### 1.1 Running Octave

On most systems, Octave is started with the shell command ‘`octave`’. This, by default, starts the graphical user interface (GUI). The central window in the GUI is the Octave command-line interface. Octave displays an initial message and then a prompt indicating it is ready to accept input. If you have chosen the traditional command-line interface only the command prompt appears. In any case, you can immediately begin typing Octave commands.

If you get into trouble, you can usually interrupt Octave by typing `Control-C` (written `C-c` for short). `C-c` gets its name from the fact that you type it by holding down `CTRL` and then pressing `c`. Doing this will normally return you to Octave’s prompt.

To exit Octave, type `quit`, or `exit` at the Octave prompt.

On systems that support job control, you can suspend Octave by sending it a `SIGTSTP` signal, usually by typing `C-z`.