* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
- * @Id: curs_getch.3x,v 1.45 2016/05/15 01:05:18 tom Exp @
+ * @Id: curs_getch.3x,v 1.49 2016/10/15 16:44:01 tom Exp @
-->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML>
experience a delay between the time a user presses the es-
cape 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 <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 pressed.
+
</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
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_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_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
real key:
<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">
curs_initscr(3x)</A></STRONG> and <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG>).
+ 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.
<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="keypad.3x.html">keypad(3x)</A></STRONG> has been enabled, because (e.g., with <EM>xterm</EM>
+ <STRONG><A HREF="curs_inopts.3x.html">keypad(3x)</A></STRONG> has been enabled, because (e.g., with <EM>xterm</EM>
mouse prototocol) ncurses must read escape sequences,
just like a function key.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
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 ungetch())
+ integer value other than <STRONG>ERR</STRONG> (<STRONG>OK</STRONG> in the case of <STRONG>ungetch</STRONG>)
upon successful completion.
<STRONG>ungetch</STRONG>
<STRONG>wgetch</STRONG>
returns ERR if the window pointer is null, or if
- its timeout expires without having any data.
+ 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>).
Functions with a "mv" prefix first perform a cursor move-
ment using <STRONG>wmove</STRONG>, and return an error if the position is
Programmers concerned about portability should be prepared
for either of two cases: (a) signal receipt does not in-
terrupt <STRONG>getch</STRONG>; (b) signal receipt interrupts <STRONG>getch</STRONG> and
- causes it to return ERR with <STRONG>errno</STRONG> set to <STRONG>EINTR</STRONG>. Under
- the <STRONG>ncurses</STRONG> implementation, handled signals never inter-
- rupt <STRONG>getch</STRONG>.
+ causes it to return ERR 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 using it be conditionalized on the <STRONG>NCURS-</STRONG>
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
<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_outopts.3x.html">curs_outopts(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_refresh.3x.html">curs_refresh(3x)</A></STRONG>, <STRONG>re-</STRONG>
- <STRONG><A HREF="resizeterm.3x.html">sizeterm(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_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) li-
brary are described in <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>.
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