## Copyright (C) 1996, 1997 John W. Eaton
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, 59 Temple Place - Suite 330, Boston, MA
## 02111-1307, USA.

## usage: dump_prefs (file)
##
## Have Octave dump all the current user preference variables to FILE
## in a format that can be parsed by Octave later.  If FILE is omitted,
## the listing is printed to stdout.

## Author: jwe

function dump_prefs (file)

  if (nargin == 0)
    file = stdout;
  endif

  ## XXX FIXME XXX -- it would be nice to be able to get the list of
  ## built-in variables directly from Octave so that we wouldn't have to
  ## remember to update it each time the list of preference variables
  ## changes

  var_list = ["EDITOR";
	      "EXEC_PATH";
	      "IMAGEPATH";
	      "INFO_FILE";
	      "INFO_PROGRAM";
	      "LOADPATH";
	      "PAGER";
	      "PS1";
	      "PS2";
	      "PS4";
	      "automatic_replot";
	      "beep_on_error";
	      "completion_append_char";
	      "default_eval_print_flag";
	      "default_global_variable_value";
	      "default_return_value";
	      "default_save_format";
	      "define_all_return_values";
	      "do_fortran_indexing";
	      "echo_executing_commands";
	      "empty_list_elements_ok";
	      "fixed_point_format";
	      "gnuplot_binary";
	      "gnuplot_command_end";
	      "gnuplot_command_plot";
	      "gnuplot_command_replot";
	      "gnuplot_command_splot";
	      "gnuplot_command_title";
	      "gnuplot_command_using";
	      "gnuplot_command_with";
	      "gnuplot_has_frames";
	      "gnuplot_has_multiplot";
	      "history_file";
	      "history_size";
	      "ignore_function_time_stamp";
	      "implicit_num_to_str_ok";
	      "implicit_str_to_num_ok";
	      "initialize_global_variables";
	      "max_recursion_depth";
	      "ok_to_lose_imaginary_part";
	      "output_max_field_width";
	      "output_precision";
	      "page_output_immediately";
	      "page_screen_output";
	      "prefer_column_vectors";
	      "print_answer_id_name";
	      "print_empty_dimensions";
	      "print_rhs_assign_val";
	      "propagate_empty_matrices";
	      "resize_on_range_error";
	      "return_last_computed_value";
	      "save_precision";
	      "saving_history";
	      "silent_functions";
	      "split_long_rows";
	      "string_fill_char";
	      "struct_levels_to_print";
	      "suppress_verbose_help_message";
	      "treat_neg_dim_as_zero";
	      "warn_assign_as_truth_value";
	      "warn_divide_by_zero";
	      "warn_function_name_clash";
	      "warn_future_time_stamp";
	      "warn_missing_semicolon";
	      "warn_variable_switch_label";
	      "whitespace_in_literal_matrix"];

  for i = 1:rows(var_list)
    var = deblank (var_list(i,:));
    try
      fprintf (file, "  %s = %s\n", var, type ("-q", var));
    catch
      fprintf (file, "# %s = <no value or error in displaying it>\n", var);
    end_try_catch
  endfor

endfunction
