3 ****************************************************************************
4 * Copyright (c) 1998-2014,2015 Free Software Foundation, Inc. *
6 * Permission is hereby granted, free of charge, to any person obtaining a *
7 * copy of this software and associated documentation files (the *
8 * "Software"), to deal in the Software without restriction, including *
9 * without limitation the rights to use, copy, modify, merge, publish, *
10 * distribute, distribute with modifications, sublicense, and/or sell *
11 * copies of the Software, and to permit persons to whom the Software is *
12 * furnished to do so, subject to the following conditions: *
14 * The above copyright notice and this permission notice shall be included *
15 * in all copies or substantial portions of the Software. *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
20 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
23 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
25 * Except as contained in this notice, the name(s) of the above copyright *
26 * holders shall not be used in advertising or otherwise to promote the *
27 * sale, use or other dealings in this Software without prior written *
29 ****************************************************************************
30 * @Id: curs_getch.3x,v 1.44 2015/12/20 01:43:03 tom Exp @
32 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
35 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
36 <meta name="generator" content="Manpage converted by man2html - see http://invisible-island.net/scripts/readme.html#others_scripts">
37 <TITLE>curs_getch 3x</TITLE>
38 <link rev=made href="mailto:bug-ncurses@gnu.org">
39 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
42 <H1 class="no-header">curs_getch 3x</H1>
44 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, <STRONG>mvwgetch</STRONG>, <STRONG>ungetch</STRONG>, <STRONG>has_key</STRONG> - get
51 (or push back) characters from <STRONG>curses</STRONG> terminal keyboard
54 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
55 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
57 <STRONG>int</STRONG> <STRONG>getch(void);</STRONG>
58 <STRONG>int</STRONG> <STRONG>wgetch(WINDOW</STRONG> <STRONG>*</STRONG><EM>win);</EM>
59 <STRONG>int</STRONG> <STRONG>mvgetch(int</STRONG> <EM>y</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>x</EM><STRONG>);</STRONG>
60 <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>
61 <STRONG>int</STRONG> <STRONG>ungetch(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
62 <STRONG>int</STRONG> <STRONG>has_key(int</STRONG> <EM>ch</EM><STRONG>);</STRONG>
65 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
67 </PRE><H3><a name="h3-Reading-characters">Reading characters</a></H3><PRE>
68 The <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG> and <STRONG>mvwgetch</STRONG>, routines read a
69 character from the window. In no-delay mode, if no input
70 is waiting, the value <STRONG>ERR</STRONG> is returned. In delay mode, the
71 program waits until the system passes text through to the
72 program. Depending on the setting of <STRONG>cbreak</STRONG>, this is af-
73 ter one character (cbreak mode), or after the first new-
74 line (nocbreak mode). In half-delay mode, the program
75 waits until a character is typed or the specified timeout
78 If <STRONG>echo</STRONG> is enabled, and the window is not a pad, then the
79 character will also be echoed into the designated window
80 according to the following rules:
82 <STRONG>o</STRONG> If the character is the current erase character, left
83 arrow, or backspace, the cursor is moved one space to
84 the left and that screen position is erased as if
85 <STRONG>delch</STRONG> had been called.
87 <STRONG>o</STRONG> If the character value is any other <STRONG>KEY_</STRONG> define, the
88 user is alerted with a <STRONG>beep</STRONG> call.
90 <STRONG>o</STRONG> If the character is a carriage-return, and if <STRONG>nl</STRONG> is
91 enabled, it is translated to a line-feed after echo-
94 <STRONG>o</STRONG> Otherwise the character is simply output to the
97 If the window is not a pad, and it has been moved or modi-
98 fied since the last call to <STRONG>wrefresh</STRONG>, <STRONG>wrefresh</STRONG> will be
99 called before another character is read.
102 </PRE><H3><a name="h3-Keypad-mode">Keypad mode</a></H3><PRE>
103 If <STRONG>keypad</STRONG> is <STRONG>TRUE</STRONG>, and a function key is pressed, the to-
104 ken for that function key is returned instead of the raw
105 characters. Possible function keys are defined in <STRONG><curs-</STRONG>
106 <STRONG>es.h></STRONG> as macros with values outside the range of 8-bit
107 characters whose names begin with <STRONG>KEY_</STRONG>. Thus, a variable
108 intended to hold the return value of a function key must
109 be of short size or larger.
