!  $Id: io.f,v 1.4 2000/09/24 19:24:44 aake Exp $
************************************************************************
*
*  This part contains the I/O files that do not depend on the number
*  of variables to save (HD or MHD).
*
************************************************************************
      subroutine open_write_file (file, nio)
*
*  Controls where the outdata file is opened.  If the filename ends
*  on `.cm', the file is on the data vault, otherwise the data is on
*  the frontend (opened and closed each time).
*
      include 'cparam.inc'
      character *(mfile) file
      integer nio
*-----------------------------------------------------------------------

      end
************************************************************************
      subroutine close_write_file (file)
*
*  Close the output data file
*
      include 'cparam.inc'
      character *(mfile) file
*-----------------------------------------------------------------------
*
      end
************************************************************************
      subroutine start_data (case, file, nio)
*
*  Controls where the in data is found.
*  If the filename ends on `.cm', the file is on the data vault,
*  if the filename ends in '.start' a startup routine is called,
*  else the data is on the frontend.
*
*  Update history:
*
*   7-jun-92/axel: enable input of t from the dummy layer
*
      include 'cparam.inc'
      include 'cdata.inc'
      include 'cwork.inc'
      character *(mfile) case, file
*-----------------------------------------------------------------------
*
      init=0
      if (file(1:4) .eq. 'init') init=1
      call start (case, init)
*
      if (file(1:4) .ne. 'init') then
         call read_front (file, nio)
      endif
*
      end
************************************************************************
      subroutine write_data (file, nio)
*
*  Controls where the outdata is written.
*  When the filename ends on `.cm', the file is on the data vault,
*  else the data is on the frontend.
*
      include 'cparam.inc'
      include 'cdata.inc'
      include 'cwork.inc'
      character *(mfile) file
      integer dot
*-----------------------------------------------------------------------
*
      call write_front (file, nio)
*
*  File for common block
*
      dot = index(file,'.')
      open (12, file=file(1:dot)//'com',
     &         status='unknown', form='unformatted',
     &         access='direct', recl=lrec(50))
      write (*,*) 'common:', file(1:dot)//'com', nio-1
      include 'cwrite_com.inc'
      close (12)

      open (12, file=file(1:dot)//'dim',
     &         status='unknown', form='formatted')
      write (12,'(3i5)') mx,my,mz
      write (12,'(3(1pe12.5))') dx, dy, dz
      ixvert = 1
      write (12,'(f9.6,i3)') gamma, ixvert
      write (12,'(i3)') mvar
      close (12)
*
      end
************************************************************************
      subroutine read_cdata (file, nio)
*
*  Reads /cdata/ common block from direct access file
*
      include 'cparam.inc'
      include 'cdata.inc'
      character *(mfile) file
      integer dot
*-----------------------------------------------------------------------
*
*  File for common block
*
      dot = index(file,'.')
      open (12, file=file(1:dot)//'com',
     &         status='old', form='unformatted',
     &         access='direct', recl=lrec(50), err=99)
      write (*,*) 'reading common block record ',nio-1,' from ',file
      include 'cread_com.inc'
      close (12)
*
 99   continue
      end
************************************************************************
*
*  This part contains the I/O files for the HD and MHD cases.
*
************************************************************************
      subroutine read_front (file, nio)
*
*  Read data from the frontend.
*
      include 'cparam.inc'
      include 'cwork.inc'
      character *(mfile) file
*-----------------------------------------------------------------------
*
      open (10, file=file,
     &      status='old', form='unformatted',
     &      access='direct', recl=lrec(mw))

      read(10,rec=(nio - 1)*mvar + 1) r
      read(10,rec=(nio - 1)*mvar + 2) px
      read(10,rec=(nio - 1)*mvar + 3) py
      read(10,rec=(nio - 1)*mvar + 4) pz
      read(10,rec=(nio - 1)*mvar + 5) e
      if (mvar.gt.5) then
        read(10,rec=(nio - 1)*mvar + 6) bx
        read(10,rec=(nio - 1)*mvar + 7) by
        read(10,rec=(nio - 1)*mvar + 8) bz
      endif
*
      close (10)
*
      end
************************************************************************
      subroutine write_front (file, nio)
*
*  Write data to the frontend.
*
      include 'cparam.inc'
      include 'cwork.inc'
      character*(mfile) file
*-----------------------------------------------------------------------
*
      open (11, file=file,
     &      status='unknown', form='unformatted',
     &      access='direct', recl=lrec(mw))

      write(11,rec=(nio - 1)*mvar + 1) r
      write(11,rec=(nio - 1)*mvar + 2) px
      write(11,rec=(nio - 1)*mvar + 3) py
      write(11,rec=(nio - 1)*mvar + 4) pz
      write(11,rec=(nio - 1)*mvar + 5) e
      if (mvar.gt.5) then
        write(11,rec=(nio - 1)*mvar + 6) bx
        write(11,rec=(nio - 1)*mvar + 7) by
        write(11,rec=(nio - 1)*mvar + 8) bz
      endif
*
      close(11)
      end
************************************************************************
      subroutine read_datav (file, nio)
*
*  Read data from the datavault
*
      include 'cparam.inc'
      character *(mfile) file
      integer nio
*-----------------------------------------------------------------------

      print *,'read_datav called'
      stop
      end
************************************************************************
      subroutine write_datav (nio)
*
*  Write data to datavault.
*
      print *,'write_datav called'
      stop
      end