Signature:

      SUBROUTINE h5pset_virtual_printf_gap_f(dapl_id, gap_size, hdferr)
        INTEGER(HID_T)  , INTENT(IN)  :: dapl_id
        INTEGER(HSIZE_T), INTENT(IN)  :: gap_size
        INTEGER         , INTENT(OUT) :: hdferr

Inputs:

      dapl_id  - Dataset access property list identifier for the virtual dataset.
      gap_size - Maximum number of files and/or datasets allowed to be missing
                 for determining the extent of an unlimited virtual dataset
                 with printf-style mappings.

Outputs:

      hdferr   - Returns 0 if successful and -1 if fails.