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<H1 class="no-header">curs_get_wch 3x 2024-04-20 ncurses 6.5 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
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
<STRONG>#include</STRONG> <STRONG>&lt;curses.h&gt;</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 stroke <EM>wch</EM> 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
stroke 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 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 "Predefined 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> has been called, this
happens after one character is read. If <STRONG><A HREF="curs_inopts.3x.html">nocbreak(3x)</A></STRONG> has been called,
it occurs when the next newline is read. If <STRONG><A HREF="curs_inopts.3x.html">halfdelay(3x)</A></STRONG> has been
called, <EM>curses</EM> waits until a character is typed 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
<EM>wch</EM> to the window (at the cursor position) per the following rules.
<STRONG>o</STRONG> If <EM>wch</EM> matches the terminal's erase character, 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 <EM>wch</EM> to the window, as with <STRONG><A HREF="curs_add_wch.3x.html">wecho_wchar(3x)</A></STRONG>.
<STRONG>o</STRONG> If the window 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>.
If <EM>wch</EM> is a carriage return and <STRONG><A HREF="curs_inopts.3x.html">nl(3x)</A></STRONG> has been called, <STRONG>wgetch</STRONG> stores
the the character code for newline (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>wch</EM> into the input queue to be returned by the next
call to <STRONG>wget_wch</STRONG>. A single input queue serves all windows.
</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 and <STRONG>KEY_CODE_YES</STRONG>
when it reads a function key code. It returns <STRONG>ERR</STRONG> if
<STRONG>o</STRONG> the <EM>WINDOW</EM> pointer is <STRONG>NULL</STRONG>, or
<STRONG>o</STRONG> its timeout expires without any data arriving, or
<STRONG>o</STRONG> execution was interrupted by a signal, in which case <STRONG>errno</STRONG> is set
to <STRONG>EINTR</STRONG>.
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> if 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> and its variants store 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
<STRONG>wget_wch</STRONG> 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 <STRONG>wget_wch</STRONG> with signal handlers.
</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 6.5 2024-04-20 <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-SEE-ALSO">SEE ALSO</a></li>
</ul>
</div>
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