1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
|
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<!--
* t
****************************************************************************
* Copyright (c) 1998-2010,2011 Free Software Foundation, Inc. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the *
* "Software"), to deal in the Software without restriction, including *
* without limitation the rights to use, copy, modify, merge, publish, *
* distribute, distribute with modifications, sublicense, and/or sell *
* copies of the Software, and to permit persons to whom the Software is *
* furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included *
* in all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
* IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
* THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
* *
* Except as contained in this notice, the name(s) of the above copyright *
* holders shall not be used in advertising or otherwise to promote the *
* sale, use or other dealings in this Software without prior written *
* authorization. *
****************************************************************************
* @Id: curs_getch.3x,v 1.36 2011/01/22 19:38:51 tom Exp @
-->
<HTML>
<HEAD>
<TITLE>curs_getch 3x</TITLE>
<link rev=made href="mailto:bug-ncurses@gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</HEAD>
<BODY>
<H1>curs_getch 3x</H1>
<HR>
<PRE>
<!-- Manpage converted by man2html 3.0.1 -->
<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>NAME</H2><PRE>
<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>SYNOPSIS</H2><PRE>
<STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
<STRONG>int</STRONG> <STRONG>getch(void);</STRONG>
<STRONG>int</STRONG> <STRONG>wgetch(WINDOW</STRONG> <STRONG>*win);</STRONG>
<STRONG>int</STRONG> <STRONG>mvgetch(int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x);</STRONG>
<STRONG>int</STRONG> <STRONG>mvwgetch(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>int</STRONG> <STRONG>y,</STRONG> <STRONG>int</STRONG> <STRONG>x);</STRONG>
<STRONG>int</STRONG> <STRONG>ungetch(int</STRONG> <STRONG>ch);</STRONG>
<STRONG>int</STRONG> <STRONG>has_key(int</STRONG> <STRONG>ch);</STRONG>
</PRE>
<H2>DESCRIPTION</H2><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 text through to the
program. Depending on the setting of <STRONG>cbreak</STRONG>, this is af-
ter 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 <STRONG>noecho</STRONG> 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
<STRONG>delch</STRONG> had been called. If the character value is any oth-
er <STRONG>KEY_</STRONG> define, the user is alerted with a <STRONG>beep</STRONG> 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 <STRONG>wrefresh</STRONG>, <STRONG>wrefresh</STRONG> will be
called before another character is read.
If <STRONG>keypad</STRONG> is <STRONG>TRUE</STRONG>, and a function key is pressed, the to-
ken for that function key is returned instead of the raw
characters. Possible function keys are defined in <STRONG><curs-</STRONG>
<STRONG>es.h></STRONG> as macros with values outside the range of 8-bit
characters whose names begin with <STRONG>KEY_</STRONG>. 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 es-
cape 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
experience a delay between the time a user presses the es-
cape key and the escape is returned to the program.
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.
<STRONG>Function</STRONG> <STRONG>Keys</STRONG>
The following function keys, defined in <STRONG><curses.h></STRONG>, might
be returned by <STRONG>getch</STRONG> if <STRONG>keypad</STRONG> has been enabled. Note
that not all of these are necessarily supported on any
particular terminal.
<EM>Name</EM> <EM>Key</EM> <EM>name</EM>
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(<EM>n</EM>) For 0 <= <EM>n</EM> <= 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:
+-----+------+-------+
| <STRONG>A1</STRONG> | <STRONG>up</STRONG> | <STRONG>A3</STRONG> |
+-----+------+-------+
|<STRONG>left</STRONG> | <STRONG>B2</STRONG> | <STRONG>right</STRONG> |
+-----+------+-------+
| <STRONG>C1</STRONG> | <STRONG>down</STRONG> | <STRONG>C3</STRONG> |
+-----+------+-------+
The <STRONG>has_key</STRONG> routine takes a key value from the above list,
and returns TRUE or FALSE according to whether the current
terminal type recognizes a key with that value. Note that
a few values do not correspond to a real key, e.g.,
<STRONG>KEY_RESIZE</STRONG> and <STRONG>KEY_MOUSE</STRONG>. See <STRONG><A HREF="resizeterm.3x.html">resizeterm(3x)</A></STRONG> for more de-
tails about <STRONG>KEY_RESIZE</STRONG>, and <STRONG><A HREF="curs_mouse.3x.html">curs_mouse(3x)</A></STRONG> for a discus-
sion of <STRONG>KEY_MOUSE</STRONG>.
</PRE>
<H2>RETURN VALUE</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())
upon successful completion.
<STRONG>ungetch</STRONG>
returns an error if there is no more room in
the FIFO.
<STRONG>wgetch</STRONG>
returns an error if the window pointer is
null, or if its timeout expires without having
any data.
Functions with a "mv" prefix first perform a cursor move-
ment using <STRONG>wmove</STRONG>, and return an error if the position is
outside the window, or if the window pointer is null.
</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.
Note that some keys may be the same as commonly used con-
trol 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 spe-
cially (and ignore the terminfo), or use the terminfo def-
initions. <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/M.
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 han-
dled by the standard ASCII characters for carriage-re-
turn 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, 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, the program may produce un-
desirable 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 mapped to <STRONG>KEY_IC</STRONG>.
</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 <STRONG>ERR</STRONG> on failure,
but specifies no error conditions.
The echo behavior of these functions on input of <STRONG>KEY_</STRONG> or
backspace characters was not specified in the SVr4 docu-
mentation. This description is adopted from the XSI Curs-
es standard.
The behavior of <STRONG>getch</STRONG> 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 im-
plementation of handled signal receipt interrupts a
<STRONG><A HREF="read.2.html">read(2)</A></STRONG> call in progress or not, and also (in some imple-
mentations) depending on whether an input timeout or non-
blocking mode has been set.
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>.
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>
<STRONG>ES_VERSION</STRONG> feature macro.
</PRE>
<H2>SEE ALSO</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>.
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>.
<STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>
</PRE>
<HR>
<ADDRESS>
Man(1) output converted with
<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
</ADDRESS>
</BODY>
</HTML>
|
