wnoutrefresh, doupdate - do efficient refresh
The routine updates screens more efficiently than using the routine by
itself. The routine copies the named window to a data structure
referred to as the virtual screen (stdscr). The virtual screen con‐
tains what a program intends to display on the physical terminal
screen. The routine compares the virtual screen to the physical screen
and then does the actual update. These two routines allow multiple
updates with more efficiency than
The routine works by calling and then calling If a programmer wants to
output several windows at once, a series of calls to will result in
alternating calls to and causing several bursts of output to the
screen. If is called first for each window, only needs to be called
once, resulting in only one burst of output. This usually results in
fewer total characters being transmitted and less CPU time used.
The and functions return OK on success and ERR on error.