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- * @Id: curs_getch.3x,v 1.74 2023/09/30 21:38:11 tom Exp @
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-<H1 class="no-header">curs_getch 3x 2023-09-30 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_getch 3x 2024-02-17 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>
<STRONG>int</STRONG> <STRONG>getch(void);</STRONG>
<STRONG>int</STRONG> <STRONG>wgetch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>);</STRONG>
-
<STRONG>int</STRONG> <STRONG>mvgetch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>);</STRONG>
<STRONG>int</STRONG> <STRONG>mvwgetch(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>int</STRONG> <STRONG>ungetch(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
- /* extension */
+ <EM>/*</EM> <EM>extension</EM> <EM>*/</EM>
<STRONG>int</STRONG> <STRONG>has_key(int</STRONG> <EM>ch</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>
+</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:
experience a delay between the time a user presses the escape key and
the escape is returned to the program.
- In <STRONG>ncurses</STRONG>, the timer normally expires after the value in <STRONG>ESCDELAY</STRONG> (see
+ In <EM>ncurses</EM>, the timer normally expires after the value in <STRONG>ESCDELAY</STRONG> (see
<STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>). If <STRONG>notimeout</STRONG> is <STRONG>TRUE</STRONG>, the timer does not expire;
it is an infinite (or very large) value. Because function keys usually
begin with an escape character, the terminal may appear to hang in
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
KEY_ENTER Enter or send
KEY_SRESET Soft (partial) reset
KEY_RESET Reset or hard reset
-
KEY_PRINT Print or copy
+
KEY_LL Home down or bottom (lower left)
KEY_A1 Upper left of keypad
KEY_A3 Upper right of keypad
<STRONG>o</STRONG> <STRONG>KEY_MOUSE</STRONG> is returned for mouse-events (see <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>). This
code relies upon whether or not <STRONG><A HREF="curs_inopts.3x.html">keypad(3x)</A></STRONG> has been enabled,
- because (e.g., with <STRONG>xterm(1)</STRONG> mouse prototocol) ncurses must read
+ because (e.g., with <STRONG>xterm(1)</STRONG> mouse prototocol) <EM>ncurses</EM> must read
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.
returns <STRONG>ERR</STRONG> if there is no more room in the FIFO.
<STRONG>wgetch</STRONG>
- returns <STRONG>ERR</STRONG> if the window pointer is null, or if its timeout
- expires without having any data, or if the execution was
- interrupted by a signal (<STRONG>errno</STRONG> will be set to <STRONG>EINTR</STRONG>).
+ returns <STRONG>ERR</STRONG>
+
+ <STRONG>o</STRONG> if the window pointer is null, or
+
+ <STRONG>o</STRONG> if its timeout expires without having any data, or
- Functions with a "mv" prefix first perform a cursor movement using
+ <STRONG>o</STRONG> if the execution was interrupted by a signal (<STRONG>errno</STRONG> will be
+ set to <STRONG>EINTR</STRONG>).
+
+ Functions with a "mv" prefix first perform a cursor movement using
<STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
the window pointer is null.
</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
- Use of the escape key by a programmer for a single character function
- is discouraged, as it will cause a delay of up to one second while the
+ Use of the escape key by a programmer for a single character function
+ is discouraged, as it will cause a delay of up to one second while the
keypad code looks for a following function-key sequence.
- Some keys may be the same as commonly used control keys, e.g.,
+ Some keys may be the same as commonly used control keys, e.g.,
<STRONG>KEY_ENTER</STRONG> versus control/M, <STRONG>KEY_BACKSPACE</STRONG> versus control/H. Some
curses implementations may differ according to whether they treat these
- control keys specially (and ignore the terminfo), or use the terminfo
- definitions. <STRONG>Ncurses</STRONG> uses the terminfo definition. If it says that
- <STRONG>KEY_ENTER</STRONG> is control/M, <STRONG>getch</STRONG> will return <STRONG>KEY_ENTER</STRONG> when you press
+ control keys specially (and ignore the terminfo), or use the terminfo
+ definitions. <EM>ncurses</EM> uses the terminfo definition. If it says that
+ <STRONG>KEY_ENTER</STRONG> is control/M, <STRONG>getch</STRONG> will return <STRONG>KEY_ENTER</STRONG> when you press
control/M.
