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resizeterm(3X)							resizeterm(3X)

       is_term_resized,	 resize_term,  resizeterm - change the curses terminal

       #include	<curses.h>

       bool is_term_resized(int	lines, int columns);
       int resize_term(int lines, int columns);
       int resizeterm(int lines, int columns);

       This is an extension to the curses library.  It provides	callers	with a
       hook into the ncurses data to resize windows, primarily for use by pro-
       grams running in	an X Window terminal (e.g., xterm).

       The function resizeterm resizes the standard and	current	windows	to the
       specified  dimensions,  and  adjusts other bookkeeping data used	by the
       ncurses library that record the window dimensions such as the LINES and
       COLS variables.

       Most  of	the work is done by the	inner function resize_term.  The outer
       function	resizeterm adds	bookkeeping for	the SIGWINCH handler, as  well
       as repainting the soft-key area (see slk_touch(3X)).

       When  resizing  the windows, resize_term	blank-fills the	areas that are
       extended.  The calling application should fill in these areas with  ap-
       propriate data.

       The  resize_term	function attempts to resize all	windows.  However, due
       to the calling convention of pads, it is	not possible to	 resize	 these
       without additional interaction with the application.

       When  resizing  windows,	 resize_term  recursively  adjusts subwindows,
       keeping them within the updated parent window's limits.	If a top-level
       window  happens	to extend to the screen's limits, then on resizing the
       window, resize_term will	keep the window	extending to the corresponding
       limit, regardless of whether the	screen has shrunk or grown.

       A support function is_term_resized is provided so that applications can
       check if	the resize_term	function would modify the  window  structures.
       It returns TRUE if the windows would be modified, and FALSE otherwise.

       Except  as  noted,  these functions return the integer ERR upon failure
       and OK on success.  They	will fail if either of the dimensions are less
       than  or	equal to zero, or if an	error occurs while (re)allocating mem-
       ory for the windows.

       While these functions are intended to be	used to	support	a signal  han-
       dler  (i.e., for	SIGWINCH), care	should be taken	to avoid invoking them
       in a context where malloc or realloc may	have been  interrupted,	 since
       it uses those functions.

       If ncurses is configured	to supply its own SIGWINCH handler,

       o   on receipt of a SIGWINCH, the handler sets a	flag

       o   which is tested in wgetch(3X) and doupdate,

       o   in turn, calling the	resizeterm function,

       o   which ungetch's a KEY_RESIZE	which will be read on the next call to

	   The KEY_RESIZE alerts an  application  that	the  screen  size  has
	   changed,  and  that it should repaint special features such as pads
	   that	cannot be done automatically.

	   Calling resizeterm or resize_term directly from a signal handler is
	   unsafe.   This indirect method is used to provide a safe way	to re-
	   size	the ncurses data structures.

       If the environment variables LINES or COLUMNS are set,  this  overrides
       the  library's  use of the window size obtained from the	operating sys-
       tem.  Thus, even	if a SIGWINCH is received, no screen size  change  may
       be recorded.

       It is possible to resize	the screen with	SVr4 curses, by

       o   exiting curses with endwin(3X) and

       o   resuming using refresh(3X).

       Doing that clears the screen and	is visually distracting.

       This  extension	of ncurses was introduced in mid-1995.	It was adopted
       in NetBSD curses	(2001) and PDCurses (2003).

       curs_getch(3X), curs_variables(3X), wresize(3X).

       Thomas Dickey (from an equivalent function  written  in	1988  for  BSD



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