wrefresh

curs_refresh(3X)					     curs_refresh(3X)



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

SYNOPSIS
       #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  actual  output to 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 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 phrase "copies the named window to the virtual  screen"  above  is
       ambiguous.   What actually happens is that all touched (changed) lines
       in the window are copied to the virtual screen.	This affects programs
       that  use  overlapping  windows; it means that if two windows overlap,
       you can refresh them in either order and the overlap  region  will  be
       modified	 only when it is explicitly changed.  (But see the section on
       PORTABILITY below for a warning about exploiting this behavior.)

       The wredrawln routine indicates to curses that some screen  lines  are
       corrupted  and  should  be thrown away before anything is written over
       them.  It touches the indicated lines  (marking	them  changed).	  The
       routine redrawwin() touches the entire window.

RETURN VALUE
       Routines	 that return an integer return ERR upon failure, and OK (SVr4
       only specifies "an integer value other than ERR") upon successful com-
       pletion.

NOTES
       Note that refresh and redrawwin may be macros.

PORTABILITY
       The XSI Curses standard, Issue 4 describes these functions.

       Whether	wnoutrefresh()	copies	to the virtual screen the entire con-
       tents of a window or just its changed portions has  never  been	well-
       documented  in historic curses versions (including SVr4).  It might be
       unwise to rely on either behavior in programs that might	 have  to  be
       linked  with  other  curses  implementations.   Instead, you can do an
       explicit touchwin() before the wnoutrefresh()  call  to	guarantee  an
       entire-contents copy anywhere.

SEE ALSO
       curses(3X), curs_outopts(3X)



							     curs_refresh(3X)