111 When a character that could be the beginning of a function
112 key is received (which, on modern terminals, means an es-
113 cape character), <STRONG>curses</STRONG> sets a timer. If the remainder of
114 the sequence does not come in within the designated time,
115 the character is passed through; otherwise, the function
116 key value is returned. For this reason, many terminals
117 experience a delay between the time a user presses the es-
118 cape key and the escape is returned to the program.
121 </PRE><H3><a name="h3-Ungetting-characters">Ungetting characters</a></H3><PRE>
122 The <STRONG>ungetch</STRONG> routine places <EM>ch</EM> back onto the input queue to
123 be returned by the next call to <STRONG>wgetch</STRONG>. There is just one
124 input queue for all windows.
127 </PRE><H3><a name="h3-Predefined-key-codes">Predefined key-codes</a></H3><PRE>
128 The following special keys are defined in <STRONG><curses.h></STRONG>.
130 <STRONG>o</STRONG> Except for the special case <STRONG>KEY_RESIZE</STRONG>, it is neces-
131 sary to enable <STRONG>keypad</STRONG> for <STRONG>getch</STRONG> to return these codes.
133 <STRONG>o</STRONG> Not all of these are necessarily supported on any par-
136 <STRONG>o</STRONG> The naming convention may seem obscure, with some ap-
137 parent misspellings (such as "RSUME" for "resume").
138 The names correspond to the long terminfo capability
139 names for the keys, and were defined long ago, in the
142 <EM>Name</EM> <EM>Key</EM> <EM>name</EM>
143 -------------------------------------------------
145 KEY_DOWN The four arrow keys ...
149 KEY_HOME Home key (upward+left arrow)
150 KEY_BACKSPACE Backspace
151 KEY_F0 Function keys; space for 64 keys
153 KEY_F(<EM>n</EM>) For 0 <= <EM>n</EM> <= 63
156 KEY_DC Delete character
157 KEY_IC Insert char or enter insert mode
158 KEY_EIC Exit insert char mode
159 KEY_CLEAR Clear screen
160 KEY_EOS Clear to end of screen
161 KEY_EOL Clear to end of line
162 KEY_SF Scroll 1 line forward
163 KEY_SR Scroll 1 line backward (reverse)
165 KEY_PPAGE Previous page
168 KEY_CATAB Clear all tabs
169 KEY_ENTER Enter or send
170 KEY_SRESET Soft (partial) reset
171 KEY_RESET Reset or hard reset
172 KEY_PRINT Print or copy
173 KEY_LL Home down or bottom (lower left)
174 KEY_A1 Upper left of keypad
175 KEY_A3 Upper right of keypad
176 KEY_B2 Center of keypad
177 KEY_C1 Lower left of keypad
178 KEY_C3 Lower right of keypad
179 KEY_BTAB Back tab key
180 KEY_BEG Beg(inning) key
181 KEY_CANCEL Cancel key
184 KEY_COMMAND Cmd (command) key
186 KEY_CREATE Create key
192 KEY_MESSAGE Message key
193 KEY_MOUSE Mouse event read
195 KEY_NEXT Next object key
197 KEY_OPTIONS Options key
198 KEY_PREVIOUS Previous object key
200 KEY_REFERENCE Ref(erence) key
201 KEY_REFRESH Refresh key
202 KEY_REPLACE Replace key
203 KEY_RESIZE Screen resized
204 KEY_RESTART Restart key
205 KEY_RESUME Resume key
207 KEY_SBEG Shifted beginning key
208 KEY_SCANCEL Shifted cancel key
209 KEY_SCOMMAND Shifted command key
210 KEY_SCOPY Shifted copy key
211 KEY_SCREATE Shifted create key
212 KEY_SDC Shifted delete char key
213 KEY_SDL Shifted delete line key
214 KEY_SELECT Select key
215 KEY_SEND Shifted end key
216 KEY_SEOL Shifted clear line key
217 KEY_SEXIT Shifted exit key
218 KEY_SFIND Shifted find key
219 KEY_SHELP Shifted help key
220 KEY_SHOME Shifted home key
221 KEY_SIC Shifted input key
222 KEY_SLEFT Shifted left arrow key
223 KEY_SMESSAGE Shifted message key
224 KEY_SMOVE Shifted move key
225 KEY_SNEXT Shifted next key
226 KEY_SOPTIONS Shifted options key
227 KEY_SPREVIOUS Shifted prev key
228 KEY_SPRINT Shifted print key
229 KEY_SREDO Shifted redo key
230 KEY_SREPLACE Shifted replace key
231 KEY_SRIGHT Shifted right arrow
232 KEY_SRSUME Shifted resume key
233 KEY_SSAVE Shifted save key
234 KEY_SSUSPEND Shifted suspend key
235 KEY_SUNDO Shifted undo key
236 KEY_SUSPEND Suspend key
239 Keypad is arranged like this:
241 +-----+------+-------+
242 | <STRONG>A1</STRONG> | <STRONG>up</STRONG> | <STRONG>A3</STRONG> |
243 +-----+------+-------+
244 |<STRONG>left</STRONG> | <STRONG>B2</STRONG> | <STRONG>right</STRONG> |
245 +-----+------+-------+
246 | <STRONG>C1</STRONG> | <STRONG>down</STRONG> | <STRONG>C3</STRONG> |
247 +-----+------+-------+
248 A few of these predefined values do <EM>not</EM> correspond to a
251 <STRONG>o</STRONG> <STRONG>KEY_RESIZE</STRONG> is returned when the <STRONG>SIGWINCH</STRONG> signal has
252 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>).
