Re: Unicode, Korean, normalization form, Mac OS X and tab completion

[Daniel Shahaf <d.s@daniel.shahaf.name>]

Bart Schaefer wrote on Sat, May 31, 2014 at 14:29:26 -0700:
> On May 31,  8:16pm, Peter Stephenson wrote:
> }
> } I'm currently wondering if there is scope for normalising keyboard input
> } really early --- before we feed it back to the shell --- and turning it
> } back into the usual keyboard form right at the end
> 
> Per thread with Chet, I think normalizing the filesystem is the easier
> way to go.  Keyboard input is already as close to normalized as it needs
> to be, I think, and with only a couple of exceptions all the names we
> get from the filesystem come through zreaddir().

What about, say, people doing 'ls' and copy-pasting a filename from the
output into a command line?  Wouldn't that result in NFD keyboard
input?

FWIW, while OS X always returns NFD filenames, one could also imagine an
OS that is normalization-aware (forbids creating a file if its
normalized name is the same as the normalized name of an existing file)
but octet-sequence-preserving, and on such an OS both the readdir()
output and the user input would need to be normalized.

Also, other unixes allow you to have both the NFC-form and NFD-form in
the same directory, e.g., 'touch fooá fooá' works just fine on linux
ext4 (the first filename is composed, the second decomposed); in such
cases normalization magic should not be done.

Fun! :-)

Daniel