Linux · Emacs

You mistype a keystroke and get a menu, then hit Ctrl+X Ctrl+C by accident with unsaved work. How do you exit Emacs, and what limit does its undo have?

Answer locked. Get the free KnowCard app to reveal it — plus spaced-repetition review so it actually sticks.

This is one card from the KnowCard library — thousands more across SAP, Linux, Python and more. In the app you get the answer, AI explanations, and cards that come back right before you would forget them. Free to start on iOS, Android or the web.

More in Emacs

The Emacs name is often mocked as "Escape Meta Alt Control Shift" because of its dense key sequences. What does the acronym actually stand for, and what is Emacs beyond a text editor?

In Emacs, both loading and saving a file start with the same two-key prefix. What are the three core commands for opening a file, saving it, and saving it under a new name?

You started typing an Emacs command, or hit Esc by mistake, and Emacs is now waiting for more input. How do you cancel out of a half-entered command?

A newcomer wants Emacs to teach itself and to look up what a key does. Which help commands start the built-in tutorial, list all key bindings, and describe a command?

You open a .c file and Emacs auto-indents lines in ways you don't want. What is the rule about how many major vs minor modes can be active, and how do you fall back to a plain mode?

Besides menus and key shortcuts, Emacs lets you invoke any command by its full name. How do you do that, and what conveniences help you type or recall the name?

Start learning today

Free to start — download the app or use it in your browser.