1STTY(1P) POSIX Programmer's Manual STTY(1P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 stty — set the options for a terminal
13
15 stty [-a|-g]
16 stty operand...
18
20 The stty utility shall set or report on terminal I/O characteristics
21 for the device that is its standard input. Without options or operands
22 specified, it shall report the settings of certain characteristics,
23 usually those that differ from implementation-defined defaults. Other‐
24 wise, it shall modify the terminal state according to the specified op‐
25 erands. Detailed information about the modes listed in the first five
26 groups below are described in the Base Definitions volume of
27 POSIX.1‐2017, Chapter 11, General Terminal Interface. Operands in the
28 Combination Modes group (see Combination Modes) are implemented using
29 operands in the previous groups. Some combinations of operands are
30 mutually-exclusive on some terminal types; the results of using such
31 combinations are unspecified.
32 Typical implementations of this utility require a communications line
34 configured to use the termios interface defined in the System Inter‐
35 faces volume of POSIX.1‐2017. On systems where none of these lines are
36 available, and on lines not currently configured to support the termios
37 interface, some of the operands need not affect terminal characteris‐
38 tics.
39
41 The stty utility shall conform to the Base Definitions volume of
42 POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines.
43 The following options shall be supported:
45 -a Write to standard output all the current settings for the
47 terminal.
48 -g Write to standard output all the current settings in an
50 unspecified form that can be used as arguments to another
51 invocation of the stty utility on the same system. The form
52 used shall not contain any characters that would require
53 quoting to avoid word expansion by the shell; see Section
54 2.6, Word Expansions.
55
57 The following operands shall be supported to set the terminal charac‐
58 teristics.
59 Control Modes
61 parenb (-parenb)
62 Enable (disable) parity generation and detection. This
63 shall have the effect of setting (not setting) PARENB in
64 the termios c_cflag field, as defined in the Base Defini‐
65 tions volume of POSIX.1‐2017, Chapter 11, General Terminal
66 Interface.
67 parodd (-parodd)
69 Select odd (even) parity. This shall have the effect of
70 setting (not setting) PARODD in the termios c_cflag field,
71 as defined in the Base Definitions volume of POSIX.1‐2017,
72 Chapter 11, General Terminal Interface.
73 cs5 cs6 cs7 cs8
75 Select character size, if possible. This shall have the
76 effect of setting CS5, CS6, CS7, and CS8, respectively, in
77 the termios c_cflag field, as defined in the Base Defini‐
78 tions volume of POSIX.1‐2017, Chapter 11, General Terminal
79 Interface.
80 number Set terminal baud rate to the number given, if possible. If
82 the baud rate is set to zero, the modem control lines shall
83 no longer be asserted. This shall have the effect of set‐
84 ting the input and output termios baud rate values as
85 defined in the Base Definitions volume of POSIX.1‐2017,
86 Chapter 11, General Terminal Interface.
87 ispeed number
89 Set terminal input baud rate to the number given, if possi‐
90 ble. If the input baud rate is set to zero, the input baud
91 rate shall be specified by the value of the output baud
92 rate. This shall have the effect of setting the input
93 termios baud rate values as defined in the Base Definitions
94 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
95 face.
96 ospeed number
98 Set terminal output baud rate to the number given, if pos‐
99 sible. If the output baud rate is set to zero, the modem
100 control lines shall no longer be asserted. This shall have
101 the effect of setting the output termios baud rate values
102 as defined in the Base Definitions volume of POSIX.1‐2017,
103 Chapter 11, General Terminal Interface.
104 hupcl (-hupcl)
106 Stop asserting modem control lines (do not stop asserting
107 modem control lines) on last close. This shall have the
108 effect of setting (not setting) HUPCL in the termios
109 c_cflag field, as defined in the Base Definitions volume of
110 POSIX.1‐2017, Chapter 11, General Terminal Interface.
111 hup (-hup) Equivalent to hupcl(-hupcl).
