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43 <H1 class="no-header">curs_inopts 3x 2023-08-12 ncurses 6.4 Library calls</H1>
45 <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>
50 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
51 <STRONG>cbreak</STRONG>, <STRONG>echo</STRONG>, <STRONG>halfdelay</STRONG>, <STRONG>intrflush</STRONG>, <STRONG>is_cbreak</STRONG>, <STRONG>is_echo</STRONG>, <STRONG>is_nl</STRONG>, <STRONG>is_raw</STRONG>,
52 <STRONG>keypad</STRONG>, <STRONG>meta</STRONG>, <STRONG>nl</STRONG>, <STRONG>nocbreak</STRONG>, <STRONG>nodelay</STRONG>, <STRONG>noecho</STRONG>, <STRONG>nonl</STRONG>, <STRONG>noqiflush</STRONG>, <STRONG>noraw</STRONG>,
53 <STRONG>notimeout</STRONG>, <STRONG>qiflush</STRONG>, <STRONG>raw</STRONG>, <STRONG>timeout</STRONG>, <STRONG>wtimeout</STRONG>, <STRONG>typeahead</STRONG> - <STRONG>curses</STRONG> input
57 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
58 <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
60 <STRONG>int</STRONG> <STRONG>cbreak(void);</STRONG>
61 <STRONG>int</STRONG> <STRONG>nocbreak(void);</STRONG>
63 <STRONG>int</STRONG> <STRONG>echo(void);</STRONG>
64 <STRONG>int</STRONG> <STRONG>noecho(void);</STRONG>
66 <STRONG>int</STRONG> <STRONG>intrflush(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>bool</STRONG> <EM>bf</EM><STRONG>);</STRONG>
67 <STRONG>int</STRONG> <STRONG>keypad(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>bool</STRONG> <EM>bf</EM><STRONG>);</STRONG>
68 <STRONG>int</STRONG> <STRONG>meta(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>bool</STRONG> <EM>bf</EM><STRONG>);</STRONG>
69 <STRONG>int</STRONG> <STRONG>nodelay(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>bool</STRONG> <EM>bf</EM><STRONG>);</STRONG>
70 <STRONG>int</STRONG> <STRONG>notimeout(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>bool</STRONG> <EM>bf</EM><STRONG>);</STRONG>
72 <STRONG>int</STRONG> <STRONG>nl(void);</STRONG>
73 <STRONG>int</STRONG> <STRONG>nonl(void);</STRONG>
75 <STRONG>int</STRONG> <STRONG>raw(void);</STRONG>
76 <STRONG>int</STRONG> <STRONG>noraw(void);</STRONG>
78 <STRONG>void</STRONG> <STRONG>qiflush(void);</STRONG>
79 <STRONG>void</STRONG> <STRONG>noqiflush(void);</STRONG>
81 <STRONG>int</STRONG> <STRONG>halfdelay(int</STRONG> <EM>tenths</EM><STRONG>);</STRONG>
82 <STRONG>void</STRONG> <STRONG>timeout(int</STRONG> <EM>delay</EM><STRONG>);</STRONG>
83 <STRONG>void</STRONG> <STRONG>wtimeout(WINDOW</STRONG> <STRONG>*</STRONG><EM>win</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>delay</EM><STRONG>);</STRONG>
85 <STRONG>int</STRONG> <STRONG>typeahead(int</STRONG> <EM>fd</EM><STRONG>);</STRONG>
88 <STRONG>int</STRONG> <STRONG>is_cbreak(void);</STRONG>
89 <STRONG>int</STRONG> <STRONG>is_echo(void);</STRONG>
90 <STRONG>int</STRONG> <STRONG>is_nl(void);</STRONG>
91 <STRONG>int</STRONG> <STRONG>is_raw(void);</STRONG>
94 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
95 The <STRONG>ncurses</STRONG> library provides several functions which let an application
96 change the way input from the terminal is handled. Some are global,
97 applying to all windows. Others apply only to a specific window. Win-
98 dow-specific settings are not automatically applied to new or derived
99 windows. An application must apply these to each window, if the same
103 </PRE><H3><a name="h3-cbreak_nocbreak">cbreak/nocbreak</a></H3><PRE>
104 Normally, the tty driver buffers typed characters until a newline or
105 carriage return is typed. The <STRONG>cbreak</STRONG> routine disables line buffering
106 and erase/kill character-processing (interrupt and flow control charac-
107 ters are unaffected), making characters typed by the user immediately
108 available to the program. The <STRONG>nocbreak</STRONG> routine returns the terminal to
109 normal (cooked) mode.
