interface
  Subroutine PetscFortranPrintToFileUnit(unit, str, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    integer unit
    character(len=*), intent(in) :: str
    PetscErrorCode, intent(out):: ierr
  End Subroutine
  Subroutine PetscViewerASCIIOpenWithFileUnit(comm, unit, lab, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    MPI_Comm, intent(in) :: comm
    integer, intent(in) :: unit
    PetscViewer, intent(out) :: lab
    PetscErrorCode, intent(out):: ierr
  End Subroutine
  Subroutine PetscViewerASCIISetFileUnit(lab, unit, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer, intent(in) :: lab
    integer, intent(in) :: unit
    PetscErrorCode, intent(out):: ierr
  End Subroutine
end interface

Interface PetscViewerBinaryWrite
  Subroutine PetscViewerBinaryWriteInt(v, a, cnt, tmp, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer v
    PetscInt a(*)
    PetscInt cnt
    PetscBool tmp
    PetscErrorCode, intent(out):: ierr
  End Subroutine

  Subroutine PetscViewerBinaryWriteScalar(v, a, cnt, tmp, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer v
    PetscScalar a(*)
    PetscInt cnt
    PetscBool tmp
    PetscErrorCode, intent(out):: ierr
  End Subroutine

#if defined(PETSC_USE_COMPLEX)
  Subroutine PetscViewerBinaryWriteReal(v, a, cnt, tmp, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer v
    PetscReal a(*)
    PetscInt cnt
    PetscBool tmp
    PetscErrorCode, intent(out):: ierr
  End Subroutine
#endif
End Interface PetscViewerBinaryWrite

Interface PetscViewerBinaryRead
  Subroutine PetscViewerBinaryReadInt(v, a, cnt, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer v
    PetscInt a(*)
    PetscInt cnt
    PetscErrorCode, intent(out):: ierr
  End Subroutine

  Subroutine PetscViewerBinaryReadScalar(v, a, cnt, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer v
    PetscScalar a(*)
    PetscInt cnt
    PetscErrorCode, intent(out):: ierr
  End Subroutine

#if defined(PETSC_USE_COMPLEX)
  Subroutine PetscViewerBinaryReadReal(v, a, cnt, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer v
    PetscReal a(*)
    PetscInt cnt
    PetscErrorCode, intent(out):: ierr
  End Subroutine
#endif
End Interface PetscViewerBinaryRead

interface PetscViewerHDF5WriteAttribute
  subroutine PetscViewerHDF5WriteAttributeInt(viewer, parent, name, value, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer :: viewer
    character(len=*), intent(in) :: parent, name
    PetscInt, intent(in) :: value
    PetscErrorCode, intent(out):: ierr
  end subroutine PetscViewerHDF5WriteAttributeInt

  subroutine PetscViewerHDF5WriteAttributeScalar(viewer, parent, name, value, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer :: viewer
    character(len=*), intent(in) :: parent, name
    PetscScalar, intent(in) :: value
    PetscErrorCode, intent(out):: ierr
  end subroutine PetscViewerHDF5WriteAttributeScalar

#if defined(PETSC_USE_COMPLEX)
  subroutine PetscViewerHDF5WriteAttributeReal(viewer, parent, name, value, ierr)
    use, intrinsic :: ISO_C_binding
    import tPetscViewer
    PetscViewer :: viewer
    character(len=*), intent(in) :: parent, name
    PetscReal, intent(in) :: value
    PetscErrorCode, intent(out):: ierr
  end subroutine PetscViewerHDF5WriteAttributeReal
#endif

end interface PetscViewerHDF5WriteAttribute