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From: ekrell@hector..UUCP (Eduardo Krell)
Newsgroups: comp.unix.wizards
Subject: Re: Symbolic Links
Message-ID: <2789@ulysses.homer.nj.att.com>
Date: Tue, 11-Aug-87 22:08:59 EDT
Article-I.D.: ulysses.2789
Posted: Tue Aug 11 22:08:59 1987
Date-Received: Thu, 13-Aug-87 07:08:31 EDT
References: <8731@brl-adm.ARPA>
Sender: daemon@ulysses.homer.nj.att.com
Reply-To: ekrell@hector (Eduardo Krell)
Organization: AT&T Bell Labs, Murray Hill
Lines: 48

I thought we went thru this a while ago ...

In article <8731@brl-adm.ARPA> rbj@icst-cmr.arpa writes:

(about RFS)

>My lack of specific knowledge of an obscure remote file system does not
>invalidate my general argument. I was asking him to justify his statement.

If you lack specific knowledge, then what authority do you have to call RFS
"an obscure remote file system"?. Or is this just System V or AT&T bashing?

>   BTW, NFS is hardly a model for "correct" semantics for UNIX file systems!
>
>Great, you just insulted Sun.

What's your point?. If you are going to have a distributed file system,
shouldn't you expect the same semantics independently of where the files
are? (aka "Location Transparency").

>1) The idea of following `cd /a/b' with `cd ..' and ending up in `/a'
>   is an attractive one, no doubt. There are many ways of doing this.
>   One is to do it in the shell, possibly with a switch enabling it.
>   In fact, csh's inability to handle its `cwd' variable across
>   symbolic links can be used to advantage: alias cdup 'cd $cwd:h'.

Doing it in the shell fixes the "cd /a/b; cd .." problem. But shouldn't
"cat ../foo" be the same as "cd ..; cat foo" ?. Now, how are you going
to do THAT in the shell?.

>3) However, there are real problems with attempting to reverse a
>   symlink *in the kernel*. Foremost is that different include files
>   would be referenced *depending on what path someone took to get
>   to the source directory*! This is unacceptable in my mind. It is
>   worse to reference the wrong file than to reference no file at all.

This has already been discussed. The solution is to make all the
subdirectories symbolic links as well.

>5) Symlinks are not only a means of linking across file systems, but
>   have other uses as well, namely an easy way of making links to
>   a directory and links to files which are renamed when edited.

But how does this relate to the original problem?
    
    Eduardo Krell                   AT&T Bell Laboratories, Murray Hill

    {ihnp4,seismo,ucbvax}!ulysses!ekrell