subroutine GDNcVarPutAttrChar(var, name, value, xtype, err)
  use gtdata_netcdf_types, only: GD_NC_VARIABLE, GD_NC_VARIABLE_ENTRY
  use gtdata_netcdf_internal, only: vtable_lookup
  use gtdata_netcdf_file_generic, only: GDNcFileDefineMode
  use netcdf_f77, only: NF_PUT_ATT_TEXT, NF_NOERR, NF_DEL_ATT, NF_ENOTINDEFINE, NF_GLOBAL
  use dc_url, only: GT_PLUS
  use dc_error
  use dc_string, only: get_array
  use gtdata_netcdf_generic, only: put_attr
  implicit none
  type(GD_NC_VARIABLE), intent(in):: var
  character(len = *), intent(in):: name
  character(len = *), intent(in):: value
  character(len = *), intent(in), optional:: xtype
  logical, intent(out), optional:: err
  integer, pointer:: ip(:)
  real, pointer:: rp(:)
  double precision, pointer:: dp(:)
  integer:: stat
  type(GD_NC_VARIABLE_ENTRY):: ent
continue
  stat = vtable_lookup(var, ent)
  if (stat /= NF_NOERR) goto 999
  if (len(value) == 0) then
    if (name(1:1) == GT_PLUS) then
      stat = nf_del_att(ent % fileid, NF_GLOBAL, name = name(2:))
    else
      stat = nf_del_att(ent % fileid, ent % varid, name = name)
    endif
    goto 999
  endif
  if ( present(xtype) ) then
    select case(xtype)
    case("INTEGER", "integer", "int")
      goto 200
    case("REAL", "real", "float")
      goto 300
    case("DOUBLEPRECISION", "DOUBLE", "double")
      goto 400
    end select
  end if

  stat = GDNcFileDefineMode( ent % fileid )
  if (stat /= NF_NOERR) goto 999
  if (name(1:1) == GT_PLUS) then
    stat = nf_put_att_text(ent % fileid, NF_GLOBAL, name = name(2:), len = len_trim(value), text = trim(value) )
  else
    stat = nf_put_att_text(ent % fileid, ent % varid, name = name, len = len_trim(value), text = trim(value) )
  endif

999 continue
  call StoreError(stat, 'GDNcVarPutAttrChar', err, cause_c=name)
  return

200 continue
  call get_array(ip, value)
  if (associated(ip)) then
    call put_attr(var, name, ip, err)
    deallocate(ip)
  endif
  return

300 continue
  call get_array(rp, value)
  if (associated(rp)) then
    call put_attr(var, name, rp, err)
    deallocate(rp)
  endif
  return

400 continue
  call get_array(dp, value)
  if (associated(dp)) then
    call put_attr(var, name, dp, err)
    deallocate(dp)
  endif
  return
end subroutine GDNcVarPutAttrChar