int errno;
#define ENOENT	-1
#define E2BIG	-2
#define EBADF	-3
#define ENOMEM	-4
#define EEXIST	-5
#define EINVAL	-6
#define ENFILE	-7
#define EMFILE	-8
#define ENOTTY	-9
#define EACCES	-10

#define ERANGE	-20
#define EDOM	-21