изменить размер терминала проклятия (change the curses terminal size)
Имя (Name)
is_term_resized
, resize_term
, resizeterm
- change the curses
terminal size
Синопсис (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);
Описание (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.
Возвращаемое значение (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.
Примечание (Note)
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.
Портативность (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).
Смотри также (See also)
curs_getch
(3X), curs_variables
(3X), wresize
(3X).