Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!rutgers!seismo!mimsy!chris
From: chris@mimsy.UUCP
Newsgroups: comp.unix.wizards
Subject: Re: Symbolic Links
Message-ID: <8195@mimsy.UUCP>
Date: Thu, 27-Aug-87 02:01:01 EDT
Article-I.D.: mimsy.8195
Posted: Thu Aug 27 02:01:01 1987
Date-Received: Sat, 29-Aug-87 07:43:35 EDT
References: <8731@brl-adm.ARPA> <2789@ulysses.homer.nj.att.com> <1781@munnari.oz> <2877@ulysses.homer.nj.att.com>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 56

In article <2877@ulysses.homer.nj.att.com> ekrell@hector.UUCP
(Eduardo Krell) writes:
>... I just went thru all the files in /usr/include/sys under System
>V Release 3 and there is no #include "../<anything>".
>There are some in BSD 4.3 in the form #include "../machine/foo.h" which
>should really be #include <machine/foo.h>.

No, they should not be that way; and: they are already that way.

(What?)

Look more closely:  These files read

	#ifdef KERNEL
	#include "../machine/pte.h"
	#else
	#include <machine/pte.h>
	#endif

which is as it should be---one should be able to build experimental
kernels without reference to /usr/include.

>In our system, /usr/include/sys is a symbolic link to /sys/h. If a cd to
>/usr/include/sys, I can do "ls" and see all the header files. If I do "ls ..",
>I don't get /usr/include.
>If I do "cd /usr/include/sys" and then "ls ..", if I don't get the contents
>of /usr/include, something is broken, period.

Say not `period', but rather, according to the way you and a large
group of others feel things should be done.

>... It's 100% deterministic, you tell me how you got there and I'll
>tell you what ".." means.

It is deterministic; but it is context sensitive.  This is what I
do not like, and I think this is what Robert Elz does not like.

>I know links to directories destroy the tree structure. Now, the questions
>is: provided we don't have tree structure anymore, what's the next best thing?

And this is the center of the argument.  The two sides seem to be

	the next best thing is ..-as-a-logical-operator (`up'):
	make it *look* like a tree

and

	the next best thing is directed acyclic graph behaviour

and I think everyone knows on which side we stand. . . .

(Incidentally, I have a C shell alias `up': `cd /$cwd:h'; when I
want to go up, I type `up'.)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
Domain:	chris@mimsy.umd.edu	Path:	seismo!mimsy!chris