113 cstopb (-cstopb)
115 Use two (one) stop bits per character. This shall have the
116 effect of setting (not setting) CSTOPB in the termios
117 c_cflag field, as defined in the Base Definitions volume of
118 POSIX.1‐2017, Chapter 11, General Terminal Interface.
119 cread (-cread)
121 Enable (disable) the receiver. This shall have the effect
122 of setting (not setting) CREAD in the termios c_cflag
123 field, as defined in the Base Definitions volume of
124 POSIX.1‐2017, Chapter 11, General Terminal Interface.
125 clocal (-clocal)
127 Assume a line without (with) modem control. This shall have
128 the effect of setting (not setting) CLOCAL in the termios
129 c_cflag field, as defined in the Base Definitions volume of
130 POSIX.1‐2017, Chapter 11, General Terminal Interface.
131 It is unspecified whether stty shall report an error if an attempt to
133 set a Control Mode fails.
134 Input Modes
136 ignbrk (-ignbrk)
137 Ignore (do not ignore) break on input. This shall have the
138 effect of setting (not setting) IGNBRK in the termios
139 c_iflag field, as defined in the Base Definitions volume of
140 POSIX.1‐2017, Chapter 11, General Terminal Interface.
141 brkint (-brkint)
143 Signal (do not signal) INTR on break. This shall have the
144 effect of setting (not setting) BRKINT in the termios
145 c_iflag field, as defined in the Base Definitions volume of
146 POSIX.1‐2017, Chapter 11, General Terminal Interface.
147 ignpar (-ignpar)
149 Ignore (do not ignore) bytes with parity errors. This shall
150 have the effect of setting (not setting) IGNPAR in the
151 termios c_iflag field, as defined in the Base Definitions
152 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
153 face.
154 parmrk (-parmrk)
156 Mark (do not mark) parity errors. This shall have the
157 effect of setting (not setting) PARMRK in the termios
158 c_iflag field, as defined in the Base Definitions volume of
159 POSIX.1‐2017, Chapter 11, General Terminal Interface.
160 inpck (-inpck)
162 Enable (disable) input parity checking. This shall have the
163 effect of setting (not setting) INPCK in the termios
164 c_iflag field, as defined in the Base Definitions volume of
165 POSIX.1‐2017, Chapter 11, General Terminal Interface.
166 istrip (-istrip)
168 Strip (do not strip) input characters to seven bits. This
169 shall have the effect of setting (not setting) ISTRIP in
170 the termios c_iflag field, as defined in the Base Defini‐
171 tions volume of POSIX.1‐2017, Chapter 11, General Terminal
172 Interface.
173 inlcr (-inlcr)
175 Map (do not map) NL to CR on input. This shall have the
176 effect of setting (not setting) INLCR in the termios
177 c_iflag field, as defined in the Base Definitions volume of
178 POSIX.1‐2017, Chapter 11, General Terminal Interface.
179 igncr (-igncr)
181 Ignore (do not ignore) CR on input. This shall have the
182 effect of setting (not setting) IGNCR in the termios
183 c_iflag field, as defined in the Base Definitions volume of
184 POSIX.1‐2017, Chapter 11, General Terminal Interface.
185 icrnl (-icrnl)
187 Map (do not map) CR to NL on input. This shall have the
188 effect of setting (not setting) ICRNL in the termios
189 c_iflag field, as defined in the Base Definitions volume of
190 POSIX.1‐2017, Chapter 11, General Terminal Interface.
191 ixon (-ixon)
193 Enable (disable) START/STOP output control. Output from the
194 system is stopped when the system receives STOP and started
195 when the system receives START. This shall have the effect
196 of setting (not setting) IXON in the termios c_iflag field,
197 as defined in the Base Definitions volume of POSIX.1‐2017,
198 Chapter 11, General Terminal Interface.
199 ixany (-ixany)
201 Allow any character to restart output. This shall have the
202 effect of setting (not setting) IXANY in the termios
203 c_iflag field, as defined in the Base Definitions volume of
204 POSIX.1‐2017, Chapter 11, General Terminal Interface.
205 ixoff (-ixoff)
