преобразование входного формата (input format conversion)
Ошибки (Error)
EAGAIN The file descriptor underlying stream is marked
nonblocking, and the read operation would block.
EBADF The file descriptor underlying stream is invalid, or not
open for reading.
EILSEQ Input byte sequence does not form a valid character.
EINTR The read operation was interrupted by a signal; see
signal(7).
EINVAL Not enough arguments; or format is NULL.
ENOMEM Out of memory.
ERANGE The result of an integer conversion would exceed the size
that can be stored in the corresponding integer type.
