pro dustem_show_sysvar,file=file

  if keyword_set(file) then OPENW, 2, file
  
  help,/sys,out=sysvar
  for i=0,n_elements(sysvar)-1 do begin
     this_line=strsplit(sysvar[i],"!",/ext)
     for j=0,n_elements(this_line)-1 do begin
        print,"!"+this_line[j]
        if keyword_set(file) then printf,2,"!"+this_line[j]
     endfor
     
  endfor

     if keyword_set(file) then close, 2

end