### 7.4 Summary of Built-in Variables

Here is a summary of all of Octave's built-in variables along with cross references to additional information and their default values. In the following table octave-home stands for the root directory where all of Octave is installed (the default is `/usr/local`, version stands for the Octave version number (for example, 3.0.5) and arch stands for the type of system for which Octave was compiled (for example, `x86_64-unknown-linux-gnu`).

`EDITOR`
  See Commands For History.

  Default value: `"emacs"`.

`EXEC_PATH`
  See Controlling Subprocesses.

  Default value: `":$PATH"`.

`OCTAVE_HOME`
  Default value: `"/usr/local"`.
`PAGER`
  See Input and Output.

  Default value: `"less", or "more"`.

`PS1`
  See Customizing the Prompt.

  Default value: `"\s:\#> "`.

`PS2`
  See Customizing the Prompt.

  Default value: `"> "`.

`PS4`
  See Customizing the Prompt.

  Default value: `"+ "`.

`beep_on_error`
  See Errors and Warnings.

  Default value: 0.

`completion_append_char`
  See Commands For Completion.

  Default value: `" "`.

`default_save_options`
  See Simple File I/O.

  Default value: `"ascii"`.

`crash_dumps_octave_core`
  See Simple File I/O.

  Default value: 1.

`fixed_point_format`
  See Matrices.

  Default value: 0.

`gnuplot_binary`
  See Three-Dimensional Plotting.

  Default value: `"gnuplot"`.

`history_file`
  See Commands For History.

  Default value: `"~/.octave_hist"`.

`history_size`
  See Commands For History.

  Default value: 1024.

`ignore_function_time_stamp`
  See Function Files.

  Default value: `"system"`.

`max_recursion_depth`
  See Recursion.

  Default value: 256.

`output_max_field_width`
  See Matrices.

  Default value: 10.

`output_precision`
  See Matrices.

  Default value: 5.

`page_screen_output`
  See Input and Output.

  Default value: 1.

`print_answer_id_name`
  See Terminal Output.

  Default value: 1.

`print_empty_dimensions`
  See Empty Matrices.

  Default value: 1.

`return_last_computed_value`
  See Returning From a Function.

  Default value: 0.

`save_precision`
  See Simple File I/O.

  Default value: 17.

`saving_history`
  See Commands For History.

  Default value: 1.

`sighup_dumps_octave_core`
  See Simple File I/O.

  Default value: 1.

`sigterm_dumps_octave_core`
  See Simple File I/O.

  Default value: 1.

`silent_functions`
  See Defining Functions.

  Default value: 0.

`split_long_rows`
  See Matrices.

  Default value: 1.

`struct_levels_to_print`
  See Data Structures.

  Default value: 2.

`suppress_verbose_help_message`
  See Getting Help.

  Default value: 1.