111 Initially the terminal may or may not be in <STRONG>cbreak</STRONG> mode, as the mode is
112 inherited; therefore, a program should call <STRONG>cbreak</STRONG> or <STRONG>nocbreak</STRONG> explic-
113 itly. Most interactive programs using <STRONG>curses</STRONG> set the <STRONG>cbreak</STRONG> mode.
114 Note that <STRONG>cbreak</STRONG> overrides <STRONG>raw</STRONG>. [See <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> for a discussion
115 of how these routines interact with <STRONG>echo</STRONG> and <STRONG>noecho</STRONG>.]
118 </PRE><H3><a name="h3-echo_noecho">echo/noecho</a></H3><PRE>
119 The <STRONG>echo</STRONG> and <STRONG>noecho</STRONG> routines control whether characters typed by the
120 user are echoed by <STRONG><A HREF="curs_getch.3x.html">getch(3x)</A></STRONG> as they are typed. Echoing by the tty
121 driver is always disabled, but initially <STRONG>getch</STRONG> is in echo mode, so
122 characters typed are echoed. Authors of most interactive programs pre-
123 fer to do their own echoing in a controlled area of the screen, or not
124 to echo at all, so they disable echoing by calling <STRONG>noecho</STRONG>. [See
125 <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG> for a discussion of how these routines interact with
126 <STRONG>cbreak</STRONG> and <STRONG>nocbreak</STRONG>.]
129 </PRE><H3><a name="h3-halfdelay">halfdelay</a></H3><PRE>
130 The <STRONG>halfdelay</STRONG> routine is used for half-delay mode, which is similar to
131 <STRONG>cbreak</STRONG> mode in that characters typed by the user are immediately avail-
132 able to the program. However, after blocking for <EM>tenths</EM> tenths of sec-
133 onds, <STRONG>ERR</STRONG> is returned if nothing has been typed. The value of <EM>tenths</EM>
134 must be a number between 1 and 255. Use <STRONG>nocbreak</STRONG> to leave half-delay
138 </PRE><H3><a name="h3-intrflush">intrflush</a></H3><PRE>
139 If the <STRONG>intrflush</STRONG> option is enabled (<EM>bf</EM> is <STRONG>TRUE</STRONG>), and an interrupt key
140 is pressed on the keyboard (interrupt, break, quit), all output in the
141 tty driver queue will be flushed, giving the effect of faster response
142 to the interrupt, but causing <STRONG>curses</STRONG> to have the wrong idea of what is
143 on the screen. Disabling the option (<EM>bf</EM> is <STRONG>FALSE</STRONG>) prevents the flush.
144 The default for the option is inherited from the tty driver settings.
145 The window argument is ignored.
148 </PRE><H3><a name="h3-keypad">keypad</a></H3><PRE>
149 The <STRONG>keypad</STRONG> option enables the keypad of the user's terminal. If en-
150 abled (<EM>bf</EM> is <STRONG>TRUE</STRONG>), the user can press a function key (such as an arrow
151 key) and <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> returns a single value representing the function
152 key, as in <STRONG>KEY_LEFT</STRONG>. If disabled (<EM>bf</EM> is <STRONG>FALSE</STRONG>), <STRONG>curses</STRONG> does not treat
153 function keys specially and the program has to interpret the escape se-
154 quences itself. If the keypad in the terminal can be turned on (made
155 to transmit) and off (made to work locally), turning on this option
156 causes the terminal keypad to be turned on when <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> is called.
