curs_refresh, doupdate, redrawwin, refresh, wrefresh, wnoutrefresh, wredrawln - Refresh Curses windows and lines
Curses Library (libcurses)
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
reference page for more information
about industry standards and associated tags.
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.
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
is preferred over
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.
The header file <curses.h> automatically includes the header file <stdio.h>.
may be a macro.
All routines return the integer
upon successful completion.
Functions: curses(3), curs_outopts(3)