- Generally, <STRONG>KEY_ENTER</STRONG> denotes the character(s) sent by the <EM>Enter</EM> key on
+ Generally, <STRONG>KEY_ENTER</STRONG> denotes the character(s) sent by the <EM>Enter</EM> key on
the numeric keypad:
<STRONG>o</STRONG> the terminal description lists the most useful keys,
- <STRONG>o</STRONG> the <EM>Enter</EM> key on the regular keyboard is already handled by the
+ <STRONG>o</STRONG> the <EM>Enter</EM> key on the regular keyboard is already handled by the
standard ASCII characters for carriage-return and line-feed,
<STRONG>o</STRONG> depending on whether <STRONG>nl</STRONG> or <STRONG>nonl</STRONG> was called, pressing "Enter" on the
- regular keyboard may return either a carriage-return or line-feed,
+ regular keyboard may return either a carriage-return or line-feed,
and finally
<STRONG>o</STRONG> "Enter or send" is the standard description for this key.
- When using <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, or <STRONG>mvwgetch</STRONG>, nocbreak mode
- (<STRONG>nocbreak</STRONG>) and echo mode (<STRONG>echo</STRONG>) should not be used at the same time.
- Depending on the state of the tty driver when each character is typed,
+ When using <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, or <STRONG>mvwgetch</STRONG>, nocbreak mode
+ (<STRONG>nocbreak</STRONG>) and echo mode (<STRONG>echo</STRONG>) should not be used at the same time.
+ Depending on the state of the tty driver when each character is typed,
the program may produce undesirable results.
Note that <STRONG>getch</STRONG>, <STRONG>mvgetch</STRONG>, and <STRONG>mvwgetch</STRONG> may be macros.
- Historically, the set of keypad macros was largely defined by the
- extremely function-key-rich keyboard of the AT&T 7300, aka 3B1, aka
- Safari 4. Modern personal computers usually have only a small subset
- of these. IBM PC-style consoles typically support little more than
- <STRONG>KEY_UP</STRONG>, <STRONG>KEY_DOWN</STRONG>, <STRONG>KEY_LEFT</STRONG>, <STRONG>KEY_RIGHT</STRONG>, <STRONG>KEY_HOME</STRONG>, <STRONG>KEY_END</STRONG>, <STRONG>KEY_NPAGE</STRONG>,
- <STRONG>KEY_PPAGE</STRONG>, and function keys 1 through 12. The Ins key is usually
+ Historically, the set of keypad macros was largely defined by the
+ extremely function-key-rich keyboard of the AT&T 7300, aka 3B1, aka
+ Safari 4. Modern personal computers usually have only a small subset
+ of these. IBM PC-style consoles typically support little more than
+ <STRONG>KEY_UP</STRONG>, <STRONG>KEY_DOWN</STRONG>, <STRONG>KEY_LEFT</STRONG>, <STRONG>KEY_RIGHT</STRONG>, <STRONG>KEY_HOME</STRONG>, <STRONG>KEY_END</STRONG>, <STRONG>KEY_NPAGE</STRONG>,
+ <STRONG>KEY_PPAGE</STRONG>, and function keys 1 through 12. The Ins key is usually
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.
+ 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 adopted from the XSI Curses standard.
+ description is adapted from X/Open Curses.
- 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.
+ 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 XSI Curses, along with a few related terminfo
- capabilities, but no higher-level functions use the feature. The
- implementation in ncurses is an extension.
+ <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 ncurses. 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
<STRONG>EINTR</STRONG>.
- The <STRONG>has_key</STRONG> function is unique to <STRONG>ncurses</STRONG>. 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.
-ncurses 6.4 202
3-09-30 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
+ncurses 6.4 202
4-02-17 <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>
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