/* FUNCTION <>---hexadecimal digit predicate INDEX isxdigit ANSI_SYNOPSIS #include int isxdigit(int <[c]>); TRAD_SYNOPSIS #include int isxdigit(int <[c]>); DESCRIPTION <> 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 when <>(<[c]>) is true or <[c]> is EOF. You can use a compiled subroutine instead of the macro definition by undefining the macro using `<<#undef isxdigit>>'. RETURNS <> returns non-zero if <[c]> is a hexadecimal digit (<<0>>--<<9>>, <>--<>, or <>--<>). PORTABILITY <> is ANSI C. No supporting OS subroutines are required. */ #include <_ansi.h> #include #undef isxdigit int _DEFUN(isxdigit,(c),int c) { return((_ctype_ + 1)[c] & ((_X)|(_N))); }