Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!joyce!sri-unix!quintus!pds
From: pds@quintus.uucp (Peter Schachte)
Newsgroups: comp.sys.amiga
Subject: Re: PATH: and (pseudo)announcement of RDF:
Message-ID: <586@quintus.UUCP>
Date: 27 Oct 88 21:21:08 GMT
References: <8810261744.AA28807@cory.Berkeley.EDU>
Sender: news@quintus.UUCP
Reply-To: pds@quintus.UUCP (Peter Schachte)
Organization: Quintus Computer Systems, Inc.
Lines: 43

In article <8810261744.AA28807@cory.Berkeley.EDU> dillon@CORY.BERKELEY.EDU (Matt Dillon) writes:
>	I agree, softlinks are a must!

Absolutely.

>	For softlinks, it seems pretty obvious that the way to implement
>them is to simply add a protection bit.

I'm not so sure.

Symbolic links could be implemented very simply as a generalization of
a device.  If an individual file could somehow specify that a
particular device driver be used to read it, instead of the one we'd
expect, then symbolic links would be easy.  But so would lots of other,
much more interesting things.

We could write a zoo.device, which zoo files would declare as their
device, and then we could do dir or list of them from the shell just as
if they were directories.  We could copy files into and out of them.
All this controlled by the device driver.

Another really neat use for this would be for keeping compressed files.
An individual file could specify its driver as compress.device, and when
the file is read, it would be uncompressed.  So it would be possible to
just say cc foo.c, where foo.c is such a compressed file, and as cc
reads foo.c's bytes, it gets them uncompressed.

Another use for this would be for files to keep track of their edit
history, sort of like sccs, only better.  You could just type the file
and see the latest version.  And writing to the file would automatically
take the differences from the previous version and remember them.  But a
special program would know how to get back old versions.

I think this generality would be REALLY useful.  It may sound esoteric,
but I expect you'd quickly find versions of compress.device showing up,
and wouldn't it be nice to transparently keep 1.5 Meg on a single
floppy that you don't update too often?  Or to transparently keep
histories of source code development with sccs.device?  This would blow
away what unix can do.

-Peter Schachte				"Clean water?  I'm for clean water."
pds@quintus.uucp				-George Bush
..!sun!quintus!pds