Re: Can not stat file with utf char U+F020

[Brian Inglis <Brian.Inglis@Shaw.ca>]

On 2023-04-14 13:00, Corinna Vinschen via Cygwin wrote:
> On Apr 14 19:53, Gionatan Danti via Cygwin wrote:
>> I have an issue with unreadable files with contain utf char U+F020 (which
>> appear as "middle dot with some space after") in their name.
>> stat on such a file results in "no such file or directory"
>>  From here [1] it seems that a patch was contemplated many years ago, but I
>> don't know its status now.
>> Any ideas or workaround?

> There's no (good) solution from inside Cygwin.
> Keep in mind that the Unicode area from U+E000 up to U+F8FF is called
> "Private Use Area".  So none of the chars are mapped into any
> singlebyte, doublebyte, or multibyte charset.  Typically we don't expect
> that filenames contain any of these chars, and we're only using a very
> small subset of them for our own, dubious purposes anyway:
> https://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-specialchars

>> [1] https://sourceware.org/legacy-ml/cygwin/2009-11/msg00043.html

> While this patch would have fixed your problem, a later followup patch
> broke your usage of U+F020 (space replacement) and, FWIW, of U+F02E
> (dot replacement) again:
> 	https://cygwin.com/cgit/newlib-cygwin/commit/?id=8802178fddfd
> This was done to accomodate filesystems implementing the idiotic
> approach to support only DOS filenames, i.e. not allowing leading or
> trailing spaces and not allowing trailing dots. These are Netapp and
> Novell Netware filesystems. See the last paragraph of
> https://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-specialchars
> Any chance you can just rename the files?

UCSUR Under-ConScript Unicode Registry and its predecessor ConScript Unicode 
Registry CSUR

	https://www.kreativekorp.com/ucsur/

	http://www.evertype.com/standards/csur/

unofficially register Unicode PUA glyphs for academic, artificial, constructed, 
historical, invented, and minority language scripts, some of which have made it 
into Unicode e.g.

	Script		CSUR		Unicode
	PHAISTOS DISC	U+E6D0-U+E6FF	U+101D0-U+101DF
	SHAVIAN		U+E700-U+E72F	U+10450-U+1047F
	DESERET		U+E830-U+E88F	U+10400-U+1044F

and maintain their own Unidata e.g.

	https://www.kreativekorp.com/ucsur/UNIDATA/Blocks.txt

and some Unicode fonts have -CSUR addition files (like -Italic etc.) that 
support BMP and SMP PUA glyphs.

For Cygwin purposes:

F000−F7FF	unassigned	Reserved for hacks and corporate use

so Cygwin's special Windows file name characters mappings are clear:

	F022	"
	F02A	*
	F03A	:
	F03C	<
	F03E	>
	F03F	?
	F07C	|

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer     but when there is no more to cut
                                 -- Antoine de Saint-Exupéry