Cygwin and NTFS Junction Points

Frank-Michael Moser moser@decodon.com
Thu Aug 4 10:44:00 GMT 2005


Corinna,

I understand your objections but I think this all could be seen from an
alternate point of view.

As you said, JPs, as they are implemented, are less useful than real
POSIX symlinks. Now instead of miming Microsofts intention with the JPs,
why not simply considering them consequently as symlinks in Cygwin and
so making them really useful, at least for Cygwin users. This could be
competed by installing NTFSLink and so getting JPs consequently and
transparently handled as POSIX-like symlinks in Windows Explorer and
Cygwin and thus making them *very* useful finally.

Frank-Michael

Corinna Vinschen wrote:
> On Aug  3 11:57, Brian Dessent wrote:
> 
>>Richard Campbell wrote:
>>
>>
>>>>To some degree, Junction Points are more like directory HARD links,
>>>>rather than symlinks.
>>>
>>>What degree is this?
>>>
>>>Everything I can see seems to say junction points function as symlinks
>>>for directories, with retargeting, dangling, and fixing options.
>>>
>>>I admit the documentation I have been looking at is sketchy - do you
>>>have some better info?
>>
>>You can't use a junction point to make a relative link, as you can with
>>symbolic links.  That makes them significantly less useful.
> 
> 
> That makes them next to useless from a POSIX point of view.  Actually,
> even though junction points allow to create links to directories on the
> same file system (but not to files *shaking head*), the important
> functionality is to allow to mount file systems into the hirarchy of
> another file system.  To me, junction points are more like mount points,
> not symlinks.  Since mount points are transparent and don't act like
> symlinks to cp/mv/rm and friends, I won't opt for treating junctions as
> symlinks in the Cygwin DLL.
> 
> At least not in the general case.  In theory, we could implement it like
> this:  If the target is a fs, treat the junction like a mount point (aka,
> transparently as a normal directory), otherwise, if the target is a
> directory, treat the junction as a symlink.
> 
> However, this is complicated, time consuming and error prone.  I can easily
> imagine that this behaviour results in a strange, unexpected behaviour for
> some people.
> 
> As a side note, I must admit that I was very excited when I heard about
> reparse points for the first time when Win2K was in Beta stage.  Back then,
> it sounded like the kitchen sink for getting rid of drive letters and to
> allow mounts and symlinks being implemented transparently throughout Cygwin
> and Win32 native apps.  Well, reality catched up pretty quickly...
> 
> 
> Corinna
> 


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