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30 * @Id: curs_get_wch.3x,v 1.15 2021/05/22 22:33:19 tom Exp @
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42 <H1 class="no-header">curs_get_wch 3X</H1>
44 <B><A HREF="curs_get_wch.3X.html">curs_get_wch(3X)</A></B> <B><A HREF="curs_get_wch.3X.html">curs_get_wch(3X)</A></B>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <B>get_wch</B>, <B>wget_wch</B>, <B>mvget_wch</B>, <B>mvwget_wch</B>, <B>unget_wch</B> - get (or push
51 back) a wide character from curses terminal keyboard
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <B>#include</B> <B><curses.h></B>
57 <B>int</B> <B>get_wch(wint_t</B> <B>*</B><I>wch</I><B>);</B>
58 <B>int</B> <B>wget_wch(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>wint_t</B> <B>*</B><I>wch</I><B>);</B>
59 <B>int</B> <B>mvget_wch(int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>wint_t</B> <B>*</B><I>wch</I><B>);</B>
60 <B>int</B> <B>mvwget_wch(WINDOW</B> <B>*</B><I>win</I><B>,</B> <B>int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>,</B> <B>wint_t</B> <B>*</B><I>wch</I><B>);</B>
62 <B>int</B> <B>unget_wch(const</B> <B>wchar_t</B> <I>wch</I><B>);</B>
65 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
67 </PRE><H3><a name="h3-wget_wch">wget_wch</a></H3><PRE>
68 The <B>get_wch</B>, <B>wget_wch</B>, <B>mvget_wch</B>, and <B>mvwget_wch</B> functions read a char-
69 acter from the terminal associated with the current or specified win-
70 dow. In no-delay mode, if no input is waiting, the value <B>ERR</B> is re-
71 turned. In delay mode, the program waits until the system passes text
72 through to the program. Depending on the setting of <B>cbreak</B>, this is
73 after one character (cbreak mode), or after the first newline (nocbreak
74 mode). In half-delay mode, the program waits until the user types a
75 character or the specified timeout interval has elapsed.
77 Unless <B>noecho</B> has been set, these routines echo the character into the
80 If the window is not a pad and has been moved or modified since the
81 last call to <B>wrefresh</B>, <B>wrefresh</B> will be called before another character
84 If <B>keypad</B> is enabled, these functions respond to the pressing of a
85 function key by setting the object pointed to by <I>wch</I> to the keycode as-
86 signed to the function key, and returning <B>KEY_CODE_YES</B>. If a character
87 (such as escape) that could be the beginning of a function key is re-
88 ceived, curses sets a timer. If the remainder of the sequence does ar-
89 rive within the designated time, curses passes through the character;
90 otherwise, curses returns the function key value. For this reason,
91 many terminals experience a delay between the time a user presses the
92 escape key and the time the escape is returned to the program.
94 The keycodes returned by these functions are the same as those returned
97 <B>o</B> The predefined function keys are listed in <B><curses.h></B> as macros
98 with values outside the range of 8-bit characters. Their names be-
101 <B>o</B> Other (user-defined) function keys which may be defined using <B>de-</B>
102 <B><A HREF="define_key.3X.html">fine_key(3X)</A></B> have no names, but also are expected to have values
103 outside the range of 8-bit characters.
106 </PRE><H3><a name="h3-unget_wch">unget_wch</a></H3><PRE>
107 The <B>unget_wch</B> function pushes the wide character <I>wch</I> back onto the head
108 of the input queue, so the wide character is returned by the next call
109 to <B>get_wch</B>. The pushback of one character is guaranteed. If the pro-
110 gram calls <B>unget_wch</B> too many times without an intervening call to
111 <B>get_wch</B>, the operation may fail.
113 Unlike <B>ungetch</B> and <B>wgetch</B>, <B>unget_wch</B> cannot distinguish special charac-
114 ters returned by <B>wget_wch</B> from ordinary characters. An application can
115 push special keys which it may read via <B>wget_wch</B> by checking for the
116 <B>KEY_CODE_YES</B> result, and using <B>ungetch</B> for those special keys.
119 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
120 The header file <B><curses.h></B> automatically includes the header file
121 <B><stdio.h></B>.
123 Applications should not define the escape key by itself as a single-
126 When using <B>get_wch</B>, <B>wget_wch</B>, <B>mvget_wch</B>, or <B>mvwget_wch</B>, applications
127 should not use <B>nocbreak</B> mode and <B>echo</B> mode at the same time. Depending
128 on the state of the tty driver when each character is typed, the pro-
129 gram may produce undesirable results.
131 All functions except <B>wget_wch</B> and <B>unget_wch</B> may be macros.
134 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
135 When <B>get_wch</B>, <B>wget_wch</B>, <B>mvget_wch</B>, and <B>mvwget_wch</B> functions successful-
136 ly report the pressing of a function key, they return <B>KEY_CODE_YES</B>.
137 When they successfully report a wide character, they return <B>OK</B>. Other-
138 wise, they return <B>ERR</B>.
140 Upon successful completion, <B>unget_wch</B> returns <B>OK</B>. Otherwise, the func-
141 tion returns <B>ERR</B>.
143 Functions with a "mv" prefix first perform a cursor movement using
144 <B>wmove</B>, and return an error if the position is outside the window, or if
145 the window pointer is null.
148 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
149 <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="curs_getch.3X.html">curs_getch(3X)</A></B>, <B><A HREF="curs_ins_wch.3X.html">curs_ins_wch(3X)</A></B>, <B><A HREF="curs_inopts.3X.html">curs_inopts(3X)</A></B>,
150 <B><A HREF="curs_move.3X.html">curs_move(3X)</A></B>, <B><A HREF="curs_refresh.3X.html">curs_refresh(3X)</A></B>
154 <B><A HREF="curs_get_wch.3X.html">curs_get_wch(3X)</A></B>
158 <li><a href="#h2-NAME">NAME</a></li>
159 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
160 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
162 <li><a href="#h3-wget_wch">wget_wch</a></li>
163 <li><a href="#h3-unget_wch">unget_wch</a></li>
166 <li><a href="#h2-NOTES">NOTES</a></li>
167 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
168 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>