CURS_REFRESH(3CURSES) Curses Library Functions CURS_REFRESH(3CURSES)

NAME

curs_refresh, refresh, wrefresh, wnoutrefresh, doupdate, redrawwin,
wredrawln - refresh curses windows and lines

SYNOPSIS

cc [ flag ... ] file ... -lcurses [ library ... ]
#include <curses.h>

int refresh(void);


int wrefresh(WINDOW *win);


int wnoutrefresh(WINDOW *win);


int doupdate(void);


int redrawwin(WINDOW *win);


int wredrawln(WINDOW *win, int beg_line, int num_lines);

DESCRIPTION

The refresh() and wrefresh() routines (or wnoutrefresh() and doupdate())
must be called to get any output on the terminal, as other routines
merely manipulate data structures. The routine wrefresh() copies the
named window to the physical terminal screen, taking into account what is
already there in order to do optimizations. The refresh() routine is the
same, using stdscr as the default window. Unless leaveok() has been
enabled, the physical cursor of the terminal is left at the location of
the cursor for that window.


The wnoutrefresh() and doupdate() routines allow multiple updates with
more efficiency than wrefresh() alone. In addition to all the window
structures, curses keeps two data structures representing the terminal
screen: a physical screen, describing what is actually on the screen, and
a virtual screen, describing what the programmer wants to have on the
screen.


The routine wrefresh() works by first calling wnoutrefresh(), which
copies the named window to the virtual screen, and then calling
doupdate(), which compares the virtual screen to the physical screen and
does the actual update. If the programmer wishes to output several
windows at once, a series of calls to wrefresh() results in alternating
calls to wnoutrefresh() and doupdate(), causing several bursts of output
to the screen. By first calling wnoutrefresh() for each window, it is
then possible to call doupdate() once, resulting in only one burst of
output, with fewer total characters transmitted and less CPU time used.
If the win argument to wrefresh() is the global variable curscr, the
screen is immediately cleared and repainted from scratch.


The redrawwin() routine indicates to curses that some screen lines are
corrupted and should be thrown away before anything is written over them.
These routines could be used for programs such as editors, which want a
command to redraw some part of the screen or the entire screen. The
routine redrawln() is preferred over redrawwin() where a noisy
communication line exists and redrawing the entire window could be
subject to even more communication noise. Just redrawing several lines
offers the possibility that they would show up unblemished.

RETURN VALUES

All routines return the integer ERR upon failure and an integer value
other than ERR upon successful completion.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | Unsafe |
+---------------+-----------------+

SEE ALSO

curs_outopts(3CURSES), curses(3CURSES), attributes(7)

NOTES

The header <curses.h> automatically includes the headers <stdio.h> and
<unctrl.h>.


Note that refresh() and redrawwin() may be macros.


December 31, 1996 CURS_REFRESH(3CURSES)