curs_refresh(3X)               DG/UX R4.11MU05              curs_refresh(3X)


NAME
       cursrefresh:  refresh, wrefresh, wnoutrefresh, doupdate, redrawwin,
       wredrawln - 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 begline, int numlines);

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

NOTES
       The header file <curses.h> automatically includes the header files
       <stdio.h> and <unctrl.h>.

       Note that refresh and redrawwin may be macros.

SEE ALSO
       curses(3X), cursoutopts(3X).


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