— Variable: cursor-in-echo-area

This variable controls where the cursor appears when a message is displayed in the echo area. If it is non-nil, then the cursor appears at the end of the message. Otherwise, the cursor appears at point—not in the echo area at all.

The value is normally nil; Lisp programs bind it to t for brief periods of time.

— Variable: echo-area-clear-hook

This normal hook is run whenever the echo area is cleared—either by (message nil) or for any other reason.

— User Option: echo-keystrokes

This variable determines how much time should elapse before command characters echo. Its value must be a number, and specifies the number of seconds to wait before echoing. If the user types a prefix key (such as C-x) and then delays this many seconds before continuing, the prefix key is echoed in the echo area. (Once echoing begins in a key sequence, all subsequent characters in the same key sequence are echoed immediately.)

If the value is zero, then command input is not echoed.

— Variable: message-truncate-lines

Normally, displaying a long message resizes the echo area to display the entire message. But if the variable message-truncate-lines is non-nil, the echo area does not resize, and the message is truncated to fit it.