157 The default value for keypad is <STRONG>FALSE</STRONG>.
160 </PRE><H3><a name="h3-meta">meta</a></H3><PRE>
161 Initially, whether the terminal returns 7 or 8 significant bits on in-
162 put depends on the control mode of the tty driver [see <STRONG>termios(3)</STRONG>]. To
163 force 8 bits to be returned, invoke <STRONG>meta</STRONG>(<EM>win</EM>, <STRONG>TRUE</STRONG>); this is equiva-
164 lent, under POSIX, to setting the CS8 flag on the terminal. To force 7
165 bits to be returned, invoke <STRONG>meta</STRONG>(<EM>win</EM>, <STRONG>FALSE</STRONG>); this is equivalent, under
166 POSIX, to setting the CS7 flag on the terminal. The window argument,
167 <EM>win</EM>, is always ignored. If the terminfo capabilities <STRONG>smm</STRONG> (meta_on) and
168 <STRONG>rmm</STRONG> (meta_off) are defined for the terminal, <STRONG>smm</STRONG> is sent to the termi-
169 nal when <STRONG>meta</STRONG>(<EM>win</EM>, <STRONG>TRUE</STRONG>) is called and <STRONG>rmm</STRONG> is sent when <STRONG>meta</STRONG>(<EM>win</EM>,
170 <STRONG>FALSE</STRONG>) is called.
173 </PRE><H3><a name="h3-nl_nonl">nl/nonl</a></H3><PRE>
174 The <STRONG>nl</STRONG> and <STRONG>nonl</STRONG> routines control whether the underlying display device
175 translates the return key into newline on input.
178 </PRE><H3><a name="h3-nodelay">nodelay</a></H3><PRE>
179 The <STRONG>nodelay</STRONG> option causes <STRONG>getch</STRONG> to be a non-blocking call. If no input
180 is ready, <STRONG>getch</STRONG> returns <STRONG>ERR</STRONG>. If disabled (<EM>bf</EM> is <STRONG>FALSE</STRONG>), <STRONG>getch</STRONG> waits
181 until a key is pressed.
184 </PRE><H3><a name="h3-notimeout">notimeout</a></H3><PRE>
185 When interpreting an escape sequence, <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG> sets a timer while
186 waiting for the next character. If <STRONG>notimeout(</STRONG><EM>win</EM>, <STRONG>TRUE</STRONG>) is called,
187 then <STRONG>wgetch</STRONG> does not set a timer. The purpose of the timeout is to
188 differentiate between sequences received from a function key and those
192 </PRE><H3><a name="h3-raw_noraw">raw/noraw</a></H3><PRE>
193 The <STRONG>raw</STRONG> and <STRONG>noraw</STRONG> routines place the terminal into or out of raw mode.
194 Raw mode is similar to <STRONG>cbreak</STRONG> mode, in that characters typed are imme-
195 diately passed through to the user program. The differences are that
196 in raw mode, the interrupt, quit, suspend, and flow control characters
197 are all passed through uninterpreted, instead of generating a signal.
198 The behavior of the BREAK key depends on other bits in the tty driver
199 that are not set by <STRONG>curses</STRONG>.
202 </PRE><H3><a name="h3-qiflush_noqiflush">qiflush/noqiflush</a></H3><PRE>
203 When the <STRONG>noqiflush</STRONG> routine is used, normal flush of input and output
204 queues associated with the <STRONG>INTR</STRONG>, <STRONG>QUIT</STRONG> and <STRONG>SUSP</STRONG> characters will not be
205 done [see <STRONG>termios(3)</STRONG>]. When <STRONG>qiflush</STRONG> is called, the queues will be
206 flushed when these control characters are read. You may want to call
207 <STRONG>noqiflush</STRONG> in a signal handler if you want output to continue as though
208 the interrupt had not occurred, after the handler exits.
