#### 1.3.5.2 A Sample Command Description

Commands are functions that may be called without surrounding their arguments in parentheses. Command descriptions have a format similar to function descriptions. For example, here is the description for Octave’s `diary` command:

diary
diary on
diary off
diary filename
[status, diaryfile] = diary

  Record a list of all commands and the output they produce, mixed together just as they appear on the terminal.

  Valid options are:

  on

    Start recording a session in a file called `diary` in the current working directory.

  off

    Stop recording the session in the diary file.

  filename

    Record the session in the file named filename.

  With no input or output arguments, `diary` toggles the current diary state.

  If output arguments are requested, `diary` ignores inputs and returns the current status. The boolean status indicates whether recording is on or off, and diaryfile is the name of the file where the session is stored.

  See also: history, evalc.