Signature:

      SUBROUTINE h5pget_virtual_printf_gap_f(dapl_id, gap_size, hdferr)
        INTEGER(HID_T)  , INTENT(IN)  :: dapl_id
        INTEGER(HSIZE_T), INTENT(OUT) :: gap_size
        INTEGER         , INTENT(OUT) :: hdferr

Inputs:

      dapl_id    - Dataset access property list identifier for the virtual dataset

Outputs:

      gap_size - Maximum number of the files and/or datasets allowed to
                 be missing for determining the extent of an unlimited virtual
                 dataset with printf-style mappings.
      hdferr   - Returns 0 if successful and -1 if fails