8.8 Yes or No Prompts
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
this:
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).