207 Request that the system send (not send) STOP characters
208 when the input queue is nearly full and START characters to
209 resume data transmission. This shall have the effect of
210 setting (not setting) IXOFF in the termios c_iflag field,
211 as defined in the Base Definitions volume of POSIX.1‐2017,
212 Chapter 11, General Terminal Interface.
213 Output Modes
215 opost (-opost)
216 Post-process output (do not post-process output; ignore all
217 other output modes). This shall have the effect of setting
218 (not setting) OPOST in the termios c_oflag field, as
219 defined in the Base Definitions volume of POSIX.1‐2017,
220 Chapter 11, General Terminal Interface.
221 onlcr (-onlcr)
223 Map (do not map) NL to CR-NL on output. This shall have the
224 effect of setting (not setting) ONLCR in the termios
225 c_oflag field, as defined in the Base Definitions volume of
226 POSIX.1‐2017, Chapter 11, General Terminal Interface.
227 ocrnl (-ocrnl)
229 Map (do not map) CR to NL on output. This shall have the
230 effect of setting (not setting) OCRNL in the termios
231 c_oflag field, as defined in the Base Definitions volume of
232 POSIX.1‐2017, Chapter 11, General Terminal Interface.
233 onocr (-onocr)
235 Do not (do) output CR at column zero. This shall have the
236 effect of setting (not setting) ONOCR in the termios
237 c_oflag field, as defined in the Base Definitions volume of
238 POSIX.1‐2017, Chapter 11, General Terminal Interface.
239 onlret (-onlret)
241 The terminal newline key performs (does not perform) the CR
242 function. This shall have the effect of setting (not set‐
243 ting) ONLRET in the termios c_oflag field, as defined in
244 the Base Definitions volume of POSIX.1‐2017, Chapter 11,
245 General Terminal Interface.
246 ofill (-ofill)
248 Use fill characters (use timing) for delays. This shall
249 have the effect of setting (not setting) OFILL in the
250 termios c_oflag field, as defined in the Base Definitions
251 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
252 face.
253 ofdel (-ofdel)
255 Fill characters are DELs (NULs). This shall have the effect
256 of setting (not setting) OFDEL in the termios c_oflag
257 field, as defined in the Base Definitions volume of
258 POSIX.1‐2017, Chapter 11, General Terminal Interface.
259 cr0 cr1 cr2 cr3
261 Select the style of delay for CRs. This shall have the
262 effect of setting CRDLY to CR0, CR1, CR2, or CR3, respec‐
263 tively, in the termios c_oflag field, as defined in the
264 Base Definitions volume of POSIX.1‐2017, Chapter 11, Gen‐
265 eral Terminal Interface.
266 nl0 nl1 Select the style of delay for NL. This shall have the
268 effect of setting NLDLY to NL0 or NL1, respectively, in the
269 termios c_oflag field, as defined in the Base Definitions
270 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
271 face.
272 tab0 tab1 tab2 tab3
274 Select the style of delay for horizontal tabs. This shall
275 have the effect of setting TABDLY to TAB0, TAB1, TAB2, or
276 TAB3, respectively, in the termios c_oflag field, as
277 defined in the Base Definitions volume of POSIX.1‐2017,
278 Chapter 11, General Terminal Interface. Note that TAB3 has
279 the effect of expanding <tab> characters to <space> charac‐
280 ters.
281 tabs (-tabs)
283 Synonym for tab0 (tab3).
284 bs0 bs1 Select the style of delay for <backspace> characters. This
286 shall have the effect of setting BSDLY to BS0 or BS1,
287 respectively, in the termios c_oflag field, as defined in
288 the Base Definitions volume of POSIX.1‐2017, Chapter 11,
289 General Terminal Interface.
290 ff0 ff1 Select the style of delay for <form-feed> characters. This
292 shall have the effect of setting FFDLY to FF0 or FF1,
293 respectively, in the termios c_oflag field, as defined in
294 the Base Definitions volume of POSIX.1‐2017, Chapter 11,
295 General Terminal Interface.
296 vt0 vt1 Select the style of delay for <vertical-tab> characters.
298 This shall have the effect of setting VTDLY to VT0 or VT1,
299 respectively, in the termios c_oflag field, as defined in
300 the Base Definitions volume of POSIX.1‐2017, Chapter 11,
301 General Terminal Interface.
302 Local Modes
304 isig (-isig)
305 Enable (disable) the checking of characters against the
306 special control characters INTR, QUIT, and SUSP. This shall
307 have the effect of setting (not setting) ISIG in the
308 termios c_lflag field, as defined in the Base Definitions
309 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
310 face.
