function list_hdf_field_names, file_name, COUNT=count

    list = ""
    command = "vshow "+ '"'+file_name+'"' + " | grep entries | grep Var"
    spawn, command, lines
;breaki
    if lines[0] eq '' then begin ; this is perhaps an unpacked hdf5 format ? 
       print, 'trying h5ls next'
       command = 'h5ls ' + '"' +file_name+'"'
       spawn, command, lines
       if N_elements(lines) eq 1 then begin ; don't know what to do
          print, 'could not find field names in file:', file_name
          print, ' do you have vshow (part of hdf4)  and h5ls in your path ? '
          breaki
          return, ["no fields found"]
       endif 
       for i=0,N_elements(lines)-1 do begin
          hl = strmid(lines[i],0,strpos(lines[i], ' ')+1)
          if hl ne '' and total(hl eq list) eq 0 then list = [list, hl]
          print, '>'+hl+'<'
       endfor
    endif else begin
       for i=0,N_elements(lines)-1 do begin
          lines[i] = strmid(lines[i],strpos(lines[i], '(')+1)
          curis = strpos(lines[i], '{')
          hl = strtrim(strmid(lines[i], 0, curis),2)
          if hl ne '' and total(hl eq list) eq 0 then list = [list, hl]
          print, '>'+hl+'<'
       endfor
    endelse
    list = list[1:*]

    if ARG_PRESENT(COUNT) then count=N_elements(list)
    print, 'read ', N_elements(list), ' data labels from ', file_name
;breaki
    if N_elements(list) gt 0 then return, list ; else try more conventional way 

; return list of strings of labels in hdf file 
; if count is a named variable it returns the number of data sets 
  list = ''
  print, 'list:', file_name
  dummy = FindFile(file_name , COUNT = exist)  
  if dummy(0) eq '' then BEGIN
      print, 'read_hdf: the file "', file_name, '" does not exist!'
      RETURN, list
  ENDIF
  sd_id = HDF_SD_START(file_name[0], /READ)
  HDF_SD_FILEINFO, sd_id, NumSDS, attributes
  count = 0L
  n = 0L
  FOR i=1L,NumSDS DO BEGIN
      r=0. & l=0.
      sds_id = HDF_SD_SELECT(sd_id, n)
      WHILE (HDF_SD_ISCOORDVAR(sds_id)) DO BEGIN
        HDF_SD_ENDACCESS, sds_id
        n = n + 1
        sds_id = HDF_SD_SELECT(sd_id, n)
      ENDWHILE
      n = n + 1
      HDF_SD_GETINFO, sds_id, label = l, dims=d, type=t
      print, i, ' ', l, size(l)
      if (l NE '') then begin 
          list = [list, l]
          count = count + 1
      endif
      HDF_SD_ENDACCESS, sds_id
  ENDFOR
  HDF_SD_END, sd_id
  if (N_ELEMENTS(list) gt 1) THEN $
    RETURN, list[1:*] $
  ELSE BEGIN
      print, 'having trouble reading labels in ',file_name
      print, 'returning dummy list'
      list = 'No labels read ...';
   ENDELSE
  return, ''
END