- change the
curses terminal size
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
data to resize windows, primarily for use by programs
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
library that record the window dimensions such as the
Most of the work is done by the inner function resize_term
. The outer
adds bookkeeping for the SIGWINCH
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.
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
Except as noted, these functions return the integer ERR
upon failure and
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
While these functions are intended to be used to support a signal handler (i.e.,
), care should be taken to avoid invoking them in a context
may have been interrupted, since it uses
If ncurses is configured to supply its own SIGWINCH
- on receipt of a SIGWINCH, the handler sets a
- which is tested in wgetch(3X) and
- 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
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
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).
Thomas Dickey (from an equivalent function written in 1988 for BSD