isupper
#undef isupper
#define isupper(c) _bcs_isupper(c)
#undef isupper
#define isupper(c) _bcs_isupper(c)
isupper(int ch)
#define isupper(x) ('A' <= (x) && (x) <= 'Z')
#define isupper(c) ((int)((_ctype_tab_ + 1)[(c)] & _CTYPE_U))