Infoworld: WebDAV Comes of Age

Chris Olds colds@dydax.com
Tue, 23 Oct 2001 14:00:13 -0400 (EDT)


On Tue, 23 Oct 2001, Mike Dierken wrote:
>
> > -----Original Message-----
> > From: J=F6sh [mailto:josh@bluescreen.org]
[...]
> > WinXP has included DAV support in "The Redirector" which is
> > the low level kernel/system interface that goes below the calls=20
> > like fopen().  However, it does not allow you to call fopen OR
> > a standard (old) file dialog with a URI.
> This sounds very cool, even with the minor limitation of the 'drive lette=
r'
> style hook. I didn't want to tackle that kind of code way back then. It s=
ure
> makes Windows more capable on a heterogenous network.

The redirector is the old way to do this.  Back in MS-DOS 3, they (MS)
needed a way to support all of the newfalgled networks out there without
opening up the entire OS.  The result was the Redirector, which allows
drivers to hook filename resolution and add drive letters.  This mechanism
was also how CD-ROM drives were supported when they came out (AFAIK, they
still are).  This is a very lightweight, and surprisingly functional way
to support additions to the filesystem namespaces, but in Windows the
redirector seems to have fallen out of favor as an extension mechanism.

At 3Com (in '86, when they still did their own client software) I
implemented the ability to use domain names in machine names with these
hooks.  'dir \\server.3com.com\share\*.*' worked just the way you might
expect (well, just the way I expected, anyway).  What's CIFS again?

It's really too bad - like Filesystem Reparse Points (which could also be
used to support WebDAV), the redirector is only used by programmers inside
MS because of the inadequate (or nonexistent) documentation and supporting
examples.  It's not hard, it's just *really* obscure.

=09/cco

p.s.  I saw DataChannel's 'Save to the web', and it was *very* cool.