Cygwin 3.7 wishlist: read/write NTFS alternate data streams via openat(O_XATTR)

[Martin Wege]

On Mon, Mar 24, 2025 at 5:00 PM Corinna Vinschen
<corinna-cygwin@cygwin.com> wrote:
>
> Redirected to cygwin-developers
>
> ----- Forwarded message from Martin Wege via Cygwin <cygwin@cygwin.com> -----
>
> > Date: Mon, 24 Mar 2025 15:25:46 +0100
> > From: Martin Wege via Cygwin <cygwin@cygwin.com>
> > Subject: Cygwin 3.7 wishlist: read/write NTFS alternate data streams via
> >       openat(O_XATTR)
> > To: cygwin@cygwin.com
> > Reply-To: Martin Wege <martin.l.wege@gmail.com>
> >
> > Hello,
> >
> > another wishlist entry (old one):
> > read/write NTFS alternate data streams via openat(O_XATTR)
> >
> > Opening individual streams might be easy, as Corinna pointed out that
> > cygwin_attach_handle_to_fd() can be used for that (i.e. open stream,
> > and attach handle to fd via cygwin_attach_handle_to_fd()), but the
> > virtual XATTR dir might be a challenge (beyond my skill at least).
> >

Does the Windows API have an indicator when enumerating directory
entries whether a file has alternate data streams (ADS)?

Thanks,
Martin