here are the basics of what you need to implement needshumanquote.
you will also need to add these prototypes to libc.h:

int isspacerune(Rune);
int isdigitrune(Rune);		// recognizes (super|sub)script/indic/tamil/thai/... digits
int digitrunevalue(Rune);		// converts a rune to it's numeric value.  -1 if not a digit.

my utf tables are a little bit different than the distribution.  i believe that
most of the differences are due to the fact that i generated my tables from unicode-4.1.

i'll be happy to submit a patch, if there's any interest.

- erik

> the purpose of the function is to determine if the string needs
> quoting for
> rc's benefit.

>I agree current quote is designed for rc benefit.
>But I want something that helps for human reading.
>
>needshumanquote(int r) or the improved version will be nice
>if it is available in ls command.