Wheeler: Fixing Unix/Linux/POSIX Filenames [LWN.net]

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 26, 2009 2:25 UTC (Thu) by njs (subscriber, #40338)
In reply to: Wheeler: Fixing Unix/Linux/POSIX Filenames by nix
Parent article: Wheeler: Fixing Unix/Linux/POSIX Filenames

Too true. OS X solves this by defining a bespoke case normalization rule, the "HFS-Plus case-insensitive string comparison algorithm". They have their own big table and everything, you can download it at the first URL I gave. Awesome, huh?

I'd be happy if we could just make a rule that filenames are valid UTF-8. Unicode normalization (composing characters and all that) is probably a good idea, but reasonable people could disagree. I'm just as happy without case normalization (though the arguments for it aren't entirely without merit, even if it can't be done perfectly). And *any* of these would be better than what we have now...

(The "so what did you call this file?" API is also useful if your system ever deals with case-insensitive or unicode-normalizing filesystems. Which Linux does, whether it becomes common for the root filesystem or not.)

to post comments

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 26, 2009 13:42 UTC (Thu) by clugstj (subscriber, #4020) [Link] (6 responses)

"And *any* of these would be better than what we have now"

Why? How is the current condition so bad that we should run headlong into any of these "solutions" without knowing what the eventual outcome will be?

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 26, 2009 17:46 UTC (Thu) by quotemstr (subscriber, #45331) [Link]

We're talking about the possible outcomes. You're telling us we shouldn't discuss the possible problems and solutions because we don't know the problems yet? That's bunk.

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 26, 2009 18:59 UTC (Thu) by njs (subscriber, #40338) [Link] (4 responses)

...I started a thread by pointing to technical documentation on how this has worked for the last 8 years in the world's most widely-deployed Unix, and your response is that this is crazy to even consider because we have no way to know what will happen? C'mon... engage the actual arguments. I don't think it's obvious what the technically best solution is, but just because you haven't thought about the relevant details doesn't mean they aren't knowable.

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 29, 2009 21:27 UTC (Sun) by clugstj (subscriber, #4020) [Link] (1 responses)

I'm sorry, but when you said, that any of these propositions is better than the current situation, I HAD to disagree. In what way is the current situation so bad that any proposal is better that the current situation?

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 30, 2009 0:07 UTC (Mon) by njs (subscriber, #40338) [Link]

You cannot, in general, convert a filename to text. That's the fundamental problem that any of the proposals would solve.

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 29, 2009 21:30 UTC (Sun) by clugstj (subscriber, #4020) [Link] (1 responses)

OS X is trivial to handle. It only has to continue to work in a compatible way with the previous Mac OS - which wasn't UNIX. So using it as an example of how to "fix" these problems is not a good idea if you care about supporting 40+ years of UNIX programs - which is why this is difficult to change.

Wheeler: Fixing Unix/Linux/POSIX Filenames

Posted Mar 29, 2009 22:07 UTC (Sun) by foom (subscriber, #14868) [Link]

Eh...but OSX *does* run 40+ years of UNIX programs. It's pretty clear that the change to require
UTF-8 (and even the change to be case insensitive!) didn't bother most programs.