Return_Values

   x                  The number of successfully matched and
                      assigned input items.
   EOF                Indicates that the end-of-file was encountered
                      or a read error occurred. If a read error
                      occurs, the function sets errno to one of the
                      following:

                      o  EILSEQ - Invalid character detected.

                      o  EVMSERR - Nontranslatable OpenVMS error.
                         vaxc$errno contains the OpenVMS error code.
                         This can indicate that conversion to a
                         numeric value failed due to overflow.

                      The function can also set errno to the
                      following as a result of errors returned from
                      the I/O subsystem:

                      o  EBADF - The file descriptor is not valid.

                      o  EIO - I/O error.

                      o  ENXIO - Device does not exist.

                      o  EPIPE - Broken pipe.

                      o  EVMSERR - Nontranslatable OpenVMS error.
                         vaxc$errno contains the OpenVMS error code.
                         This indicates that an I/O error occurred
                         for which there is no equivalent C error
                         code.