NAME¶
get_wch,
wget_wch,
mvget_wch,
mvwget_wch,
unget_wch - get (or push back) a wide character from curses terminal
keyboard
SYNOPSIS¶
#include <curses.h>
int get_wch(wint_t *wch);
int wget_wch(WINDOW *win, wint_t *wch);
int mvget_wch(int y, int x, wint_t
*wch );
int mvwget_wch(WINDOW *win, int y, int
x , wint_t *wch);
int unget_wch(const wchar_t wch);
DESCRIPTION¶
The
get_wch,
wget_wch,
mvget_wch, and
mvwget_wch
functions read a character from the terminal associated with the current or
specified window. In no-delay mode, if no input is waiting, the value
ERR is returned. In delay mode, the program waits until the system
passes text through to the program. Depending on the setting of
cbreak,
this is after one character (cbreak mode), or after the first newline
(nocbreak mode). In half-delay mode, the program waits until the user types a
character or the specified timeout interval has elapsed.
Unless
noecho has been set, these routines echo the character into the
designated window.
If the window is not a pad and has been moved or modified since the last call to
wrefresh,
wrefresh will be called before another character is
read.
If
keypad is enabled, these functions respond to the pressing of a
function key by setting the object pointed to by
wch to the
corresponding
KEY_ value defined in
<curses.h> and
returning
KEY_CODE_YES. If a character (such as escape) that could be
the beginning of a function key is received, curses sets a timer. If the
remainder of the sequence does arrive within the designated time, curses
passes through the character; otherwise, curses returns the function key
value. For this reason, many terminals experience a delay between the time a
user presses the escape key and the time the escape is returned to the
program.
The
unget_wch function pushes the wide character
wch back onto the
head of the input queue, so the wide character is returned by the next call to
get_wch. The pushback of one character is guaranteed. If the program
calls
unget_wch too many times without an intervening call to
get_wch, the operation may fail.
NOTES¶
The header file
<curses.h> automatically includes the header file
<stdio.h>.
Applications should not define the escape key by itself as a single-character
function.
When using
get_wch,
wget_wch,
mvget_wch, or
mvwget_wch, applications should not use
nocbreak mode and
echo mode at the same time. Depending on the state of the tty driver
when each character is typed, the program may produce undesirable results.
All functions except
wget_wch and
unget_wch may be macros.
RETURN VALUE¶
When
get_wch,
wget_wch,
mvget_wch, and
mvwget_wch
functions successfully report the pressing of a function key, they return
KEY_CODE_YES. When they successfully report a wide character, they
return
OK. Otherwise, they return
ERR.
Upon successful completion,
unget_wch returns
OK. Otherwise, the
function returns
ERR.
Functions with a "mv" prefix first perform a cursor movement using
wmove, and return an error if the position is outside the window, or if
the window pointer is null.
SEE ALSO¶
ncurses(3NCURSES),
getch(3NCURSES),
ins_wch(3NCURSES),
inopts(3NCURSES),
move(3NCURSES),
refresh(3NCURSES)