Re: API for excess DOS file attributes??

[Oleksandr Gavenko <gavenkoa@gmail.com>]

29.09.2011 23:23, Eli Zaretskii пишет:
>> From: Oleksandr Gavenko<gavenkoa@gmail.com>
>> Date: Thu, 29 Sep 2011 22:59:09 +0300
>>
>> So I think that I can not excess to this data from Emacs
>> (native Windows build).
>
> Not from Lisp, no.
>
>> I try rewrite 'follow-cygwin-symlink' from:
>>
>>     http://www.emacswiki.org/emacs/setup-cygwin.el
>>
>> for more strict conformance of definition of symbolic link
>> in Cygwin (from 'cygwin-ug-net-nochunks.html'):
>>
>>     The file style symlinks are files containing a magic cookie
>>     followed by the path to which the link points. They are marked
>>     with the System DOS attribute so that only files with that
>>     attribute have to be read to determine whether or not the file is
>>     a symbolic link.
>
> What's in setup-cygwin.el is about as good as you can get in Lisp.  A
> better solution would be to add to file-symlink-p and
> make-symbolic-link the ability to recognize and create Cygwin-style
> symlink (and Windows 7 style symlink as well), but that requires
> changes on the C level.
>
OK.

I get next new definition of 'follow-cygwin-symlink', which work with
new (to Cygwin 1.7) style of links:

(when (eq windows-system 'w32)

   (defun follow-cygwin-symlink ()
     "Follow new-style (and also UCS-16) Cygwin symlinks."
     (save-excursion
       (goto-char 0)
       (when (looking-at "!<symlink>\xff\xfe")
         (find-alternate-file
          (substring
           (decode-coding-string
            (buffer-substring (match-end 0) (point-max))
            'utf-16-le)
           0 -1)                           ; -1 for stripping final \0.
          ))))
   (add-hook 'find-file-hooks 'follow-cygwin-symlink)

  )

I don't incorporate it back to emacswiki as don't understand some part
of old code.

Maintainer of this file is Drew Adams, but I don't know how contact
with him.