An Emacs command may require you to answer a yes-or-no question during the course of its execution. Such queries come in two main varieties.
For the first type of yes-or-no query, the prompt ends with ‘(y or n)’. You answer the query by typing a single key, either ‘y’ or ‘n’, which immediately exits the minibuffer and delivers the response. For example, if you type C-x C-w (write-file) to save a buffer, and enter the name of an existing file, Emacs issues a prompt like this:
File ‘foo.el’ exists; overwrite? (y or n)
The second type of yes-or-no query is typically employed if giving
the wrong answer would have serious consequences; it thus features a
longer prompt ending with ‘(yes or no)’. For example, if you
invoke C-x k (
kill-buffer) on a file-visiting buffer with
unsaved changes, Emacs activates the minibuffer with a prompt like
Buffer foo.el modified; kill anyway? (yes or no)
To answer, you must type ‘yes’ or ‘no’ into the minibuffer, followed by RET.
With both types of yes-or-no query the minibuffer behaves as described in the previous sections; you can recenter the selected window with C-l, scroll that window (C-v or PageDown scrolls forward, M-v or PageUp scrolls backward), switch to another window with C-x o, use the history commands M-p and M-n, etc. Type C-g to dismiss the query, and quit the minibuffer and the querying command (see Quitting and Aborting).