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- * @Id: curs_getch.3x,v 1.76 2023/12/16 21:01:28 tom Exp @
+ * @Id: curs_getch.3x,v 1.77 2023/12/23 16:36:18 tom Exp @
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+<TITLE>curs_getch 3x 2023-12-23 ncurses 6.4 Library calls</TITLE>
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-<H1 class="no-header">curs_getch 3x 2023-12-16 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_getch 3x 2023-12-23 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
-</PRE><H3><a name="h3-Reading-characters">Reading characters</a></H3><PRE>
+</PRE><H3><a name="h3-Reading-Characters">Reading Characters</a></H3><PRE>
The <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG> and <STRONG>mvwgetch</STRONG>, routines read a character from
the window. In no-delay mode, if no input is waiting, the value <STRONG>ERR</STRONG> is
returned. In delay mode, the program waits until the system passes
is read.
-</PRE><H3><a name="h3-Keypad-mode">Keypad mode</a></H3><PRE>
+</PRE><H3><a name="h3-Keypad-Mode">Keypad Mode</a></H3><PRE>
If <STRONG>keypad</STRONG> is <STRONG>TRUE</STRONG>, and a function key is pressed, the token for that
function key is returned instead of the raw characters:
pressed.
-</PRE><H3><a name="h3-Ungetting-characters">Ungetting characters</a></H3><PRE>
+</PRE><H3><a name="h3-Ungetting-Characters">Ungetting Characters</a></H3><PRE>
The <STRONG>ungetch</STRONG> routine places <EM>ch</EM> back onto the input queue to be returned
by the next call to <STRONG>wgetch</STRONG>. There is just one input queue for all
windows.
-</PRE><H3><a name="h3-Predefined-key-codes">Predefined key-codes</a></H3><PRE>
+</PRE><H3><a name="h3-Predefined-Key-Codes">Predefined Key Codes</a></H3><PRE>
The following special keys are defined in <STRONG><curses.h></STRONG>.
<STRONG>o</STRONG> Except for the special case <STRONG>KEY_RESIZE</STRONG>, it is necessary to enable
escape sequences, just like a function key.
-</PRE><H3><a name="h3-Testing-key-codes">Testing key-codes</a></H3><PRE>
+</PRE><H3><a name="h3-Testing-Key-Codes">Testing Key Codes</a></H3><PRE>
The <STRONG>has_key</STRONG> routine takes a key-code value from the above list, and
returns <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG> according to whether the current terminal type
recognizes a key with that value.
mapped to <STRONG>KEY_IC</STRONG>.
+</PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE>
+ <STRONG>has_key</STRONG> was designed for <STRONG><A HREF="ncurses.3x.html">ncurses(3x)</A></STRONG>, and is not found in SVr4 <EM>curses</EM>,
+ 4.4BSD <EM>curses</EM>, or any other previous curses implementation.
+
+
</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
- The *get* functions are described in the XSI Curses standard, Issue 4.
- They read single-byte characters only. The standard specifies that
- they return <STRONG>ERR</STRONG> on failure, but specifies no error conditions.
-
- The echo behavior of these functions on input of <STRONG>KEY_</STRONG> or backspace
- characters was not specified in the SVr4 documentation. This
- description is adopted from the XSI Curses standard.
-
- The behavior of <STRONG>getch</STRONG> and friends in the presence of handled signals is
- unspecified in the SVr4 and XSI Curses documentation. Under historical
- curses implementations, it varied depending on whether the operating
- system's implementation of handled signal receipt interrupts a <STRONG>read(2)</STRONG>
- call in progress or not, and also (in some implementations) depending
- on whether an input timeout or non-blocking mode has been set.
-
- <STRONG>KEY_MOUSE</STRONG> is mentioned in XSI Curses, along with a few related terminfo
- capabilities, but no higher-level functions use the feature. The
+ 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, Version 2, describes <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>,
+ <STRONG>mvwgetch</STRONG>, and <STRONG>ungetch</STRONG>. They read single-byte characters only. The
+ standard specifies that they return <STRONG>ERR</STRONG> on failure, but describes no
+ failure conditions.
+
+ The echo behavior of these functions on input of <STRONG>KEY_</STRONG> or backspace
+ characters was not specified in the SVr4 documentation. This
+ description is adapted from X/Open Curses.
+
+ The behavior of <STRONG>getch</STRONG> and friends in the presence of signal handlers is
+ unspecified in the SVr4 documentation and X/Open Curses. Under
+ historical curses implementations, it varied depending on whether the
+ operating system's dispatch of a signal to a handler interrupts a
+ <STRONG>read(2)</STRONG> call in progress or not, and also (in some implementations)
+ whether an input timeout or non-blocking mode has been set.
+
+ <STRONG>KEY_MOUSE</STRONG> is mentioned in X/Open Curses, along with a few related <EM>term-</EM>
+ <EM>info</EM> capabilities, but no higher-level functions use the feature. The
implementation in <EM>ncurses</EM> is an extension.
- <STRONG>KEY_RESIZE</STRONG> is an extension first implemented for <EM>ncurses</EM>. NetBSD
- curses later added this extension.
+ <STRONG>KEY_RESIZE</STRONG> is an extension first implemented for <EM>ncurses.</EM> NetBSD
+ <EM>curses</EM> later added this extension.
- Programmers concerned about portability should be prepared for either
- of two cases: (a) signal receipt does not interrupt <STRONG>getch</STRONG>; (b) signal
- receipt interrupts <STRONG>getch</STRONG> and causes it to return <STRONG>ERR</STRONG> with <STRONG>errno</STRONG> set to
+ Programmers concerned about portability should be prepared for either
+ of two cases: (a) signal receipt does not interrupt <STRONG>getch</STRONG>; (b) signal
+ receipt interrupts <STRONG>getch</STRONG> and causes it to return <STRONG>ERR</STRONG> with <STRONG>errno</STRONG> set to
<STRONG>EINTR</STRONG>.
- The <STRONG>has_key</STRONG> function is unique to <EM>ncurses</EM>. We recommend that any code
+ The <STRONG>has_key</STRONG> function is unique to <EM>ncurses</EM>. We recommend that any code
using it be conditionalized on the <STRONG>NCURSES_VERSION</STRONG> feature macro.
<STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>, <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>, <STRONG><A HREF="curs_move.3x.html">curs_move(3x)</A></STRONG>,
<STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG>
- Comparable functions in the wide-character (ncursesw) library are
+ Comparable functions in the wide-character (ncursesw) library are
described in <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>.
-ncurses 6.4 2023-12-16 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
+ncurses 6.4 2023-12-23 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<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-Keypad-mode">Keypad mode</a></li>
-<li><a href="#h3-Ungetting-characters">Ungetting characters</a></li>
-<li><a href="#h3-Predefined-key-codes">Predefined key-codes</a></li>
-<li><a href="#h3-Testing-key-codes">Testing key-codes</a></li>
+<li><a href="#h3-Reading-Characters">Reading Characters</a></li>
+<li><a href="#h3-Keypad-Mode">Keypad Mode</a></li>
+<li><a href="#h3-Ungetting-Characters">Ungetting Characters</a></li>
+<li><a href="#h3-Predefined-Key-Codes">Predefined Key Codes</a></li>
+<li><a href="#h3-Testing-Key-Codes">Testing Key Codes</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>