Signature:

      SUBROUTINE h5pget_file_image_f(fapl_id, buf_ptr, buf_len_ptr, hdferr)
        USE iso_c_binding
        IMPLICIT NONE
        INTEGER(HID_T) , INTENT(IN)                :: fapl_id
        TYPE(C_PTR)    , INTENT(OUT), DIMENSION(*) :: buf_ptr
        INTEGER(SIZE_T), INTENT(OUT)               :: buf_len_ptr
        INTEGER        , INTENT(OUT)               :: hdferr

Inputs:

      fapl_id     - File access property list identifier.

Outputs:

      buf_ptr     - Will hold either a C_NULL_PTR or a scalar of type
                    c_loc. If buf_ptr is not C_NULL_PTR, on successful
                    return, buf_ptr shall contain a C pointer to a copy
                    of the initial image provided in the last call to
                    H5Pset_file_image_f for the supplied fapl_id, or
                    buf_ptr shall contain a C_NULL_PTR if there is no
                    initial image set.

      buf_len_ptr - Contains the value of the buffer parameter for
                    the initial image in the supplied fapl_id. The value
                    will be 0 if no initial image is set.

      hdferr      - Returns 0 if successful and -1 if fails