# 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 win-
           dows, 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  vari-
           ables.

### resize_term

           Most   of   the   work  is  done  by  the  inner  function
           resize_term.  The outer function resizeterm adds bookkeep-
           ing  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 appro-
           priate 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  addi-
           tional interaction with the application.

### 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 win-
           dows 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 real-
           loc may have been interrupted, since it uses  those  func-
           tions.

           If  ncurses  is configured to supply its own SIGWINCH han-
           dler,

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

           o   which is tested in wgetch 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 automati-
               cally.

               Calling resizeterm or resize_term directly from a sig-
               nal  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 SIG-
           WINCH 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)