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From: rgrimes@acacia (Rodney W. Grimes)
Newsgroups: comp.os.386bsd.development
Subject: Re: A challenge to all true kernel hackers - conditional symlinks.
Message-ID: <1oelo8$dsc@walt.ee.pdx.edu>
Date: 20 Mar 93 08:48:08 GMT
Article-I.D.: walt.1oelo8$dsc
References: <1993Mar17.205308.5672@fcom.cc.utah.edu>
Organization: Portland State University
Lines: 41
NNTP-Posting-Host: acacia.cs.pdx.edu
terry@cs.weber.edu (A Wizard of Earth C) writes:
: In article <C40vy4.2D0@agora.rain.com> rgrimes@agora.rain.com (Rodney Grimes) writes:
: >terry@cs.weber.edu (A Wizard of Earth C) writes:
: >>The other fact, that the name space is only polluted for names beginning
: >>with "$(" means that collisoin is unlikely anyway, so the pollution is
: >>not disenfranchising "$", "(", and ")" as filename characters, but is
: >>instead diasallowing "$(" file names only.
: >
: >Not quite the whole story, if I remeber correctly from my apollo days,
: >if a variant link portion ie NAME in $(NAME) does not corresponde
: >to a valid environment variable it is left untranslated. So in
: >fact you can have a link foo -> $(BAR) that well get to file $(BAR)
: >as long as no environment variabled named BAR is defined.
:
: My take on this would be to translate it to nothing. This is what both
: the shell and make do with undefined environment variables that are
: used in an expansion.
Well that would seem logical, but then it would make it imposible to link
to files that had names of the form $(xxx), with the method of leaving it
untraslated you could have a link that resolved to $(FOO). Also I am not
sure what the implications of "$(HOME)/bin" get translatted to "{null}/bin"
might be. It surely would not be the desired results.
:
: The idea is not necessarily to mimic the Apollo (if mimicry were called
: for, I'd pick the NeXT), but to provide something that promotes ease of
: use in a distributed environment. Host, OS, and language dependencies
: coded into symbolic links are one tack to achieve this goal... perhaps
: not optimal, but something fun to play with.
Okay, but the original post that started this was from Jordan Hubbard and
he was specifically asking to mimic the apollo (not to nit pick, but it
is/was apollo, not Apollo) variant symbolic link.
:
: Has anyone heard from Martin Renters about the hard drive less boot
: disk he was working on lately?
I take it you mean a whole system running from floppy via NFS? If so
I have not heard of Martin Renters work, but I did some of my own, it's
not too hard, and variant symlinks would make it real easy.