_L 22 include/linux/ctype.h #define isalnum(c) ((__ismask(c)&(_U|_L|_D)) != 0) _L 23 include/linux/ctype.h #define isalpha(c) ((__ismask(c)&(_U|_L)) != 0) _L 26 include/linux/ctype.h #define isgraph(c) ((__ismask(c)&(_P|_U|_L|_D)) != 0) _L 27 include/linux/ctype.h #define islower(c) ((__ismask(c)&(_L)) != 0) _L 28 include/linux/ctype.h #define isprint(c) ((__ismask(c)&(_P|_U|_L|_D|_SP)) != 0)