211 </PRE><H3><a name="h3-timeout_wtimeout">timeout/wtimeout</a></H3><PRE>
212 The <STRONG>timeout</STRONG> and <STRONG>wtimeout</STRONG> routines set blocking or non-blocking read for
213 a given window. If <EM>delay</EM> is negative, blocking read is used (i.e.,
214 waits indefinitely for input). If <EM>delay</EM> is zero, then non-blocking
215 read is used (i.e., read returns <STRONG>ERR</STRONG> if no input is waiting). If <EM>delay</EM>
216 is positive, then read blocks for <EM>delay</EM> milliseconds, and returns <STRONG>ERR</STRONG>
217 if there is still no input. Hence, these routines provide the same
218 functionality as <STRONG>nodelay</STRONG>, plus the additional capability of being able
219 to block for only <EM>delay</EM> milliseconds (where <EM>delay</EM> is positive).
222 </PRE><H3><a name="h3-typeahead">typeahead</a></H3><PRE>
223 The <STRONG>curses</STRONG> library does "line-breakout optimization" by looking for ty-
224 peahead periodically while updating the screen. If input is found, and
225 it is coming from a tty, the current update is postponed until <STRONG>re-</STRONG>
226 <STRONG><A HREF="refresh.3x.html">fresh(3x)</A></STRONG> or <STRONG>doupdate</STRONG> is called again. This allows faster response to
227 commands typed in advance. Normally, the input FILE pointer passed to
228 <STRONG>newterm</STRONG>, or <STRONG>stdin</STRONG> in the case that <STRONG>initscr</STRONG> was used, will be used to do
229 this typeahead checking. The <STRONG>typeahead</STRONG> routine specifies that the file
230 descriptor <EM>fd</EM> is to be used to check for typeahead instead. If <EM>fd</EM> is
231 -1, then no typeahead checking is done.
234 </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
235 All routines that return an integer return <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG>
236 (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>") upon successful
237 completion, unless otherwise noted in the preceding routine descrip-
240 X/Open does not define any error conditions. In this implementation,
241 functions with a window parameter will return an error if it is null.
242 Any function will also return an error if the terminal was not initial-
245 <STRONG>halfdelay</STRONG>
246 returns an error if its parameter is outside the range 1..255.
249 </PRE><H2><a name="h2-EXTENSIONS">EXTENSIONS</a></H2><PRE>
250 This implementation provides four functions which may be used to detect
251 if the corresponding flags were set or reset:
253 <STRONG>Query</STRONG> <STRONG>Set</STRONG> <STRONG>Reset</STRONG>
254 ----------------------------------
255 is_cbreak cbreak nocbreak
260 In each case, the function returns
262 1 if the flag is set,
264 0 if the flag is reset, or
266 -1 if the curses library was not initialized.
268 These routines are specific to ncurses. They were not supported on
269 Version 7, BSD or System V implementations. It is recommended that any
270 code depending on ncurses extensions be conditioned using NCURSES_VER-
274 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
275 Except as noted in the section on extensions, these functions are de-
276 scribed in the XSI Curses standard, Issue 4.
278 The ncurses library obeys the XPG4 standard and the historical practice
279 of the AT&T curses implementations, in that the echo bit is cleared
280 when curses initializes the terminal state. BSD curses differed from
281 this slightly; it left the echo bit on at initialization, but the BSD
282 <STRONG>raw</STRONG> call turned it off as a side-effect. For best portability, set
283 <STRONG>echo</STRONG> or <STRONG>noecho</STRONG> explicitly just after initialization, even if your pro-
284 gram remains in cooked mode.
286 The XSI Curses standard is ambiguous on the question of whether <STRONG>raw</STRONG>
287 should disable the CRLF translations controlled by <STRONG>nl</STRONG> and <STRONG>nonl</STRONG>. BSD
288 curses did turn off these translations; AT&T curses (at least as late
289 as SVr1) did not. We chose to do so, on the theory that a programmer
290 requesting raw input wants a clean (ideally 8-bit clean) connection
291 that the operating system will not alter.
