isalnum
#define isalnum(c) __sbistype((c), _CTYPE_A|_CTYPE_D|_CTYPE_N)
static __inline int isalnum(int c)
isalnum(int c)
isalnum(int c)
#define isalnum(ch) (isalpha(ch) || isdigit(ch))
#undef isalnum
#define isalnum(c) ((__ctype + 1)[c] & (_U | _L | _N))
#define isalnum(c) (c > ' ' && (index("<@=>!:|\177", c) == NULL))
#define isalnum(c) (((c) >= '0' && (c) <= '9') || \
isalnum(char c)