islower
__only_inline int islower(int _c)
#undef islower
islower(int c)
#define islower(c) ((c) >= 'a' && (c) <= 'z')
#define islower(c) ((c) >= 'a' && (c) <= 'z')
#define islower(c) ((c) >= 'a' && (c) <= 'z')