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<H1 class="no-header">curs_get_wch 3x 2025-08-16 ncurses 6.6 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
<STRONG>get_wch</STRONG>, <STRONG>wget_wch</STRONG>, <STRONG>mvget_wch</STRONG>, <STRONG>mvwget_wch</STRONG>, <STRONG>unget_wch</STRONG> - get (or push
back) a wide character from <EM>curses</EM> terminal keyboard buffer
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>int</STRONG> <STRONG>get_wch(wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>wget_wch(WINDOW</STRONG> <STRONG>*</STRONG> <EM>win</EM><STRONG>,</STRONG> <STRONG>wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>mvget_wch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>mvwget_wch(WINDOW</STRONG> <STRONG>*</STRONG> <EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>,</STRONG> <STRONG>wint_t</STRONG> <STRONG>*</STRONG> <EM>wch</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>unget_wch(const</STRONG> <STRONG>wchar_t</STRONG> <EM>wc</EM><STRONG>);</STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
</PRE><H3><a name="h3-Reading-Characters">Reading Characters</a></H3><PRE>
<STRONG>wget_wch</STRONG> gathers a key event from the terminal keyboard associated with
a <EM>curses</EM> window <EM>win</EM>, returning <STRONG>OK</STRONG> if a wide character is read,
<STRONG>KEY_CODE_YES</STRONG> if a function key is read, and <STRONG>ERR</STRONG> if no key event is
available. <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG> describes the variants of this function.
When input is pending, <STRONG>wget_wch</STRONG> stores an integer identifying the key
event in <EM>wch</EM>; for alphanumeric and punctuation keys, this value
corresponds to the character encoding used by the terminal. Use of the
control key as a modifier, by holding it down while pressing and
releasing another key, often results in a distinct code. The behavior
of other keys depends on whether <EM>win</EM> is in keypad mode; see subsections
"Keypad Mode" and "Key Codes" in <STRONG><A HREF="curs_getch.3x.html">getch(3x)</A></STRONG>.
If no input is pending, then if the no-delay flag is set in the window
(see <STRONG><A HREF="nodelay.3x.html">nodelay(3x)</A></STRONG>), the function returns <STRONG>ERR</STRONG>; otherwise, <EM>curses</EM> waits
until the terminal has input. If <STRONG><A HREF="curs_inopts.3x.html">cbreak(3x)</A></STRONG> or <STRONG><A HREF="curs_inopts.3x.html">raw(3x)</A></STRONG> has been
called, this happens after one character is read. If <STRONG><A HREF="curs_inopts.3x.html">nocbreak(3x)</A></STRONG> or
<STRONG><A HREF="curs_inopts.3x.html">noraw(3x)</A></STRONG> has been called, it occurs when the next newline is read.
(Because the terminal's canonical or "cooked" mode is line-buffered,
multiple <STRONG>wget_wch</STRONG> calls may then be necessary to empty the input
queue.) If <STRONG><A HREF="curs_inopts.3x.html">halfdelay(3x)</A></STRONG> has been called, <EM>curses</EM> waits until input is
available or the specified delay elapses.
If <STRONG><A HREF="curs_inopts.3x.html">echo(3x)</A></STRONG> has been called, and the window is not a pad, <EM>curses</EM> writes
the wide character from the input queue to the window (at the cursor
position) per the following rules.
<STRONG>o</STRONG> If the wide character matches the terminal's erase character (see
<STRONG><A HREF="curs_termattrs.3x.html">erasewchar(3x)</A></STRONG>), the cursor moves leftward one position and the new
position is erased as if <STRONG><A HREF="curs_move.3x.html">wmove(3x)</A></STRONG> and then <STRONG><A HREF="curs_delch.3x.html">wdelch(3x)</A></STRONG> were called.
When the window's keypad mode is enabled (see below), <STRONG>KEY_LEFT</STRONG> and
<STRONG>KEY_BACKSPACE</STRONG> are handled the same way.
<STRONG>o</STRONG> <EM>curses</EM> writes any other wide character to the window, as with
<STRONG><A HREF="curs_add_wch.3x.html">wecho_wchar(3x)</A></STRONG>.
<STRONG>o</STRONG> If the window <EM>win</EM> has been moved or modified since the last call to
<STRONG><A HREF="curs_refresh.3x.html">wrefresh(3x)</A></STRONG>, <EM>curses</EM> calls <STRONG>wrefresh</STRONG> on it.
