Utilize reparse points for symlinks

[Andy Koppe]

On 25 September 2010 19:31, Corinna Vinschen wrote:
>> Anyways, a few more questions about these reparse
>> points:
>>
>> How do they appear in Explorer? What happens if you try to open one?
>> Is Explorer able to delete them? (Just wondering what complaints to
>> expect.)
>
> They appear as normal files of size 0 in explorer.  If you try to
> open one, the "open with" dialog appears.  Since they are normal
> files, explorer can delete them.

Good.

>> Is there a useful error message when trying to execute one from cmd?
>> (C:\cygwin\bin\gcc is particularly popular for that. The current
>> format results in "Access is denied", which isn't great).
>
> I get this:
>
>  "'foo' is not recognized as an internal or external command,
>  operable program or batch file.

Sounds like an improvement.

>> Finally, would it be possible to write a system-wide handler for these
>> reparse points that would make them transparent to all non-Cygwin
>> programs?
>
> In theory you could write a filesystem minifilter using the IFS kit
> from WDK.  However, the file contains POSIX-specific info which makes
> no sense from the Win32 POV.  What is the filter supposed to do?
> Searching for a Cygwin DLL and loading it?  Seaching for a fstab file
> and trying to evaluate the path by itself?

The latter, I guess, whereby ideally it would only do the fstab
loading once. But yep, that's theoretical only. Still, good that it
could be done.

Andy