On most systems, Octave is started with the shell command ‘octave’. This starts the graphical user interface. The central window in the GUI is the Octave command-line interface. In this window 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 then only the command prompt appears in the same window that was running a shell. In either 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.