253 This code is returned whether or not <STRONG>keypad</STRONG> has been
256 <STRONG>o</STRONG> <STRONG>KEY_MOUSE</STRONG> is returned for mouse-events (see
257 <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG>). This code relies upon whether or not
258 <STRONG><A HREF="keypad.3x.html">keypad(3x)</A></STRONG> has been enabled, because (e.g., with <EM>xterm</EM>
259 mouse prototocol) ncurses must read escape sequences,
260 just like a function key.
263 </PRE><H3><a name="h3-Testing-key-codes">Testing key-codes</a></H3><PRE>
264 The <STRONG>has_key</STRONG> routine takes a key-code value from the above
265 list, and returns <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG> according to whether the
266 current terminal type recognizes a key with that value.
268 The library also supports these extensions:
270 <STRONG>define_key</STRONG>
271 defines a key-code for a given string (see <STRONG>de-</STRONG>
272 <STRONG><A HREF="define_key.3x.html">fine_key(3x)</A></STRONG>).
274 <STRONG>key_defined</STRONG>
275 checks if there is a key-code defined for a given
276 string (see <STRONG><A HREF="key_defined.3x.html">key_defined(3x)</A></STRONG>).
279 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
280 All routines return the integer <STRONG>ERR</STRONG> upon failure and an
281 integer value other than <STRONG>ERR</STRONG> (<STRONG>OK</STRONG> in the case of ungetch())
282 upon successful completion.
284 <STRONG>ungetch</STRONG>
285 returns ERR if there is no more room in the FIFO.
287 <STRONG>wgetch</STRONG>
288 returns ERR if the window pointer is null, or if
289 its timeout expires without having any data.
291 Functions with a "mv" prefix first perform a cursor move-
292 ment using <STRONG>wmove</STRONG>, and return an error if the position is
293 outside the window, or if the window pointer is null.
296 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
297 Use of the escape key by a programmer for a single charac-
298 ter function is discouraged, as it will cause a delay of
299 up to one second while the keypad code looks for a follow-
300 ing function-key sequence.
302 Some keys may be the same as commonly used control keys,
303 e.g., <STRONG>KEY_ENTER</STRONG> versus control/M, <STRONG>KEY_BACKSPACE</STRONG> versus
304 control/H. Some curses implementations may differ accord-
305 ing to whether they treat these control keys specially
306 (and ignore the terminfo), or use the terminfo defini-
307 tions. <STRONG>Ncurses</STRONG> uses the terminfo definition. If it says
308 that <STRONG>KEY_ENTER</STRONG> is control/M, <STRONG>getch</STRONG> will return <STRONG>KEY_ENTER</STRONG>
309 when you press control/M.
