Provided by: ncurses-doc_6.5+20251123-1_all bug

NAME

       newwin,  delwin, mvwin, subwin, derwin, mvderwin, dupwin, wsyncup, syncok, wcursyncup, wsyncdown - create
       and manipulate curses windows

SYNOPSIS

       #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);

DESCRIPTION

   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.

RETURN VALUE

       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(3NCURSES)  or
       newterm(3NCURSES).

NOTES

       syncok may be implemented as a macro.

       Calling syncup on a window and making many small changes to it could degrade performance.

PORTABILITY

       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.

SEE ALSO

       ncurses(3NCURSES), initscr(3NCURSES), refresh(3NCURSES), touch(3NCURSES), curses_variables(3NCURSES)

ncurses 6.5                                        2025-08-23                                   window(3NCURSES)