Re^2: Another pitfall. Signed chars and ctype.h.

[Heinz Weber]

john at frog.UUCP (John Woods) writes:

>In article <Chsv$q2 at cs.psu.edu>, flee at shire.cs.psu.edu (Felix Lee) writes:
>> If you have "char * s;" you cannot say something like "isdigit(*s)" if
>> you want to be 8-bit clean.  "isdigit" etc. take an (int) in the range
>> [-1, UCHAR_MAX].
>> You have to say "isdigit((unsigned char) *s)".

>You have ahold of the wrong end of the stick.

>You have to say

>	isascii(*s) && isdigit(*s)

>isdigit() and friends are all only defined on those values for which
>isascii() is true.  

You are right, this is what's defined in the X/OPEN Portability Guide.
But you don't meet the problem. I want German Umlauts to be no space
char's and printable an so on, e.g. the german "oe", that is 0xf6 in
the international char set. I'm not interested in isascii(0xf6) = not true!
So, the only chance you have is to take unsigned char to get the right
index into the ctype-vector.

Heinz

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