Ошибки открытия файла C++

http://www.rsdn.ru/forum/cpp/350673.flat

ANSI C supports a global variable (oh no, a global variable!) named errno which can be accessed by including errno.h When errors occur the variable is set to a standard error code which should be equivalent on all operating systems.

#define EZERO 0 /* Error 0 */
#define EINVFNC 1 /* Invalid function number */
#define ENOFILE 2 /* File not found */
#define ENOPATH 3 /* Path not found */
#define ECONTR 7 /* Memory blocks destroyed */
#define EINVMEM 9 /* Invalid memory block address */
#define EINVENV 10 /* Invalid environment */
#define EINVFMT 11 /* Invalid format */
#define EINVACC 12 /* Invalid access code */
#define EINVDAT 13 /* Invalid data */
#define EINVDRV 15 /* Invalid drive specified */
#define ECURDIR 16 /* Attempt to remove CurDir */
#define ENOTSAM 17 /* Not same device */
#define ENMFILE 18 /* No more files */

#define ENOENT 2 /* No such file or directory*/
#define EMFILE 4 /* Too many open files */
#define EACCES 5 /* Permission denied */
#define EBADF 6 /* Bad file number */
#define ENOMEM 8 /* Not enough core */
#define EFAULT 14 /* Unknown error */
#define ENODEV 15 /* No such device */
#define EINVAL 19 /* Invalid argument */
#define E2BIG 20 /* Arg list too long */
#define ENOEXEC 21 /* Exec format error */
#define EXDEV 22 /* Cross-device link */
#define ENFILE 23 /* UNIX - not MSDOS */
#define ECHILD 24 /* Unix/DOS */
#define ENOTTY 25 /* UNIX - not MSDOS */
#define ETXTBSY 26 /* UNIX - not MSDOS */
#define EFBIG 27 /* UNIX - not MSDOS */
#define ENOSPC 28 /* UNIX - not MSDOS */
#define ESPIPE 29 /* UNIX - not MSDOS */
#define EROFS 30 /* UNIX - not MSDOS */
#define EMLINK 31 /* UNIX - not MSDOS */
#define EPIPE 32 /* UNIX - not MSDOS */
#define EDOM 33 /* Math argument */
#define ERANGE 34 /* Result too large */
#define EEXIST 35 /* File already exists */
#define EDEADLOCK 36 /* Locking violation */
#define EPERM 37 /* UNIX - not MSDOS */
#define ESRCH 38 /* UNIX - not MSDOS */
#define EINTR 39 /* UNIX - not MSDOS */
#define EIO 40 /* UNIX - not MSDOS */
#define ENXIO 41 /* UNIX - not MSDOS */
#define EAGAIN 42 /* UNIX - not MSDOS */
#define ENOTBLK 43 /* UNIX - not MSDOS */
#define EBUSY 44 /* UNIX - not MSDOS */
#define ENOTDIR 45 /* UNIX - not MSDOS */
#define EISDIR 46 /* UNIX - not MSDOS */
#define EUCLEAN 47 /* UNIX - not MSDOS */

strerrno(errno)