### 2.4 Command Line Editing

Octave uses the GNU Readline library to provide an extensive set of command-line editing and history features. Only the most common features are described in this manual. In addition, all of the editing functions can be bound to different key strokes at the user’s discretion. This manual assumes no changes from the default Emacs bindings. See the GNU Readline Library manual for more information on customizing Readline and for a complete feature list.

To insert printing characters (letters, digits, symbols, etc.), simply type the character. Octave will insert the character at the cursor and advance the cursor forward.

Many of the command-line editing functions operate using control characters. For example, the character `Control-a` moves the cursor to the beginning of the line. To type `C-a`, hold down `CTRL` and then press `a`. In the following sections, control characters such as `Control-a` are written as `C-a`.

Another set of command-line editing functions use Meta characters. To type `M-u`, hold down the `META` key and press `u`. Depending on the keyboard, the `META` key may be labeled `ALT` or even `WINDOWS`. If your terminal does not have a `META` key, you can still type Meta characters using two-character sequences starting with `ESC`. Thus, to enter `M-u`, you would type `ESC` `u`. The `ESC` character sequences are also allowed on terminals with real Meta keys. In the following sections, Meta characters such as `Meta-u` are written as `M-u`.