%N hmode %F $MIR/src/subs/hio.c
%D Return access modes of a dataset.
%P pjt
%: low-level-i/o
%B
FORTRAN call sequence
        subroutine hmode(tno,mode)
        integer tno
        character mode*(*)

  Determine the access modes of a data-set

  Input:
    tno         The handle of the data set.
  Output:
    mode        This will be either "" (unknown access mode),
                                    "r" (read-only)
                                    "rw" (read-write).                  
