Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!apple!motcsd!xdos!doug
From: doug@xdos.UUCP (Doug Merritt)
Newsgroups: comp.sys.amiga.tech
Subject: Re: yet another 1.4 request
Message-ID: <402@xdos.UUCP>
Date: 1 Jul 89 02:30:50 GMT
References: <8906300342.AA12274@postgres.Berkeley.EDU> <398@xdos.UUCP> <7190@cbmvax.UUCP>
Reply-To: doug@xdos.UUCP (Doug Merritt)
Organization: Hunter Systems, Mountain View CA (Silicon Valley)
Lines: 50

In article <7190@cbmvax.UUCP> jesup@cbmvax.UUCP (Randell Jesup) writes:
>	To totally delete a hardlinked file, you must delete all the links/
>files.  To totally delete a soft-linked file, you must delete all the softlinks
>and the original file(link).

I missed this difference in semantics between (potential) AmigaDOS
soft links and Unix soft links (symbolic links). On Unix, the file goes
away as soon as you delete the "real" file, regardless of any remaining
softlinks to it. Deleting soft links never does anything to the original file.

>> [ ...I dismissed implementation "details"...]

>	Not when they mean an extra month or two of work for us, plus a slew
>of new bugs to weed out (FFS/OFS is getting rather crufty already, in trying
>to support things it wasn't designed to, especially since the same handler
>must deal with OFS disks, and write OFS disks that can be read by 1.3
>machines - no disk format changes).

I certainly sympathize. I just think it's appropriate to settle the
question of whether something is desirable under ideal circumstances first,
and *then* look at when. And the answer might be "don't hold your breath",
but at least it'd be known that the issue *was* desirable. Or not.
So far there doesn't seem to be much agreement.

>>I hate to do "cd directory; cd .." and discover that I haven't returned
>>to where I started. This never happens with hard links.

> [...] Plus, I think the shell should remember how you got where you are, 
>so cd'ing up one level will make it subtract 1 level from the previous string
>for current directory, then CD there.  (cd /foo/bar/zed, where zed is
>softlinked to /bar/foo/zed.  The shell would remember /foo/bar/zed as your
>current dir.  Then you cd .., and it removes zed from /foo/bar/zed, leaving
>/foo/bar, and cd's to there.)

Yeah, that's probably the best possible way to fix it. The fact that
such difficulties arise at all clearly comes about from the fact that
a purely hierarchical file system isn't quite powerful enough, but
current state of the art doesn't have the ideal solution to how to
handle a file system which is a graph. I think that this points in
the right direction, though, and the problem will be explored in more
detail as people get more familiarity with the issue of navigating
complexly structured hypermedia documents.

>	Also, how often do you cd to a hard-link on unix? :-)

Ouch. Got me there. I was inconsistent.
	Doug
-- 
Doug Merritt		{pyramid,apple}!xdos!doug
Member, Crusaders for a Better Tomorrow		Professional Wildeyed Visionary