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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | PORTABILITY | SEE ALSO | COLOPHON |
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curs_window(3X) Library calls curs_window(3X)
newwin, delwin, mvwin, subwin, derwin, mvderwin, dupwin, wsyncup,
syncok, wcursyncup, wsyncdown - create and manipulate curses
windows
#include <curses.h>
WINDOW * newwin(
int nlines, int ncols,
int begin_y, int begin_x);
int delwin(WINDOW * win);
int mvwin(WINDOW * win, int y, int x);
WINDOW * subwin(WINDOW * orig,
int nlines, int ncols,
int begin_y, int begin_x);
WINDOW * derwin(WINDOW * orig,
int nlines, int ncols,
int begin_y, int begin_x);
int mvderwin(WINDOW * win, int par_y, int par_x);
WINDOW * dupwin(WINDOW * win);
void wsyncup(WINDOW * win);
int syncok(WINDOW * win, bool bf);
void wcursyncup(WINDOW * win);
void wsyncdown(WINDOW * win);
newwin
Calling newwin creates and returns a pointer to a new window with
the given number of lines and columns. The upper left-hand corner
of the window is at
line begin_y,
column begin_x
If either nlines or ncols is zero, they default to
LINES - begin_y and
COLS - begin_x.
A new full-screen window is created by calling newwin(0,0,0,0).
Regardless of the function used for creating a new window (e.g.,
newwin, subwin, derwin, newpad), rather than a duplicate (with
dupwin), all of the window modes are initialized to the default
values. The following functions set a window's modes after it is
created:
idcok, idlok, immedok, keypad, leaveok, nodelay, notimeout,
scrollok, setscrreg, syncok, wbkgdset, wbkgrndset, and
wtimeout.
delwin
Calling delwin deletes the named window, freeing all memory
associated with it (it does not actually erase the window's screen
image). Subwindows must be deleted before the main window can be
deleted.
mvwin
Calling mvwin moves the window so that the upper left-hand corner
is at position (x, y). If the move would cause the window to be
off the screen, it is an error and the window is not moved.
Moving subwindows is allowed, but should be avoided.
subwin
Calling subwin creates and returns a pointer to a new window with
the given number of lines, nlines, and columns, ncols. The window
is at position (begin_y, begin_x) on the screen. The subwindow
shares memory with the window orig, its ancestor, so that changes
made to one window will affect both windows. When using this
routine, it is necessary to call touchwin or touchline on orig
before calling wrefresh on the subwindow.
derwin
Calling derwin is the same as calling subwin, except that begin_y
and begin_x are relative to the origin of the window orig rather
than the screen. There is no difference between the subwindows
and the derived windows.
mvderwin
Calling mvderwin moves a derived window (or subwindow) inside its
parent window. The screen-relative parameters of the window are
not changed. This routine is used to display different parts of
the parent window at the same physical position on the screen.
dupwin
Calling dupwin creates an exact duplicate of the window win.
wsyncup
Calling wsyncup touches all locations in ancestors of win that are
changed in win. If syncok is called with second argument TRUE
then wsyncup is called automatically whenever there is a change in
the window.
wsyncdown
The wsyncdown routine touches each location in win that has been
touched in any of its ancestor windows. This routine is called by
wrefresh, so it should almost never be necessary to call it
manually.
wcursyncup
The routine wcursyncup updates the current cursor position of all
the ancestors of the window to reflect the current cursor position
of the window.
Functions that return integers return ERR upon failure and OK upon
success.
Functions that return pointers return a null pointer on failure.
ncurses defines several error conditions.
• delwin returns ERR if win is a null pointer, or if it is the
parent of another window.
ncurses maintains a list of windows, and checks that the
pointer passed to delwin is one that it created, returning ERR
if it was not.
• derwin returns ERR if orig is a null pointer, or if any of the
ordinate or dimension arguments is negative, or if the
resulting window does not fit inside the parent window.
• dupwin returns ERR if win is a null pointer.
• mvderwin returns ERR if win is a null pointer, or if any part
of the window would be placed off-screen.
• mvwin returns ERR if win is a null pointer, if win is a pad,
or if any part of the window would be placed off-screen.
• newwin returns ERR if any of its arguments is negative.
• subwin returns ERR if orig is a null pointer, or if any of the
ordinate or dimension arguments is negative, or if the
resulting window does not fit inside the parent window.
• syncok returns ERR if win is a null pointer.
Functions that return a window pointer fail if memory allocation
for their data structures fails.
All of these functions fail if the screen has not been
initialized; see initscr(3X) or newterm(3X).
syncok may be implemented as a macro.
Calling syncup on a window and making many small changes to it
could degrade performance.
X/Open Curses Issue 4 describes these functions. It specifies no
error conditions for delwin, derwin, dupwin, newwin, mvderwin, or
syncok.
For functions returning integers (except delwin), SVr4 describes a
successful return value only as “an integer value other than ERR”.
Regarding delwin, X/Open Curses states that
[t]he application must delete subwindows before deleting
the main window.
If delwin is asked to delete a parent window, it can succeed only
if the curses library keeps a list of its subwindows. SVr4 curses
kept a count of the number of subwindows rather than a list. It
simply returned ERR when asked to delete a subwindow. Solaris
X/Open curses (xcurses) does not make even that check, and will
delete a parent window that still has subwindows. PDCurses also
behaves this way.
ncurses 4.0 (1996) and later maintains a list of windows for each
screen to ensure that a window has no subwindows before allowing
its deletion. NetBSD curses has followed suit since 2003.
SVr4 curses documentation is unclear about what wsyncup and
wsyncdown actually do. It seems to imply that they are supposed
to touch only those lines that are affected by changes to a
window's ancestors. The description and behavior of these
functions in ncurses is patterned on the X/Open Curses standard;
this approach may result in slower updates.
curses(3X), curs_initscr(3X), curs_refresh(3X), curs_touch(3X),
curs_variables(3X)
This page is part of the ncurses (new curses) project.
Information about the project can be found at
⟨https://invisible-island.net/ncurses/ncurses.html⟩. If you have a
bug report for this manual page, send it to bug-ncurses@gnu.org.
This page was obtained from the tarball ncurses-6.6.tar.gz fetched
from ⟨https://ftp.gnu.org/gnu/ncurses/⟩ on 2026-01-16. If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for the
page, or you have corrections or improvements to the information
in this COLOPHON (which is not part of the original manual page),
send a mail to man-pages@man7.org
ncurses @NCURSES_MAJOR@.@NCU... 2025-08-23 curs_window(3X)
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HTML rendering created 2026-01-16 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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