relicense it if someone
> else wants to incorporate the code into paszlib.
>
>
> https://sourceforge.net/p/tpabbrevia/code/HEAD/tree/trunk/source/AbZipTyp.pas
>
> --
> Craig Peterson
> Scooter Software


Very nice.

I have a question. Adding this extended header, can I open/uncompress the
zip file normally in programs like 7z and WinRAR?

-- 
Silvio Clécio
My public projects - github.com/silvioprog
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freepascal.org/pipermail/fpc-pascal/attachments/20140523/85f9b160/attachment.html>