Content-type: text/html Man page of curs_refresh

curs_refresh

Section: C Library Functions (3)
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NAME

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

SYNOPSIS

#include <curses.h>

int doupdate( void ); int redrawwin( WINDOW *win ); int refresh( void ); int wrefresh( WINDOW *win ); int wnoutrefresh( WINDOW *win ); int wredrawln( WINDOW *win, int beg_line, int num_lines );
 

LIBRARY

Curses Library (libcurses)
 

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

doupdate, refresh, wrefresh, wnoutrefresh:  XPG4, XPG4-UNIX

redrawwin, wredrawln:  XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.
 

DESCRIPTION

Applications must call the refresh and wrefresh routines (or the wnoutrefresh and doupdate routines) to get any output on the terminal. Other Curses routines only manipulate data structures. The wrefresh routine copies the specified window to the physical terminal screen, taking into account what is already there in order to do optimizations. The refresh routine does the same operation on stdscr. Unless leaveok is enabled, Curses leaves the physical cursor of the terminal 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 specified 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 wants 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. If the program first calls wnoutrefresh for each window, it is then possible to call doupdate once, resulting in only one burst of output, with transmission of fewer characters overall and less use of CPU time. If the win argument to wrefresh is the global variable curscr, Curses immediately clears the screen and repaints the window from scratch.

The redrawwin routine tells Curses that some screen lines are corrupted and should be thrown away before anything is written over them. This routine could be used in programs, such as editors, that need 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. In this case, redrawing only several lines offers the possibility that they would appear unblemished.
 

NOTES

The header file <curses.h> automatically includes the header file <stdio.h>.

Note that refresh may be a macro.
 

RETURN VALUES

All routines return the integer ERR upon failure and OK upon successful completion.
 

SEE ALSO

Functions: curses(3), curs_outopts(3)

Others: standards(5)


 

Index

NAME
SYNOPSIS
LIBRARY
STANDARDS
DESCRIPTION
NOTES
RETURN VALUES
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 02:42:11 GMT, October 02, 2010