NAME

       is_term_resized, resize_term, resizeterm - change the curses terminal size

SYNOPSIS

       #include <curses.h>

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

DESCRIPTION

       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  programs  running  in  an  X  Window
       terminal (e.g., xterm).

   resizeterm
       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.

   resize_term
       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 appropriate 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.

   is_term_resized
       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.

RETURN VALUE

       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 memory for the windows.

NOTES

       While  these  functions  are  intended  to  be used to support a signal handler (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,

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

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

       •   in turn, calling the resizeterm function,

       •   which ungetch's a KEY_RESIZE which will be read on the next call to wgetch.

           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 resize 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 system.  Thus, even if a SIGWINCH is received,
       no screen size change may be recorded.

PORTABILITY

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

       •   exiting curses with endwin(3X) and

       •   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).

SEE ALSO

       getch(3NCURSES), curses_variables(3NCURSES), wresize(3NCURSES).

AUTHOR

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

                                                                             resizeterm(3NCURSES)