Case sensitive file names

Moderator, John Quarterman std-unix at ut-sally.UUCP
Wed Nov 5 03:36:22 AEST 1986


From: chris at mimsy.umd.edu (Chris Torek)
Date: Tue, 4 Nov 86 07:33:44 EST

We seem to have three proposals:

CS: Case sensitive file systems.  This is what all major Unix variants
    (V6, V7, SysIII, SysV, 2BSD, and 4BSD) now support.

CC: Case coercive file systems (file names forced to all upper or all
    lower case).

CR: Case retaining but otherwise insensitive file systems (new names
    are created according to the given case; matches are not case
    sensitive).

I sincerely hope that no one is seriously suggesting POSIX adopt
CC: no one seems to like such systems much.  That leaves CS and
CR.  The case for CR appears to be that those who have used both
CS and CR prefer CR.  This may be true; I have seen no studies,
but the anecdotes do seem to favour it.  I have used such a system,
and did not think it so wonderful, but for the sake of argument,
let us assume that CR really is objectively better than CS---so
much so that 5BSD and System V Release N+1 will have CR style file
systems.  Fine.

But as I understand it, POSIX is intended to be an interface
specification for something that resembles `Unix' (whatever `Unix'
may be).  If that is indeed the case, the only sensible choice is
CS, for, as I noted above, this is what all major Unix variants
*do*.  *They all agree:* file names are case sensitive.  Should
we make standard something that no one uses?  I say no!  When
5BSD and Release N+1 come out, then we can create a new standard
to describe these wonderful new systems, but until then, let
us write something that describes what we have now.

I believe that the first standard for *anything* that already exists
should describe the existing implementations, at least wherever
they agree.  Afterward, feel free to invent new improved standards,
so as to foist progress upon vendors.  Indeed, it might not be a
bad idea to publish two standards virtually simultaneously: That
Which Is, and That Which Should Be.  But list first That Which Is.

[ There really are (or at least were) two discussions going on here:
one about what should be in POSIX, the other about what UNIX should do.
I haven't seen any recent arguments that POSIX should do anything but
reflect what UNIX currently does, i.e., case sensitive file names
(really file names as uninterpreted byte streams).  -mod ]

-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at mimsy.umd.edu

Volume-Number: Volume 8, Number 34



More information about the Mod.std.unix mailing list