311 icanon (-icanon)
313 Enable (disable) canonical input (ERASE and KILL process‐
314 ing). This shall have the effect of setting (not setting)
315 ICANON in the termios c_lflag field, as defined in the Base
316 Definitions volume of POSIX.1‐2017, Chapter 11, General
317 Terminal Interface.
318 iexten (-iexten)
320 Enable (disable) any implementation-defined special control
321 characters not currently controlled by icanon, isig, ixon,
322 or ixoff. This shall have the effect of setting (not set‐
323 ting) IEXTEN in the termios c_lflag field, as defined in
324 the Base Definitions volume of POSIX.1‐2017, Chapter 11,
325 General Terminal Interface.
326 echo (-echo)
328 Echo back (do not echo back) every character typed. This
329 shall have the effect of setting (not setting) ECHO in the
330 termios c_lflag field, as defined in the Base Definitions
331 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
332 face.
333 echoe (-echoe)
335 The ERASE character visually erases (does not erase) the
336 last character in the current line from the display, if
337 possible. This shall have the effect of setting (not set‐
338 ting) ECHOE in the termios c_lflag field, as defined in the
339 Base Definitions volume of POSIX.1‐2017, Chapter 11, Gen‐
340 eral Terminal Interface.
341 echok (-echok)
343 Echo (do not echo) NL after KILL character. This shall have
344 the effect of setting (not setting) ECHOK in the termios
345 c_lflag field, as defined in the Base Definitions volume of
346 POSIX.1‐2017, Chapter 11, General Terminal Interface.
347 echonl (-echonl)
349 Echo (do not echo) NL, even if echo is disabled. This shall
350 have the effect of setting (not setting) ECHONL in the
351 termios c_lflag field, as defined in the Base Definitions
352 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
353 face.
354 noflsh (-noflsh)
356 Disable (enable) flush after INTR, QUIT, SUSP. This shall
357 have the effect of setting (not setting) NOFLSH in the
358 termios c_lflag field, as defined in the Base Definitions
359 volume of POSIX.1‐2017, Chapter 11, General Terminal Inter‐
360 face.
361 tostop (-tostop)
363 Send SIGTTOU for background output. This shall have the
364 effect of setting (not setting) TOSTOP in the termios
365 c_lflag field, as defined in the Base Definitions volume of
366 POSIX.1‐2017, Chapter 11, General Terminal Interface.
367 Special Control Character Assignments
369 <control>‐character string
370 Set <control>‐character to string. If <control>‐character is one
371 of the character sequences in the first column of the following
372 table, the corresponding the Base Definitions volume of
373 POSIX.1‐2017, Chapter 11, General Terminal Interface control
374 character from the second column shall be recognized. This has
375 the effect of setting the corresponding element of the termios
376 c_cc array (see the Base Definitions volume of POSIX.1‐2017,
377 Chapter 13, Headers, <termios.h>).
378 Table: Control Character Names in stty
380 ┌──────────────────┬────────────────┬─────────────────┐
382 │Control Character │ c_cc Subscript │ Description │
383 ├──────────────────┼────────────────┼─────────────────┤
384 │eof │ VEOF │ EOF character │
385 │eol │ VEOL │ EOL character │
386 │erase │ VERASE │ ERASE character │
387 │intr │ VINTR │ INTR character │
388 │kill │ VKILL │ KILL character │
389 │quit │ VQUIT │ QUIT character │
390 │susp │ VSUSP │ SUSP character │
391 │start │ VSTART │ START character │
392 │stop │ VSTOP │ STOP character │
393 └──────────────────┴────────────────┴─────────────────┘
394 If string is a single character, the control character shall be
395 set to that character. If string is the two-character sequence
396 "^-" or the string undef, the control character shall be set to
397 _POSIX_VDISABLE , if it is in effect for the device; if
398 _POSIX_VDISABLE is not in effect for the device, it shall be
399 treated as an error. In the POSIX locale, if string is a two-
400 character sequence beginning with <circumflex> ('^'), and the
401 second character is one of those listed in the "^c" column of the
402 following table, the control character shall be set to the corre‐
403 sponding character value in the Value column of the table.
