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-<H1 class="no-header">curs_getch 3X</H1>
+<H1 class="no-header">curs_getch 3x</H1>
<PRE>
-<B><A HREF="curs_getch.3X.html">curs_getch(3X)</A></B> <B><A HREF="curs_getch.3X.html">curs_getch(3X)</A></B>
+<STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
- <B>getch</B>, <B>wgetch</B>, <B>mvgetch</B>, <B>mvwgetch</B>, <B>ungetch</B>, <B>has_key</B> - get (or push back)
- characters from <B>curses</B> terminal keyboard
+ <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, <STRONG>mvwgetch</STRONG>, <STRONG>ungetch</STRONG>, <STRONG>has_key</STRONG> - get (or push back)
+ characters from <STRONG>curses</STRONG> terminal keyboard
</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
- <B>#include</B> <B><curses.h></B>
+ <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
- <B>int</B> <B>getch(void);</B>
- <B>int</B> <B>wgetch(WINDOW</B> <B>*</B><I>win);</I>
+ <STRONG>int</STRONG> <STRONG>getch(void);</STRONG>
+ <STRONG>int</STRONG> <STRONG>wgetch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win);</EM>
- <B>int</B> <B>mvgetch(int</B> <I>y</I><B>,</B> <B>int</B> <I>x</I><B>);</B>
- <B>int</B> <B>mvwgetch(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>
+ <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>
- <B>int</B> <B>ungetch(int</B> <I>ch</I><B>);</B>
+ <STRONG>int</STRONG> <STRONG>ungetch(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
/* extension */
- <B>int</B> <B>has_key(int</B> <I>ch</I><B>);</B>
+ <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>
- The <B>getch</B>, <B>wgetch</B>, <B>mvgetch</B> and <B>mvwgetch</B>, routines read a character from
- the window. In no-delay mode, if no input is waiting, the value <B>ERR</B> is
+ 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
- text through to the program. Depending on the setting of <B>cbreak</B>, this
+ text through to the program. Depending on the setting of <STRONG>cbreak</STRONG>, this
is after one character (cbreak mode), or after the first newline
(nocbreak mode). In half-delay mode, the program waits until a charac-
ter is typed or the specified timeout has been reached.
- If <B>echo</B> is enabled, and the window is not a pad, then the character
+ If <STRONG>echo</STRONG> is enabled, and the window is not a pad, then the character
will also be echoed into the designated window according to the follow-
ing rules:
- <B>o</B> If the character is the current erase character, left arrow, or
+ <STRONG>o</STRONG> If the character is the current erase character, left arrow, or
backspace, the cursor is moved one space to the left and that
- screen position is erased as if <B>delch</B> had been called.
+ screen position is erased as if <STRONG>delch</STRONG> had been called.
- <B>o</B> If the character value is any other <B>KEY_</B> define, the user is alert-
- ed with a <B>beep</B> call.
+ <STRONG>o</STRONG> If the character value is any other <STRONG>KEY_</STRONG> define, the user is alert-
+ ed with a <STRONG>beep</STRONG> call.
- <B>o</B> If the character is a carriage-return, and if <B>nl</B> is enabled, it is
+ <STRONG>o</STRONG> If the character is a carriage-return, and if <STRONG>nl</STRONG> is enabled, it is
translated to a line-feed after echoing.
- <B>o</B> Otherwise the character is simply output to the screen.
+ <STRONG>o</STRONG> Otherwise the character is simply output to the screen.
If the window is not a pad, and it has been moved or modified since the
- last call to <B>wrefresh</B>, <B>wrefresh</B> will be called before another character
+ last call to <STRONG>wrefresh</STRONG>, <STRONG>wrefresh</STRONG> will be called before another character
is read.
</PRE><H3><a name="h3-Keypad-mode">Keypad mode</a></H3><PRE>
- If <B>keypad</B> is <B>TRUE</B>, and a function key is pressed, the token for that
+ 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:
- <B>o</B> The predefined function keys are listed in <B><curses.h></B> as macros
+ <STRONG>o</STRONG> The predefined function keys are listed in <STRONG><curses.h></STRONG> as macros
with values outside the range of 8-bit characters. Their names be-
- gin with <B>KEY_</B>.
+ gin with <STRONG>KEY_</STRONG>.
