### 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. Please see The GNU Readline Library manual for more information.

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. On some terminals, you type `M-u` by holding down <META> and pressing <u>. If your terminal does not have a <META> key, you can still type Meta charcters using two-character sequences starting with `ESC`. Thus, to enter `M-u`, you could 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`.