46 lines
919 B
C
46 lines
919 B
C
|
|
/*
|
|
FUNCTION
|
|
<<isxdigit>>---hexadecimal digit predicate
|
|
|
|
INDEX
|
|
isxdigit
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <ctype.h>
|
|
int isxdigit(int <[c]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
#include <ctype.h>
|
|
int isxdigit(int <[c]>);
|
|
|
|
DESCRIPTION
|
|
<<isxdigit>> is a macro which classifies ASCII integer values by table
|
|
lookup. It is a predicate returning non-zero for hexadecimal digits,
|
|
and <<0>> for other characters. It is defined only if <[c]> is
|
|
representable as an unsigned char or if <[c]> is EOF.
|
|
|
|
You can use a compiled subroutine instead of the macro definition by
|
|
undefining the macro using `<<#undef isxdigit>>'.
|
|
|
|
RETURNS
|
|
<<isxdigit>> returns non-zero if <[c]> is a hexadecimal digit
|
|
(<<0>>--<<9>>, <<a>>--<<f>>, or <<A>>--<<F>>).
|
|
|
|
PORTABILITY
|
|
<<isxdigit>> is ANSI C.
|
|
|
|
No supporting OS subroutines are required.
|
|
*/
|
|
#include <_ansi.h>
|
|
#include <ctype.h>
|
|
|
|
|
|
#undef isxdigit
|
|
int
|
|
_DEFUN(isxdigit,(c),int c)
|
|
{
|
|
return(__ctype_ptr__[c+1] & ((_X)|(_N)));
|
|
}
|
|
|