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From: std-u...@ut-sally.UUCP (Moderator, John Quarterman)
Newsgroups: mod.std.unix
Subject: the scope of POSIX
Message-ID: <5966@ut-sally.UUCP>
Date: Thu, 9-Oct-86 12:33:13 EDT
Article-I.D.: ut-sally.5966
Posted: Thu Oct  9 12:33:13 1986
Date-Received: Fri, 10-Oct-86 00:50:34 EDT
Organization: IEEE P1003 Portable Operating System for Computer Environments Committee
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Approved: j...@sally.utexas.edu

From: cbosgd!cbosgd.ATT.COM!m...@seismo.css.gov (Mark Horton)
Date: Thu, 9 Oct 86 01:46:35 edt

The spirited debate about case sensitive file names raises
an important issue: what is the scope of POSIX?  I think the
answer to the case issue may depend on the answer to the
scope issue.  It's pretty clear that whether names are case
sensitive is a religious issue, with many people on each side.
While I hope somebody does a human factors study, I won't get
into the technical merits of the different sides here.

I used to think that P1003 was just to be a standard that all
the UNIX systems would conform to, e.g. a way to smash System
V and 4.2BSD and Xenix into enough similarity so that it would
be possible to write a program that will run on all of them.
If this is the real intent of POSIX, that it's really to be the
standard for UNIX, and the name is just a trademark game, then
it's pretty clear we want to keep filenames as they currently
are: case sensitive.

But I'm not sure POSIX has such a narrow scope.  I hear mention
of hosted implementations, but no cries of "foul" about the
case-sensitive ruling from the vendors of those hosted implementations,
so either they don't consider it a problem, or I'm missing something.

I personally think POSIX could easily have a MUCH wider scope.
Let's look into the crystal ball.  In a couple of years, IEEE
or FIPS or ANSI or ISO or somebody publishes a final "Standard
for Portable Operating System Interfaces."  Now, say I'm a vendor
of some other operating system (say MS DOS, or VMS, or OS9, or QNX,
or AOS, or VM/CMS, or pick your favorite proprietary operating system.)
I see this standard, and think "If we enhanced our OS to support all
this POSIX stuff, we'd be able to market our OS as POSIX compatible,
and there's be a big software base we'd automatically support, and
we'd be eligible for all those government contracts."  I'd sure think
seriously about making the necessary enhancements to my standard system
(not an emulation built on top) to make it comply.

Now, for the most part, adding UNIX/POSIX functionality would amount
to adding some enhancements to the system.  (There will probably be
some major surgery in areas like the filesystem, but we're still talking
about an enhanced result.)  However, if I were such a vendor, I'd be
pretty reluctant to take my case insensitive filesystem and make it
case sensitive.  (But I'm not such a vendor; it would be interesting
to hear what the real vendors have to say.)  After all, maybe nobody
uses UNIX with their caps lock key on, or on an upper case terminal,
but MY system has lots of users like that, and I don't want to break
the ability for the caps lock users to communicate with the lower case
users.

I think it would be appropriate to ask what the scope of POSIX should
be.  Maybe some vendors should be queried about whether they might be
interested in someday conforming their systems to POSIX, and how they
feel about the case properties of their system.  They're the ones who
are really affected by all this.  Me, I'm used to doing everything in
lower case, as are most of you reading this.

	Mark

Volume-Number: Volume 7, Number 41