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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.unix.wizards
Subject: Re: Symbolic Links
Message-ID: <8137@mimsy.UUCP>
Date: Tue, 25-Aug-87 01:06:21 EDT
Article-I.D.: mimsy.8137
Posted: Tue Aug 25 01:06:21 1987
Date-Received: Wed, 26-Aug-87 01:51:48 EDT
References: <8731@brl-adm.ARPA> <2789@ulysses.homer.nj.att.com> <1781@munnari.oz> <2854@ulysses.homer.nj.att.com>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 33

>In article <1793@munnari.oz> kre@munnari.UUCP writes:
>>If we're there in /c/d (a path without symlinks, as obtained from /bin/pwd)
>>and you do a "cd ..", where should we go?  I say wherever ".." points,
>>usually "/c", in all cases.  Simple, and consistent.  It does require
>>some education about the properties of symlinks.

In article <2854@ulysses.homer.nj.att.com> ekrell@hector.UUCP
(Eduardo Krell) writes:
>This argument, that ".." is a physical link (rather than a logical one)
>falls appart at mount points, where the parent directory and where ".."
>points are different.  It also happens at remote file system mount
>points, for the same reason.

Mount points are (1) required to be on a leaf and (2) mount the root
of a tree.  (That (1) is enforced by hiding anything that is under
the mount point is irrelevant.)  This means that mount points leave
the file system tree-structured.

The *raison d'etre* for symbolic links is that sometimes a tree
structure is insufficient.  It should follow that they do not behave
like trees.

If you wish to treat all path names as strings before attempting to
apply them to the file system itself, and resolve `..' as `up one
level', we can discard the entire directory structure of Unix itself.
There is no need for `.' and `..' directory entries.  These become
magic strings.  There is no need for the file system to be implemented
as a directed graph (although it may still be convenient).

It may be convenient, but it does not feel like Unix.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
Domain:	chris@mimsy.umd.edu	Path:	seismo!mimsy!chris