Trying to design low level hard disk manipulation program
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From: Rob Warnock on 26 Sep 2006 05:09 Jan Vorbr?ggen <jvorbrueggen(a)not-mediasec.de> wrote: +--------------- | The A320 crash at Strasbourg occured, in the final account, because | in the display for the descent rate it made a difference whether it | showed "3" or "3.". +--------------- IIRC, one meant "300 ft/min" [a rather slow rate of descent for an A320] and the other meant "3 degrees" down from horizontal, which at 250 kts is ~1326 ft/min [rapid, but not excessive for an A320] or at 400 kts is ~2121 ft/min [quite rapid]. +--------------- | Nobody in the cockpit noticed this, and the crew likely | didn't even know what the presence or absence of the "." meant. +--------------- I'm sure that they had been taught at some point [in order to qualify to fly that plane] but may have either forgotten or, more likely, not noticed when it automatically switched from one mode to the other. If fact, ISTR that was the case -- the autopilot automatically switched the display format from one mode to another under certain circumstances *without* sounding any audible alerts. +--------------- | That's just bad design +--------------- Agreed. +--------------- | as is allowing the case of letters in a filename to distinguish files. +--------------- Disagree, emphatically. -Rob ----- Rob Warnock <rpw3(a)rpw3.org> 627 26th Avenue <URL:http://rpw3.org/> San Mateo, CA 94403 (650)572-2607
From: Nick Maclaren on 26 Sep 2006 05:13 In article <4ns1vjFbrltjU2(a)individual.net>, =?ISO-8859-1?Q?Jan_Vorbr=FCggen?= <jvorbrueggen(a)not-mediasec.de> writes: |> |> No, that's not what I meant. I asked whether there are languages that use the |> same letters, but for which the mapping between upper- and lower-case is in- |> compatible. Yes, many. In particular, different varieties of French (and, I believe, German) have different rules on what you should do when upper-casing 'accented' letters. Even English varies, though not the modern dumbed-down and Americanised forms (consider diaeresis and diphthongs). Regards, Nick Maclaren.
From: Benny Amorsen on 26 Sep 2006 05:17 >>>>> "DR" == Dennis Ritchie <dmr(a)bell-labs.com> writes: DR> Nonsense. Keeping the case the user specified was a choice. DR> Case-squashing would be a very few instructions. In the specific case of simplified English, it's certainly easy. Once you allow naïve, it gets more interesting, but if Unix on the PDP series stuck with ASCII, that wouldn't be a problem. Not that a lookup table for a simple 8-bit-encoding would be much trouble either. /Benny
From: Andrew Reilly on 26 Sep 2006 05:18 On Tue, 26 Sep 2006 09:25:38 +0200, Jan Vorbr?ggen wrote: >>>None of any worth IMO. But case smashing to provide a case blind name >>>space takes code, and would not fit into a PDP7/11 address space. >> Nonsense. Keeping the case the user specified was a choice. >> Case-squashing would be a very few instructions. > > I'm all for keeping the user's choice of case, but making it irrelevant > on compare. Would that still be "a very few instructions", in your opinion? Sure, and what's more, it happens outside the file system, if you want it. What real benefit does case insensitivity offer, though? The "average users" who's sensibility that this seems to be aimed to preserve don't type existing file names anyway: they click on them when presented with a list from a search or in a file browser view. File names are entered only on creation, and in that case, the case is preserved. For coders and systems people, the advantage of having a system that doesn't do magical or inexplicable things on one's behalf is a much greater benefit. IMHO, of course. Cheers, -- Andrew
From: Jan Vorbrüggen on 26 Sep 2006 05:25
> I have used systems that did just that. I suspect so...I consider it one of the (few) things Winwoes got right. > It is a negligible number of instructions, but is rather confusing - > consider putting a list of names into sort or uniq - should the default > be case sensitive or insensitive? The sort should be case-blind - which is, from my cursory testing just now, what Windows does. Jan |