If the wide character is a carriage return and <STRONG><A HREF="curs_inopts.3x.html">nl(3x)</A></STRONG> has been called,
<STRONG>wget_wch</STRONG> stores the wide character code for line feed in <EM>wch</EM> instead.
</PRE><H3><a name="h3-Ungetting-Characters">Ungetting Characters</a></H3><PRE>
<STRONG>unget_wch</STRONG> places <EM>wc</EM> into the input queue to be retrieved by the next
call to <STRONG>wget_wch</STRONG>. A single input queue serves all windows associated
with the screen.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
<STRONG>wget_wch</STRONG> returns <STRONG>OK</STRONG> when it reads a wide character, <STRONG>KEY_CODE_YES</STRONG> when
it reads a function key code, and <STRONG>ERR</STRONG> on failure. <STRONG>wget_wch</STRONG> fails if
its timeout expires without any data arriving, which cannot happen if
<STRONG><A HREF="nodelay.3x.html">nodelay(3x)</A></STRONG> is in effect on the window.
In <EM>ncurses</EM>, <STRONG>wget_wch</STRONG> also fails if
<STRONG>o</STRONG> the <EM>curses</EM> screen has not been initialized,
<STRONG>o</STRONG> (for functions taking a <EM>WINDOW</EM> pointer argument) <EM>win</EM> is a null
pointer, or
<STRONG>o</STRONG> execution was interrupted by a signal, in which case <EM>errno</EM> is set
to <EM>EINTR</EM>.
Functions prefixed with "mv" first perform cursor movement and fail if
the position (<EM>y</EM>, <EM>x</EM>) is outside the window boundaries.
<STRONG>unget_wch</STRONG> returns <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on failure. In <EM>ncurses</EM>,
<STRONG>unget_wch</STRONG> fails if
<STRONG>o</STRONG> the <EM>curses</EM> screen has not been initialized, or
<STRONG>o</STRONG> there is no more room in the input queue.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
See the "NOTES" section of <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>.
All of these functions except <STRONG>wget_wch</STRONG> and <STRONG>unget_wch</STRONG> may be implemented
as macros.
Unlike <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>, <STRONG>wget_wch</STRONG> stores the value of the input character in
an additional <EM>wch</EM> parameter instead of the return value.
Unlike <STRONG>ungetch</STRONG>, <STRONG>unget_wch</STRONG> cannot distinguish function key codes from
conventional character codes. An application can overcome this
limitation by pushing function key codes with <STRONG>ungetch</STRONG> and subsequently
checking the return value of <STRONG>wget_wch</STRONG> for a match with <STRONG>KEY_CODE_YES</STRONG>.
</PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE>
See the "EXTENSIONS" section of <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>.
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
Applications employing <EM>ncurses</EM> extensions should condition their use on
the visibility of the <STRONG>NCURSES_VERSION</STRONG> preprocessor macro.
X/Open Curses Issue 4 describes these functions. It specifies no error
conditions for them.
See the "PORTABILITY" section of <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> regarding the interaction
of <EM>wget</EM><STRONG>_</STRONG><EM>wch</EM> with signal handlers.
</PRE><H2><a name="h2-HISTORY">HISTORY</a></H2><PRE>
X/Open Curses Issue 4 (1995) initially specified these functions. The
System V Interface Definition Version 4 of the same year specified
functions named <EM>wgetwch</EM> (with its variants) <EM>ungetwch</EM>. These were later
additions to SVr4.<EM>x</EM>, not appearing in the first SVr4 (1989). They
differ from X/Open's later <EM>wget</EM><STRONG>_</STRONG><EM>wch</EM> and <EM>unget</EM><STRONG>_</STRONG><EM>wch</EM> in that <EM>wgetwch</EM> takes
no <EM>wch</EM> argument, but returns the (wide) key code as an <EM>int</EM> (with no
provision for distinguishing a character code from a function key
code); and <EM>ungetwch</EM> takes a non-<EM>const</EM> <EM>int</EM> argument.
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
<STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> describes comparable functions of the <EM>ncurses</EM> library in
its non-wide-character configuration.
<STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG>, <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>, <STRONG><A HREF="curs_move.3x.html">curs_move(3x)</A></STRONG>,
<STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>
ncurses 6.6 2025-08-16 <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
<ul>
<li><a href="#h3-Reading-Characters">Reading Characters</a></li>
<li><a href="#h3-Ungetting-Characters">Ungetting Characters</a></li>
</ul>
</li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-NOTES">NOTES</a></li>
<li><a href="#h2-EXTENSIONS">EXTENSIONS</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
<li><a href="#h2-HISTORY">HISTORY</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
</ul>
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