404 Table: Circumflex Control Characters in stty
406 ┌──────────────┬────────────────┬──────────────┐
408 │ ^c Value │ ^c Value │ ^c Value │
409 ├──────────────┼────────────────┼──────────────┤
410 │a, A <SOH> │ l, L <FF> │ w, W <ETB> │
411 │b, B <STX> │ m, M <CR> │ x, X <CAN> │
412 │c, C <ETX> │ n, N <SO> │ y, Y <EM> │
413 │d, D <EOT> │ o, O <SI> │ z, Z <SUB> │
414 │e, E <ENQ> │ p, P <DLE> │ [ <ESC> │
415 │f, F <ACK> │ q, Q <DC1> │ \ <FS> │
416 │g, G <BEL> │ r, R <DC2> │ ] <GS> │
417 │h, H <BS> │ s, S <DC3> │ ^ <RS> │
418 │i, I <HT> │ t, T <DC4> │ _ <US> │
419 │j, J <LF> │ u, U <NAK> │ ? <DEL> │
420 │k, K <VT> │ v, V <SYN> │ │
421 └──────────────┴────────────────┴──────────────┘
422 min number
423 Set the value of MIN to number. MIN is used in non-canonical
424 mode input processing (icanon).
425 time number
427 Set the value of TIME to number. TIME is used in non-canonical
428 mode input processing (icanon).
429 Combination Modes
431 saved settings
432 Set the current terminal characteristics to the saved settings
433 produced by the -g option.
434 evenp or parity
436 Enable parenb and cs7; disable parodd.
437 oddp
439 Enable parenb, cs7, and parodd.
440 -parity, -evenp, or -oddp
442 Disable parenb, and set cs8.
443 raw (-raw or cooked)
445 Enable (disable) raw input and output. Raw mode shall be equiva‐
446 lent to setting:
447 stty cs8 erase ^- kill ^- intr ^- \
450 quit ^- eof ^- eol ^- -post -inpck
451 nl (-nl)
453 Disable (enable) icrnl. In addition, -nl unsets inlcr and igncr.
454 ek Reset ERASE and KILL characters back to system defaults.
456 sane
458 Reset all modes to some reasonable, unspecified, values.
459
461 Although no input is read from standard input, standard input shall be
462 used to get the current terminal I/O characteristics and to set new
463 terminal I/O characteristics.
464
466 None.
467
469 The following environment variables shall affect the execution of stty:
470 LANG Provide a default value for the internationalization vari‐
472 ables that are unset or null. (See the Base Definitions vol‐
473 ume of POSIX.1‐2017, Section 8.2, Internationalization Vari‐
474 ables for the precedence of internationalization variables
475 used to determine the values of locale categories.)
476 LC_ALL If set to a non-empty string value, override the values of
478 all the other internationalization variables.
479 LC_CTYPE This variable determines the locale for the interpretation of
481 sequences of bytes of text data as characters (for example,
482 single-byte as opposed to multi-byte characters in arguments)
483 and which characters are in the class print.
484 LC_MESSAGES
486 Determine the locale that should be used to affect the format
487 and contents of diagnostic messages written to standard
488 error.
489 NLSPATH Determine the location of message catalogs for the processing
491 of LC_MESSAGES.
492
494 Default.
495
497 If operands are specified, no output shall be produced.
498 If the -g option is specified, stty shall write to standard output the
500 current settings in a form that can be used as arguments to another
501 instance of stty on the same system.
502 If the -a option is specified, all of the information as described in
504 the OPERANDS section shall be written to standard output. Unless other‐
505 wise specified, this information shall be written as <space>-separated
506 tokens in an unspecified format, on one or more lines, with an unspeci‐
507 fied number of tokens per line. Additional information may be written.
508 If no options or operands are specified, an unspecified subset of the
510 information written for the -a option shall be written.
511 If speed information is written as part of the default output, or if
513 the -a option is specified and if the terminal input speed and output
514 speed are the same, the speed information shall be written as follows:
515 "speed %d baud;", <speed>
518 Otherwise, speeds shall be written as:
520 "ispeed %d baud; ospeed %d baud;", <ispeed>, <ospeed>
523 In locales other than the POSIX locale, the word baud may be changed to
525 something more appropriate in those locales.
