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 doup‐
date()) must be called to get any output on the terminal, as other rou‐
tines 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() rou‐
tine 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 doup‐
date(), which compares the virtual screen to the physical screen and
does the actual update. If the programmer wishes to output several win‐
dows at once, a series of calls to wrefresh() results in alternating
calls to wnoutrefresh() and doupdate(), causing several bursts of out‐
put 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 com‐
munication 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(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Unsafe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOcurs_outopts(3CURSES), curses(3CURSES), attributes(5)NOTES
The header <curses.h> automatically includes the headers <stdio.h> and
<unctrl.h>.
Note that refresh() and redrawwin() may be macros.
SunOS 5.10 31 Dec 1996 curs_refresh(3CURSES)