293 When <STRONG>keypad</STRONG> is first enabled, ncurses loads the key-definitions for the
294 current terminal description. If the terminal description includes ex-
295 tended string capabilities, e.g., from using the <STRONG>-x</STRONG> option of <STRONG>tic</STRONG>, then
296 ncurses also defines keys for the capabilities whose names begin with
297 "k". The corresponding keycodes are generated and (depending on previ-
298 ous loads of terminal descriptions) may differ from one execution of a
299 program to the next. The generated keycodes are recognized by the <STRONG>key-</STRONG>
300 <STRONG>name</STRONG> function (which will then return a name beginning with "k" denot-
301 ing the terminfo capability name rather than "K", used for curses key-
302 names). On the other hand, an application can use <STRONG>define_key</STRONG> to estab-
303 lish a specific keycode for a given string. This makes it possible for
304 an application to check for an extended capability's presence with
305 <STRONG>tigetstr</STRONG>, and reassign the keycode to match its own needs.
307 Low-level applications can use <STRONG>tigetstr</STRONG> to obtain the definition of any
308 particular string capability. Higher-level applications which use the
309 curses <STRONG>wgetch</STRONG> and similar functions to return keycodes rely upon the
310 order in which the strings are loaded. If more than one key definition
311 has the same string value, then <STRONG>wgetch</STRONG> can return only one keycode.
312 Most curses implementations (including ncurses) load key definitions in
313 the order defined by the array of string capability names. The last
314 key to be loaded determines the keycode which will be returned. In
315 ncurses, you may also have extended capabilities interpreted as key
316 definitions. These are loaded after the predefined keys, and if a ca-
317 pability's value is the same as a previously-loaded key definition, the
318 later definition is the one used.
321 </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
322 Note that <STRONG>echo</STRONG>, <STRONG>noecho</STRONG>, <STRONG>halfdelay</STRONG>, <STRONG>intrflush</STRONG>, <STRONG>meta</STRONG>, <STRONG>nl</STRONG>, <STRONG>nonl</STRONG>, <STRONG>nodelay</STRONG>,
323 <STRONG>notimeout</STRONG>, <STRONG>noqiflush</STRONG>, <STRONG>qiflush</STRONG>, <STRONG>timeout</STRONG>, and <STRONG>wtimeout</STRONG> may be macros.
325 The <STRONG>noraw</STRONG> and <STRONG>nocbreak</STRONG> calls follow historical practice in that they
326 attempt to restore to normal ("cooked") mode from raw and cbreak modes
327 respectively. Mixing raw/noraw and cbreak/nocbreak calls leads to tty
328 driver control states that are hard to predict or understand; it is not
332 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
333 <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_getch.3x.html">curs_getch(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_util.3x.html">curs_util(3x)</A></STRONG>, <STRONG>de-</STRONG>
334 <STRONG><A HREF="define_key.3x.html">fine_key(3x)</A></STRONG>, <STRONG>termios(3)</STRONG>
338 ncurses 6.4 2023-08-12 <STRONG><A HREF="curs_inopts.3x.html">curs_inopts(3x)</A></STRONG>
342 <li><a href="#h2-NAME">NAME</a></li>
343 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
344 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
346 <li><a href="#h3-cbreak_nocbreak">cbreak/nocbreak</a></li>
347 <li><a href="#h3-echo_noecho">echo/noecho</a></li>
348 <li><a href="#h3-halfdelay">halfdelay</a></li>
349 <li><a href="#h3-intrflush">intrflush</a></li>
350 <li><a href="#h3-keypad">keypad</a></li>
351 <li><a href="#h3-meta">meta</a></li>
352 <li><a href="#h3-nl_nonl">nl/nonl</a></li>
353 <li><a href="#h3-nodelay">nodelay</a></li>
354 <li><a href="#h3-notimeout">notimeout</a></li>
355 <li><a href="#h3-raw_noraw">raw/noraw</a></li>
356 <li><a href="#h3-qiflush_noqiflush">qiflush/noqiflush</a></li>
357 <li><a href="#h3-timeout_wtimeout">timeout/wtimeout</a></li>
358 <li><a href="#h3-typeahead">typeahead</a></li>
361 <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
362 <li><a href="#h2-EXTENSIONS">EXTENSIONS</a></li>
363 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
364 <li><a href="#h2-NOTES">NOTES</a></li>
365 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>