- <B>o</B> Other (user-defined) function keys which may be defined using <B>de-</B>
- <B><A HREF="define_key.3X.html">fine_key(3X)</A></B> have no names, but also are expected to have values
+ <STRONG>o</STRONG> Other (user-defined) function keys which may be defined using <STRONG>de-</STRONG>
+ <STRONG><A HREF="define_key.3x.html">fine_key(3x)</A></STRONG> have no names, but also are expected to have values
outside the range of 8-bit characters.
Thus, a variable intended to hold the return value of a function key
must be of short size or larger.
When a character that could be the beginning of a function key is re-
- ceived (which, on modern terminals, means an escape character), <B>curses</B>
+ ceived (which, on modern terminals, means an escape character), <STRONG>curses</STRONG>
sets a timer. If the remainder of the sequence does not come in within
the designated time, the character is passed through; otherwise, the
function key value is returned. For this reason, many terminals expe-
rience a delay between the time a user presses the escape key and the
escape is returned to the program.
- In <B>ncurses</B>, the timer normally expires after the value in <B>ESCDELAY</B> (see
- <B><A HREF="curs_variables.3X.html">curs_variables(3X)</A></B>). If <B>notimeout</B> is <B>TRUE</B>, the timer does not expire;
+ In <STRONG>ncurses</STRONG>, 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 no-
timeout mode after pressing the escape key until another key is
</PRE><H3><a name="h3-Ungetting-characters">Ungetting characters</a></H3><PRE>
- The <B>ungetch</B> routine places <I>ch</I> back onto the input queue to be returned
- by the next call to <B>wgetch</B>. There is just one input queue for all win-
+ 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 win-
dows.
</PRE><H3><a name="h3-Predefined-key-codes">Predefined key-codes</a></H3><PRE>
- The following special keys are defined in <B><curses.h></B>.
+ The following special keys are defined in <STRONG><curses.h></STRONG>.
- <B>o</B> Except for the special case <B>KEY_RESIZE</B>, it is necessary to enable
- <B>keypad</B> for <B>getch</B> to return these codes.
+ <STRONG>o</STRONG> Except for the special case <STRONG>KEY_RESIZE</STRONG>, it is necessary to enable
+ <STRONG>keypad</STRONG> for <STRONG>getch</STRONG> to return these codes.
- <B>o</B> Not all of these are necessarily supported on any particular termi-
+ <STRONG>o</STRONG> Not all of these are necessarily supported on any particular termi-
nal.
- <B>o</B> The naming convention may seem obscure, with some apparent mis-
+ <STRONG>o</STRONG> The naming convention may seem obscure, with some apparent mis-
spellings (such as "RSUME" for "resume"). The names correspond to
the long terminfo capability names for the keys, and were defined
long ago, in the 1980s.
- <I>Name</I> <I>Key</I> <I>name</I>
+ <EM>Name</EM> <EM>Key</EM> <EM>name</EM>
-------------------------------------------------
KEY_BREAK Break key
KEY_DOWN The four arrow keys ...
KEY_BACKSPACE Backspace
KEY_F0 Function keys; space for 64 keys
is reserved.
- KEY_F(<I>n</I>) For 0 <= <I>n</I> <= 63
+ KEY_F(<EM>n</EM>) For 0 <= <EM>n</EM> <= 63
KEY_DL Delete line
KEY_IL Insert line
KEY_DC Delete character
Keypad is arranged like this:
+-----+------+-------+
- | <B>A1</B> | <B>up</B> | <B>A3</B> |
+ | <STRONG>A1</STRONG> | <STRONG>up</STRONG> | <STRONG>A3</STRONG> |
+-----+------+-------+
- |<B>left</B> | <B>B2</B> | <B>right</B> |
+ |<STRONG>left</STRONG> | <STRONG>B2</STRONG> | <STRONG>right</STRONG> |
+-----+------+-------+
- | <B>C1</B> | <B>down</B> | <B>C3</B> |
+ | <STRONG>C1</STRONG> | <STRONG>down</STRONG> | <STRONG>C3</STRONG> |
+-----+------+-------+
- A few of these predefined values do <I>not</I> correspond to a real key:
+ A few of these predefined values do <EM>not</EM> correspond to a real key:
- <B>o</B> <B>KEY_RESIZE</B> is returned when the <B>SIGWINCH</B> signal has been detected
- (see <B><A HREF="curs_initscr.3X.html">initscr(3X)</A></B> and <B><A HREF="resizeterm.3X.html">resizeterm(3X)</A></B>). This code is returned
- whether or not <B>keypad</B> has been enabled.
