# resizeterm 3x

    resizeterm(3x)                                                  resizeterm(3x)

## 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 pro-
           grams 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.   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 win-
           dows.  However, due to the calling convention of pads, it is not possi-
           ble  to  resize  these without additional interaction with the applica-
           tion.

### 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  mem-
           ory for the windows.

## NOTES

           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
               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  sys-
           tem.   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

           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).

## SEE ALSO

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

## AUTHOR

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

                                                                    resizeterm(3x)