get_wch, wget_wch, mvget_wch, mvwget_wch, unget_wch - get
(or push back) a wide character from curses terminal key-
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);
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 char-
acter 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.
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
All functions except wget_wch and unget_wch may be macros.
When get_wch, wget_wch, mvget_wch, and mvwget_wch func-
tions 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
Upon successful completion, unget_wch returns OK. Other-
wise, the function returns ERR.
Functions with a "mv" prefix first perform a cursor move-
ment using wmove, and return an error if the position is
outside the window, or if the window pointer is null.
curses(3x), curs_getch(3x), curs_ins_wch(3x),
curs_inopts(3x), curs_move(3x), curs_refresh(3x)