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/*
FUNCTION
<<isdigit>>, <<isdigit_l>>---decimal digit predicate
INDEX
isdigit
INDEX
isdigit_l
SYNOPSIS
#include <ctype.h>
int isdigit(int <[c]>);
#include <ctype.h>
int isdigit_l(int <[c]>, locale_t <[locale]>);
DESCRIPTION
<<isdigit>> is a macro which classifies singlebyte charset values by table
lookup. It is a predicate returning non-zero for decimal digits, and 0 for
other characters. It is defined only if <[c]> is representable as an
unsigned char or if <[c]> is EOF.
<<isdigit_l>> is like <<isdigit>> but performs the check based on the
locale specified by the locale object locale. If <[locale]> is
LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
You can use a compiled subroutine instead of the macro definition by
undefining the macro using `<<#undef isdigit>>' or `<<#undef isdigit_l>>'.
RETURNS
<<isdigit>>, <<isdigit_l>> return non-zero if <[c]> is a decimal digit
(<<0>>--<<9>>).
PORTABILITY
<<isdigit>> is ANSI C.
<<isdigit_l>> is POSIX-1.2008.
No supporting OS subroutines are required.
*/
#include <_ansi.h>
#include <ctype.h>
#undef isdigit
int
isdigit (int c)
{
return(__CTYPE_PTR[c+1] & _N);
}
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