Command History Functions

Octave provides three functions for viewing, editing, and re-running chunks of commands from the history list.

The function history displays a list of commands that you have executed. It also allows you to write the current history to a file for safe keeping, and to replace the history list with the commands stored in a named file. Valid arguments are:

-w file

Write the current history to the named file. If the name is omitted, use the default history file (normally `~/.octave_hist').

-r file

Read the named file, replacing the current history list with its contents. If the name is omitted, use the default history file (normally `~/.octave_hist').

N

Only display the most recent N lines of history.

-q

Don't number the displayed lines of history. This is useful for cutting and pasting commands if you are using the X Window System.

For example, to display the five most recent commands that you have typed without displaying line numbers, use the command `history -q 5'.

The function edit_history allows you to edit a block of commands from the history list using the editor named by the environment variable EDITOR, or the default editor (normally vi). It is often more convenient to use edit_history to define functions rather than attempting to enter them directly on the command line. By default, the block of commands is executed as soon as you exit the editor. To avoid executing any commands, simply delete all the lines from the buffer before exiting the editor.

The edit_history command takes two optional arguments specifying the history numbers of first and last commands to edit. For example, the command

edit_history 13

extracts all the commands from the 13th through the last in the history list. The command

edit_history 13 169

only extracts commands 13 through 169. Specifying a larger number for the first command than the last command reverses the list of commands before placing them in the buffer to be edited. If both arguments are omitted, the previous command in the history list is used.

The command run_history is like edit_history, except that the editor is not invoked, and the commands are simply executed as they appear in the history list.

The diary command allows you to create a list of all commands and the output they produce, mixed together just as you see them on your terminal.

For example, the command

diary on

tells Octave to start recording your session in a file called `diary' in your current working directory. To give Octave the name of the file write to, use the a command like

diary my-diary.txt

Then Octave will write all of your commands to the file `my-diary.txt'.

To stop recording your session, use the command

diary off

Without any arguments, diary toggles the current diary state.