Signature:

      SUBROUTINE h5oget_info_by_idx_f(loc_id, group_name, index_field, order, n, &
           object_info, hdferr, lapl_id)

        USE, INTRINSIC :: ISO_C_BINDING
        IMPLICIT NONE
        INTEGER(HID_T)  , INTENT(IN)            :: loc_id
        CHARACTER(LEN=*), INTENT(IN)            :: group_name
        INTEGER         , INTENT(IN)            :: index_field
        INTEGER         , INTENT(IN)            :: order
        INTEGER(HSIZE_T), INTENT(IN)            :: n
        TYPE(h5o_info_t), INTENT(OUT), TARGET   :: object_info
        INTEGER         , INTENT(OUT)           :: hdferr
        INTEGER(HID_T)  , INTENT(IN) , OPTIONAL :: lapl_id

Inputs:

      loc_id      - File or group identifier specifying location of group
                    in which object is located.
      group_name  - Name of group in which object is located.
      index_field - Index or field that determines the order.
      order       - Order within field or index.
      n           - Object for which information is to be returned

Outputs:

      object_info - Buffer in which to return object information.
      hdferr      - Returns 0 if successful and -1 if fails.

Optional parameters:

      lapl_id     - Link access property list. (Not currently used.)