GNU Emacs Lisp Reference Manual

35.1: Refreshing the Screen

The function redraw-frame redisplays the entire contents of a given frame. See Frames.

Function: redraw-frame frame

This function clears and redisplays frame frame.

Even more powerful is redraw-display:

Command: redraw-display

This function clears and redisplays all visible frames.

Processing user input takes absolute priority over redisplay. If you call these functions when input is available, they do nothing immediately, but a full redisplay does happen eventually---after all the input has been processed.

Normally, suspending and resuming Emacs also refreshes the screen. Some terminal emulators record separate contents for display-oriented programs such as Emacs and for ordinary sequential display. If you are using such a terminal, you might want to inhibit the redisplay on resumption.

Variable: no-redraw-on-reenter

This variable controls whether Emacs redraws the entire screen after it has been suspended and resumed. Non-nil means yes, nil means no.