Case sensitive file names: what do other systems do

[std-unix at ut-sally.UUCP]

From: seismo!mcvax!guido (Guido van Rossum)
Date: Thu, 23 Oct 86 23:19:13 +0100

In article <6029 at ut-sally.UUCP>, Mark Horton writes:
>I think it would be interesting to hear what other, case-insensitive
>operating systems do about these issues.  What do MS DOS, or VM/CMS,
>or VMS, or whatever, do with their case insensitive file names in
>Europe, or Japan, or whereever?

Since you are asking:

I know quite well what two other case-insensitive systems do.  They take
extreme positions (while both being case-insensitive!).  To wit:

MS-DOS:

- Everything is in upper case (lower case is accepted by system calls
  but you get upper case back by directory searches etc.).
- Allows only alphanumerics and a very small set of punctuation
  characters; the rest are sort of ignored or considered as terminators!
- This means Germans etc. are in the same position as just after the
  invention of the telegraph.  (The Dutch don't particularly mind
  because they use few special characters and never know exactly where
  an umlaut should go anyway (we don't call it an umlaut, actually, but
  the Dutch word wouldn't make sense to most readers of this message).)

Apple Macintosh:

- The case given when a file was created is retained in the directory
  listing so it is possible to make a file name stand out by calling it
  "READ ME" (yes, with spaces!).
- All characters of the Mac's 8-bit character set are allowed, except
  the colon, which serves as a pathname delimiter ('/' in Unix).  This is
  USASCII extended with all sorts of odd characters used in all sorts of
  foreign languages (as long as they use the latin alphabet as a base).
  Even chracters that don't have a representation in the commonly used
  fonts are allowed; even the null character, (although this possibility
  necessarily disappears in the C interface).
  There is a mapping between the cases which can be used for various
  purposes; A and a correspond in this mapping, but accented characters
  are not the same as their other case counterparts (I believe --
  someone borrowed my copy of Inside Macintosh).  This mapping is used
  when files are opened, etc.  There is also a collating sequence for
  arbitrary strings which can be changed by different countries.
- Germans, French and Swedes should be perfectly happy with this, unless
  they happen to be case-sensitivity-freaks.  I don't know about the
  Japanese, but they could get away quite well if they use a different
  mapping to character glyphs (which is quite simple to do on the Mac).

(BTW, I think Apple has also designed decent solutions to other
internationalization issues -- their date and time notation, and probably
that for currency also, can be adapted to any of the European countries
in which they sell computers!)

Oh, just in case votes are taken: I am *for* case sensitivity.
John Bruner put it quite well.

	Guido van Rossum, CWI, Amsterdam <guido at mcvax.uucp>

Volume-Number: Volume 7, Number 90