+ <STRONG>o</STRONG> <STRONG>KEY_RESIZE</STRONG> is returned when the <STRONG>SIGWINCH</STRONG> signal has been detected
+ (see <STRONG><A HREF="curs_initscr.3x.html">initscr(3x)</A></STRONG> and <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG>). This code is returned
+ whether or not <STRONG>keypad</STRONG> has been enabled.
- <B>o</B> <B>KEY_MOUSE</B> is returned for mouse-events (see <B><A HREF="curs_mouse.3X.html">curs_mouse(3X)</A></B>). This
- code relies upon whether or not <B><A HREF="curs_inopts.3X.html">keypad(3X)</A></B> has been enabled, be-
- cause (e.g., with <I>xterm</I> mouse prototocol) ncurses must read escape
+ <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, be-
+ cause (e.g., with <EM>xterm</EM> mouse prototocol) ncurses must read escape
sequences, just like a function key.
</PRE><H3><a name="h3-Testing-key-codes">Testing key-codes</a></H3><PRE>
- The <B>has_key</B> routine takes a key-code value from the above list, and re-
- turns <B>TRUE</B> or <B>FALSE</B> according to whether the current terminal type rec-
+ The <STRONG>has_key</STRONG> routine takes a key-code value from the above list, and re-
+ turns <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG> according to whether the current terminal type rec-
ognizes a key with that value.
The library also supports these extensions:
- <B>define_key</B>
- defines a key-code for a given string (see <B><A HREF="define_key.3X.html">define_key(3X)</A></B>).
+ <STRONG>define_key</STRONG>
+ defines a key-code for a given string (see <STRONG><A HREF="define_key.3x.html">define_key(3x)</A></STRONG>).
- <B>key_defined</B>
+ <STRONG>key_defined</STRONG>
checks if there is a key-code defined for a given string (see
- <B><A HREF="key_defined.3X.html">key_defined(3X)</A></B>).
+ <STRONG><A HREF="key_defined.3x.html">key_defined(3x)</A></STRONG>).
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
- All routines return the integer <B>ERR</B> upon failure and an integer value
- other than <B>ERR</B> (<B>OK</B> in the case of <B>ungetch</B>) upon successful completion.
+ All routines return the integer <STRONG>ERR</STRONG> upon failure and an integer value
+ other than <STRONG>ERR</STRONG> (<STRONG>OK</STRONG> in the case of <STRONG>ungetch</STRONG>) upon successful completion.
- <B>ungetch</B>
- returns <B>ERR</B> if there is no more room in the FIFO.
+ <STRONG>ungetch</STRONG>
+ returns <STRONG>ERR</STRONG> if there is no more room in the FIFO.
- <B>wgetch</B>
- returns <B>ERR</B> if the window pointer is null, or if its timeout
+ <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 inter-
- rupted by a signal (<B>errno</B> will be set to <B>EINTR</B>).
+ rupted by a signal (<STRONG>errno</STRONG> will be set to <STRONG>EINTR</STRONG>).
Functions with a "mv" prefix first perform a cursor movement using
- <B>wmove</B>, and return an error if the position is outside the window, or if
+ <STRONG>wmove</STRONG>, and return an error if the position is outside the window, or if
the window pointer is null.
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., <B>KEY_EN-</B>
- <B>TER</B> versus control/M, <B>KEY_BACKSPACE</B> versus control/H. Some curses im-
+ Some keys may be the same as commonly used control keys, e.g., <STRONG>KEY_EN-</STRONG>
+ <STRONG>TER</STRONG> versus control/M, <STRONG>KEY_BACKSPACE</STRONG> versus control/H. Some curses im-
plementations may differ according to whether they treat these control
keys specially (and ignore the terminfo), or use the terminfo defini-
- tions. <B>Ncurses</B> uses the terminfo definition. If it says that <B>KEY_EN-</B>
- <B>TER</B> is control/M, <B>getch</B> will return <B>KEY_ENTER</B> when you press control/M.
+ tions. <STRONG>Ncurses</STRONG> uses the terminfo definition. If it says that <STRONG>KEY_EN-</STRONG>
+ <STRONG>TER</STRONG> is control/M, <STRONG>getch</STRONG> will return <STRONG>KEY_ENTER</STRONG> when you press control/M.
