program cloudsat_vdata
  implicit none
!
  character*(64) :: hdffile, vdata_name, fields, interlace

  integer(4) :: hopen, vfstart, vsffnd, vsfatch, vsfinq, vsfread, hclose

  integer :: istat, vdata_ref, vdata_id, num_rec, vdata_size, n_scan
  integer :: file_id

  real, allocatable, dimension(:) :: lon, lat
!
  call getarg(1,hdffile)
  if(iargc() /= 1) call exit(1)
!
  file_id = hopen(hdffile,1,0)
!
  istat = vfstart(file_id)
!
  vdata_ref = vsffnd(file_id,"Longitude")
  vdata_id  = vsfatch(file_id,vdata_ref,"r")
  istat = vsfinq(vdata_id,num_rec,interlace,fields,vdata_size,vdata_name)
  n_scan = num_rec
  allocate(lon(n_scan))
  istat = vsfread(vdata_id,lon,n_scan,interlace)
! 
  istat = hclose(file_id)
!
  write(*,*) lon
!
  deallocate(lon)
!
end program cloudsat_vdata