526 If control characters are written as part of the default output, or if
528 the -a option is specified, control characters shall be written as:
529 "%s = %s;", <control-character name>, <value>
532 where <value> is either the character, or some visual representation of
534 the character if it is non-printable, or the string undef if the char‐
535 acter is disabled.
536
538 The standard error shall be used only for diagnostic messages.
539
541 None.
542
544 None.
545
547 The following exit values shall be returned:
548 0 The terminal options were read or set successfully.
550 >0 An error occurred.
552
554 Default.
555 The following sections are informative.
557
559 The -g flag is designed to facilitate the saving and restoring of ter‐
560 minal state from the shell level. For example, a program may:
561 saveterm="$(stty -g)" # save terminal state
564 stty (new settings) # set new state
565 ... # ...
566 stty $saveterm # restore terminal state
567 Since the format is unspecified, the saved value is not portable across
569 systems.
570 Since the -a format is so loosely specified, scripts that save and
572 restore terminal settings should use the -g option.
573
575 None.
576
578 The original stty description was taken directly from System V and
579 reflected the System V terminal driver termio. It has been modified to
580 correspond to the terminal driver termios.
581 Output modes are specified only for XSI-conformant systems. All imple‐
583 mentations are expected to provide stty operands corresponding to all
584 of the output modes they support.
585 The stty utility is primarily used to tailor the user interface of the
587 terminal, such as selecting the preferred ERASE and KILL characters. As
588 an application programming utility, stty can be used within shell
589 scripts to alter the terminal settings for the duration of the script.
590 The termios section states that individual disabling of control charac‐
592 ters is possible through the option _POSIX_VDISABLE. If enabled, two
593 conventions currently exist for specifying this: System V uses "^-",
594 and BSD uses undef. Both are accepted by stty in this volume of
595 POSIX.1‐2017. The other BSD convention of using the letter 'u' was
596 rejected because it conflicts with the actual letter 'u', which is an
597 acceptable value for a control character.
598 Early proposals did not specify the mapping of "^c" to control charac‐
600 ters because the control characters were not specified in the POSIX
601 locale character set description file requirements. The control charac‐
602 ter set is now specified in the Base Definitions volume of
603 POSIX.1‐2017, Chapter 3, Definitions, so the historical mapping is
604 specified. Note that although the mapping corresponds to control-char‐
605 acter key assignments on many terminals that use the ISO/IEC 646:1991
606 standard (or ASCII) character encodings, the mapping specified here is
607 to the control characters, not their keyboard encodings.
608 Since termios supports separate speeds for input and output, two new
610 options were added to specify each distinctly.
611 Some historical implementations use standard input to get and set ter‐
613 minal characteristics; others use standard output. Since input from a
614 login TTY is usually restricted to the owner while output to a TTY is
615 frequently open to anyone, using standard input provides fewer chances
616 of accidentally (or maliciously) altering the terminal settings of
617 other users. Using standard input also allows stty -a and stty -g out‐
618 put to be redirected for later use. Therefore, usage of standard input
619 is required by this volume of POSIX.1‐2017.
620
622 None.
623
625 Chapter 2, Shell Command Language
626 The Base Definitions volume of POSIX.1‐2017, Chapter 8, Environment
628 Variables, Chapter 11, General Terminal Interface, Section 12.2, Util‐
629 ity Syntax Guidelines, <termios.h>
630
632 Portions of this text are reprinted and reproduced in electronic form
633 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
634 table Operating System Interface (POSIX), The Open Group Base Specifi‐
635 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
636 Electrical and Electronics Engineers, Inc and The Open Group. In the
637 event of any discrepancy between this version and the original IEEE and
638 The Open Group Standard, the original IEEE and The Open Group Standard
639 is the referee document. The original Standard can be obtained online
640 at http://www.opengroup.org/unix/online.html .
641 Any typographical or formatting errors that appear in this page are
643 most likely to have been introduced during the conversion of the source
644 files to man page format. To report such errors, see https://www.ker‐
645 nel.org/doc/man-pages/reporting_bugs.html .
646IEEE/The Open Group 2017 STTY(1P)