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<HTML>
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<PRE>
<!-- Manpage converted by man2html 3.0.1 -->
</PRE>
<H2>NAME</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
</PRE>
<H2>SYNOPSIS</H2><PRE>
<B>#include</B> <B><curses.h></B>
<B>int</B> <B>getch(void);</B>
<B>int</B> <B>wgetch(WINDOW</B> <B>*win);</B>
<B>int</B> <B>mvgetch(int</B> <B>y,</B> <B>int</B> <B>x);</B>
<B>int</B> <B>mvwgetch(WINDOW</B> <B>*win,</B> <B>int</B> <B>y,</B> <B>int</B> <B>x);</B>
<B>int</B> <B>ungetch(int</B> <B>ch);</B>
<B>int</B> <B>has_key(int</B> <B>ch);</B>
</PRE>
<H2>DESCRIPTION</H2><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 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 is
after one character (cbreak mode), or after the first new-
line (nocbreak mode). In half-delay mode, the program
waits until a character is typed or the specified timeout
has been reached.
Unless <B>noecho</B> has been set, then the character will also
be echoed into the designated window according to the fol-
lowing rules: If the character is the current erase char-
acter, 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. If the character value is any
other <B>KEY_</B> define, the user is alerted with a <B>beep</B> call.
Otherwise the character is simply output to the screen.
If the window is not a pad, and it has been moved or modi-
fied since the last call to <B>wrefresh</B>, <B>wrefresh</B> will be
called before another character is read.
If <B>keypad</B> is <B>TRUE</B>, and a function key is pressed, the
token for that function key is returned instead of the raw
characters. Possible function keys are defined in
<B><curses.h></B> as macros with values outside the range of
8-bit characters whose names begin with <B>KEY_.</B> 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 received (which, on modern terminals, means an
escape character), <B>curses</B> 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 experience a delay between the time a user
presses the escape key and the escape is returned to the
program.
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>. Note that there
is, in effect, just one input queue for all windows.
<B>Function</B> <B>Keys</B>
The following function keys, defined in <B><curses.h></B>, might
be returned by <B>getch</B> if <B>keypad</B> has been enabled. Note
that not all of these are necessarily supported on any
particular terminal.
<I>Name</I> <I>Key</I> <I>name</I>
KEY_BREAK Break key
KEY_DOWN The four arrow keys ...
KEY_UP
KEY_LEFT
KEY_RIGHT
KEY_HOME Home key (upward+left arrow)
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_DL Delete line
KEY_IL Insert line
KEY_DC Delete character
KEY_IC Insert char or enter insert mode
KEY_EIC Exit insert char mode
KEY_CLEAR Clear screen
KEY_EOS Clear to end of screen
KEY_EOL Clear to end of line
KEY_SF Scroll 1 line forward
KEY_SR Scroll 1 line backward (reverse)
KEY_NPAGE Next page
KEY_PPAGE Previous page
KEY_STAB Set tab
KEY_CTAB Clear tab
KEY_CATAB Clear all tabs
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
KEY_B2 Center of keypad
KEY_C1 Lower left of keypad
KEY_C3 Lower right of keypad
KEY_BTAB Back tab key
KEY_BEG Beg(inning) key
KEY_CANCEL Cancel key
KEY_CLOSE Close key
KEY_COMMAND Cmd (command) key
KEY_COPY Copy key
KEY_CREATE Create key
KEY_END End key
KEY_EXIT Exit key
KEY_FIND Find key
KEY_HELP Help key
KEY_MARK Mark key
KEY_MESSAGE Message key
KEY_MOUSE Mouse event read
KEY_MOVE Move key
KEY_NEXT Next object key
KEY_OPEN Open key
KEY_OPTIONS Options key
KEY_PREVIOUS Previous object key
KEY_REDO Redo key
KEY_REFERENCE Ref(erence) key
KEY_REFRESH Refresh key
KEY_REPLACE Replace key
KEY_RESIZE Screen resized
KEY_RESTART Restart key
KEY_RESUME Resume key
KEY_SAVE Save key
KEY_SBEG Shifted beginning key
KEY_SCANCEL Shifted cancel key
KEY_SCOMMAND Shifted command key
KEY_SCOPY Shifted copy key
KEY_SCREATE Shifted create key
KEY_SDC Shifted delete char key
KEY_SDL Shifted delete line key
KEY_SELECT Select key
KEY_SEND Shifted end key
KEY_SEOL Shifted clear line key
KEY_SEXIT Shifted exit key
KEY_SFIND Shifted find key
KEY_SHELP Shifted help key
KEY_SHOME Shifted home key
KEY_SIC Shifted input key
KEY_SLEFT Shifted left arrow key
KEY_SMESSAGE Shifted message key
KEY_SMOVE Shifted move key
KEY_SNEXT Shifted next key
KEY_SOPTIONS Shifted options key
KEY_SPREVIOUS Shifted prev key
KEY_SPRINT Shifted print key
KEY_SREDO Shifted redo key
KEY_SREPLACE Shifted replace key
KEY_SRIGHT Shifted right arrow
KEY_SRSUME Shifted resume key
KEY_SSAVE Shifted save key
KEY_SSUSPEND Shifted suspend key
KEY_SUNDO Shifted undo key
KEY_SUSPEND Suspend key
KEY_UNDO Undo key
Keypad is arranged like this:
+-----+------+-------+
| <B>A1</B> | <B>up</B> | <B>A3</B> |
+-----+------+-------+
|<B>left</B> | <B>B2</B> | <B>right</B> |
+-----+------+-------+
| <B>C1</B> | <B>down</B> | <B>C3</B> |
+-----+------+-------+
The <B>has_key</B> routine takes a key value from the above list,
and returns TRUE or FALSE according as the current termi-
nal type recognizes a key with that value.
</PRE>
<H2>RETURN VALUE</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 ungetch())
upon successful completion.
</PRE>
<H2>NOTES</H2><PRE>
Use of the escape key by a programmer for a single charac-
ter function is discouraged, as it will cause a delay of
up to one second while the keypad code looks for a follow-
ing function-key sequence.
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. 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.
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 <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>.
</PRE>
<H2>PORTABILITY</H2><PRE>
The *get* functions are described in the XSI Curses stan-
dard, Issue 4. They read single-byte characters only.
The standard specifies that they return <B>ERR</B> on failure,
but specifies no error conditions.
The echo behavior of these functions on input of <B>KEY_</B> or
backspace characters was not specified in the SVr4 docu-
mentation. This description is adopted from the XSI
Curses standard.
The behavior of <B>getch</B> and friends in the presence of han-
dled 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><A HREF="read.2.html">read(2)</A></B> call in progress or not, and also (in some imple-
mentations) depending on whether an input timeout or non-
blocking mode hsd been set.
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 ERR with <B>errno</B> set to <B>EINTR</B>. Under
the <B>ncurses</B> implementation, handled signals never inter-
rupt <B>getch</B>.
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.
</PRE>
<H2>SEE ALSO</H2><PRE>
<B><A HREF="ncurses.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><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></B>. <B><A HREF="resizeterm.3x.html">resizeterm(3x)</A></B>.
</PRE>
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