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30 .\" $Id: curs_get_wch.3x,v 1.40 2024/04/20 19:23:03 tom Exp $
31 .TH curs_get_wch 3X 2024-04-20 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"
53 get (or push back) a wide character from \fIcurses\fR terminal keyboard
56 \fB#include <curses.h>
58 \fBint get_wch(wint_t *\fIwch\fP);
59 \fBint wget_wch(WINDOW *\fIwin\fP, wint_t *\fIwch\fP);
60 \fBint mvget_wch(int \fIy\fP, int \fIx\fP, wint_t *\fIwch\fP);
61 \fBint mvwget_wch(WINDOW *\fIwin\fP, int \fIy\fP, int \fIx\fP, wint_t *\fIwch\fP);
63 \fBint unget_wch(const wchar_t \fIwc\fP);
66 .SS "Reading Characters"
70 from the terminal keyboard associated with a
76 if a wide character is read,
78 if a function key is read,
81 if no key event is available.
82 \fB\%ncurses\fP(3X) describes the variants of this function.
84 When input is pending,
87 identifying the key stroke in
89 for alphanumeric and punctuation keys,
90 this value corresponds to the character encoding used by the terminal.
91 Use of the control key as a modifier often results in a distinct code.
92 The behavior of other keys depends on whether
95 see subsections \*(``Keypad Mode\*('' and \*(``Predefined Key Codes\*(''
98 If no input is pending,
99 then if the no-delay flag is set in the window
100 (see \fB\%nodelay\fP(3X)),
105 waits until the terminal has input.
106 If \fB\%cbreak\fP(3X)
108 this happens after one character is read.
109 If \fB\%nocbreak\fP(3X)
111 it occurs when the next newline is read.
112 If \fB\%halfdelay\fP(3X)
115 waits until a character is typed or the specified delay elapses.
117 If \fB\%echo\fP(3X) has been called,
118 and the window is not a pad,
123 (at the cursor position)
124 per the following rules.
128 matches the terminal's erase character,
129 the cursor moves leftward one position
130 and the new position is erased
131 as if \fB\%wmove\fP(3X) and then \fB\%wdelch\fP(3X) were called.
132 When the window's keypad mode is enabled
137 are handled the same way.
143 as with \fB\%wecho_wchar\fP(3X).
145 If the window has been moved or modified since the last call to
146 \fB\%wrefresh\fP(3X),
153 is a carriage return and \fBnl\fP(3X) has been called,
155 stores the the character code for newline
160 .SS "Ungetting Characters"
164 into the input queue to be returned by the next call to
166 A single input queue serves all windows.
171 when it reads a wide character and
173 when it reads a function key code.
184 its timeout expires without any data arriving,
187 execution was interrupted by a signal,
193 Functions prefixed with \*(``mv\*('' first perform cursor movement and
197 is outside the window boundaries.
204 if there is no more room in the input queue.
206 See the \*(``NOTES\*('' section of \fB\%wgetch\fP(3X).
208 All of these functions except
212 may be implemented as macros.
214 Unlike \fB\%wgetch\fP(3X),
216 and its variants store the value of the input character in an additional
218 parameter instead of the return value.
223 cannot distinguish function key codes
225 from conventional character codes.
226 An application can overcome this limitation by pushing function key
229 and subsequently checking the return value of
234 See the \*(``EXTENSIONS\*('' section of \fB\%wgetch\fP(3X).
236 Applications employing
238 extensions should condition their use on the visibility of the
243 Issue 4 describes these functions.
244 It specifies no error conditions for them.
246 See the \*(``PORTABILITY\*('' section of \fB\%wgetch\fP(3X) regarding
249 with signal handlers.
251 \fB\%curs_getch\fP(3X) describes comparable functions of the
253 library in its non-wide-character configuration.
256 \fB\%curs_add_wch\fP(3X),
257 \fB\%curs_inopts\fP(3X),
258 \fB\%curs_move\fP(3X),
259 \fB\%curs_refresh\fP(3X)