311 Generally, <STRONG>KEY_ENTER</STRONG> denotes the character(s) sent by the
312 <EM>Enter</EM> key on the numeric keypad:
314 <STRONG>o</STRONG> the terminal description lists the most useful keys,
316 <STRONG>o</STRONG> the <EM>Enter</EM> key on the regular keyboard is already han-
317 dled by the standard ASCII characters for carriage-re-
320 <STRONG>o</STRONG> depending on whether <STRONG>nl</STRONG> or <STRONG>nonl</STRONG> was called, pressing
321 "Enter" on the regular keyboard may return either a
322 carriage-return or line-feed, and finally
324 <STRONG>o</STRONG> "Enter or send" is the standard description for this
327 When using <STRONG>getch</STRONG>, <STRONG>wgetch</STRONG>, <STRONG>mvgetch</STRONG>, or <STRONG>mvwgetch</STRONG>, nocbreak
328 mode (<STRONG>nocbreak</STRONG>) and echo mode (<STRONG>echo</STRONG>) should not be used at
329 the same time. Depending on the state of the tty driver
330 when each character is typed, the program may produce un-
333 Note that <STRONG>getch</STRONG>, <STRONG>mvgetch</STRONG>, and <STRONG>mvwgetch</STRONG> may be macros.
335 Historically, the set of keypad macros was largely defined
336 by the extremely function-key-rich keyboard of the AT&T
337 7300, aka 3B1, aka Safari 4. Modern personal computers
338 usually have only a small subset of these. IBM PC-style
339 consoles typically support little more than <STRONG>KEY_UP</STRONG>,
340 <STRONG>KEY_DOWN</STRONG>, <STRONG>KEY_LEFT</STRONG>, <STRONG>KEY_RIGHT</STRONG>, <STRONG>KEY_HOME</STRONG>, <STRONG>KEY_END</STRONG>,
341 <STRONG>KEY_NPAGE</STRONG>, <STRONG>KEY_PPAGE</STRONG>, and function keys 1 through 12. The
342 Ins key is usually mapped to <STRONG>KEY_IC</STRONG>.
345 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
346 The *get* functions are described in the XSI Curses stan-
347 dard, Issue 4. They read single-byte characters only.
348 The standard specifies that they return <STRONG>ERR</STRONG> on failure,
349 but specifies no error conditions.
351 The echo behavior of these functions on input of <STRONG>KEY_</STRONG> or
352 backspace characters was not specified in the SVr4 docu-
353 mentation. This description is adopted from the XSI Curs-
356 The behavior of <STRONG>getch</STRONG> and friends in the presence of han-
357 dled signals is unspecified in the SVr4 and XSI Curses
358 documentation. Under historical curses implementations,
359 it varied depending on whether the operating system's im-
360 plementation of handled signal receipt interrupts a
361 <STRONG>read(2)</STRONG> call in progress or not, and also (in some imple-
362 mentations) depending on whether an input timeout or non-
363 blocking mode has been set.
365 <STRONG>KEY_MOUSE</STRONG> is mentioned in XSI Curses, along with a few re-
366 lated terminfo capabilities, but no higher-level functions
367 use the feature. The implementation in ncurses is an ex-
370 <STRONG>KEY_RESIZE</STRONG> is an extension first implemented for ncurses.
371 NetBSD curses later added this extension.
373 Programmers concerned about portability should be prepared
374 for either of two cases: (a) signal receipt does not in-
375 terrupt <STRONG>getch</STRONG>; (b) signal receipt interrupts <STRONG>getch</STRONG> and
376 causes it to return ERR with <STRONG>errno</STRONG> set to <STRONG>EINTR</STRONG>. Under
377 the <STRONG>ncurses</STRONG> implementation, handled signals never inter-
378 rupt <STRONG>getch</STRONG>.
380 The <STRONG>has_key</STRONG> function is unique to <STRONG>ncurses</STRONG>. We recommend
381 that any code using it be conditionalized on the <STRONG>NCURS-</STRONG>
382 <STRONG>ES_VERSION</STRONG> feature macro.
385 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
386 <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>,
387 <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>
388 <STRONG><A HREF="resizeterm.3x.html">sizeterm(3x)</A></STRONG>.
390 Comparable functions in the wide-character (ncursesw) li-
391 brary are described in <STRONG><A HREF="curs_get_wch.3x.html">curs_get_wch(3x)</A></STRONG>.
395 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
399 <li><a href="#h2-NAME">NAME</a></li>
400 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
401 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
403 <li><a href="#h3-Reading-characters">Reading characters</a></li>
404 <li><a href="#h3-Keypad-mode">Keypad mode</a></li>
405 <li><a href="#h3-Ungetting-characters">Ungetting characters</a></li>
406 <li><a href="#h3-Predefined-key-codes">Predefined key-codes</a></li>
407 <li><a href="#h3-Testing-key-codes">Testing key-codes</a></li>
410 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
411 <li><a href="#h2-NOTES">NOTES</a></li>
412 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
413 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>