resizeterm(3) UNIX Programmer's Manual resizeterm(3)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 termi-
nal (e.g., xterm). The function resizeterm resizes the stan-
dard and current windows to the specified dimensions, and
adjusts other bookkeeping data used by the ncurses library
that record the window dimensions.
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 appli-
cation should fill in these areas with appropriate data. The
resize_term function attempts to resize all windows. How-
ever, due to the calling convention of pads, it is not pos-
sible to resize these without additional interaction with
the application.
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 notes, these function 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,
the resizeterm function ungetch's a KEY_RESIZE which will be
read on the next call to getch. This is used to alert an
application that the screen size has changed, and that it
should repaint special features such as pads that cannot be
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resizeterm(3) UNIX Programmer's Manual resizeterm(3)
done automatically.
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. In that case, no
KEY_RESIZE is queued for the next call to getch; an ERR will
be returned instead.
SEE ALSOwresize(3).
AUTHOR
Thomas Dickey (from an equivalent function written in 1988
for BSD curses).
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