- Generally, <B>KEY_ENTER</B> denotes the character(s) sent by the <I>Enter</I> key on
+ Generally, <STRONG>KEY_ENTER</STRONG> denotes the character(s) sent by the <EM>Enter</EM> key on
the numeric keypad:
- <B>o</B> the terminal description lists the most useful keys,
+ <STRONG>o</STRONG> the terminal description lists the most useful keys,
- <B>o</B> the <I>Enter</I> 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,
- <B>o</B> depending on whether <B>nl</B> or <B>nonl</B> was called, pressing "Enter" on the
+ <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,
and finally
- <B>o</B> "Enter or send" is the standard description for this key.
+ <STRONG>o</STRONG> "Enter or send" is the standard description for this key.
- When using <B>getch</B>, <B>wgetch</B>, <B>mvgetch</B>, or <B>mvwgetch</B>, nocbreak mode
- (<B>nocbreak</B>) and echo mode (<B>echo</B>) should not be used at the same time.
+ 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 <B>getch</B>, <B>mvgetch</B>, and <B>mvwgetch</B> may be macros.
+ 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 ex-
tremely function-key-rich keyboard of the AT&T 7300, aka 3B1, aka Sa-
fari 4. Modern personal computers usually have only a small subset of
these. IBM PC-style consoles typically support little more than
- <B>KEY_UP</B>, <B>KEY_DOWN</B>, <B>KEY_LEFT</B>, <B>KEY_RIGHT</B>, <B>KEY_HOME</B>, <B>KEY_END</B>, <B>KEY_NPAGE</B>,
- <B>KEY_PPAGE</B>, and function keys 1 through 12. The Ins key is usually
- mapped to <B>KEY_IC</B>.
+ <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-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 <B>ERR</B> on failure, but specifies no error conditions.
+ they return <STRONG>ERR</STRONG> on failure, but specifies no error conditions.
- The echo behavior of these functions on input of <B>KEY_</B> or backspace
+ The echo behavior of these functions on input of <STRONG>KEY_</STRONG> or backspace
characters was not specified in the SVr4 documentation. This descrip-
tion is adopted from the XSI Curses standard.
- The behavior of <B>getch</B> and friends in the presence of handled signals is
+ 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 <B>read(2)</B>
+ 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.
- <B>KEY_MOUSE</B> is mentioned in XSI Curses, along with a few related terminfo
+ <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 im-
plementation in ncurses is an extension.
- <B>KEY_RESIZE</B> is an extension first implemented for ncurses. NetBSD curs-
+ <STRONG>KEY_RESIZE</STRONG> is an extension first implemented for ncurses. NetBSD curs-
es later added this extension.
Programmers concerned about portability should be prepared for either
- of two cases: (a) signal receipt does not interrupt <B>getch</B>; (b) signal
- receipt interrupts <B>getch</B> and causes it to return <B>ERR</B> with <B>errno</B> set to
- <B>EINTR</B>.
+ 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 <B>has_key</B> function is unique to <B>ncurses</B>. We recommend that any code
- using it be conditionalized on the <B>NCURSES_VERSION</B> feature macro.
+ The <STRONG>has_key</STRONG> function is unique to <STRONG>ncurses</STRONG>. We recommend that any code
+ using it be conditionalized on the <STRONG>NCURSES_VERSION</STRONG> feature macro.
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
- <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="curs_inopts.3X.html">curs_inopts(3X)</A></B>, <B><A HREF="curs_mouse.3X.html">curs_mouse(3X)</A></B>, <B><A HREF="curs_move.3X.html">curs_move(3X)</A></B>, <B>curs_out-</B>
- <B><A HREF="curs_outopts.3X.html">opts(3X)</A></B>, <B><A HREF="curs_refresh.3X.html">curs_refresh(3X)</A></B>, <B><A HREF="curs_variables.3X.html">curs_variables(3X)</A></B>, <B><A HREF="resizeterm.3X.html">resizeterm(3X)</A></B>.
+ <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>curs_out-</STRONG>
+ <STRONG><A HREF="curs_outopts.3x.html">opts(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 de-
- scribed in <B><A HREF="curs_get_wch.3X.html">curs_get_wch(3X)</A></B>.
+ scribed in <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>.
- <B><A HREF="curs_getch.3X.html">curs_getch(3X)</A></B>
+ <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
</PRE>
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