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
13 stty — set the options for a terminal
14
16 stty [−a|−g]
17 stty operand...
19
21 The stty utility shall set or report on terminal I/O characteristics
22 for the device that is its standard input. Without options or operands
23 specified, it shall report the settings of certain characteristics,
24 usually those that differ from implementation-defined defaults. Other‐
25 wise, it shall modify the terminal state according to the specified op‐
26 erands. Detailed information about the modes listed in the first five
27 groups below are described in the Base Definitions volume of
28 POSIX.1‐2008, Chapter 11, General Terminal Interface. Operands in the
29 Combination Modes group (see Combination Modes) are implemented using
30 operands in the previous groups. Some combinations of operands are
31 mutually-exclusive on some terminal types; the results of using such
32 combinations are unspecified.
33 Typical implementations of this utility require a communications line
35 configured to use the termios interface defined in the System Inter‐
36 faces volume of POSIX.1‐2008. On systems where none of these lines are
37 available, and on lines not currently configured to support the termios
38 interface, some of the operands need not affect terminal characteris‐
39 tics.
40
42 The stty utility shall conform to the Base Definitions volume of
43 POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines.
44 The following options shall be supported:
46 −a Write to standard output all the current settings for the
48 terminal.
49 −g Write to standard output all the current settings in an
51 unspecified form that can be used as arguments to another
52 invocation of the stty utility on the same system. The form
53 used shall not contain any characters that would require
54 quoting to avoid word expansion by the shell; see Section
55 2.6, Word Expansions.
56
58 The following operands shall be supported to set the terminal charac‐
59 teristics.
60 Control Modes
62 parenb (−parenb)
63 Enable (disable) parity generation and detection. This
64 shall have the effect of setting (not setting) PARENB in
65 the termios c_cflag field, as defined in the Base Defini‐
66 tions volume of POSIX.1‐2008, Chapter 11, General Terminal
67 Interface.
68 parodd (−parodd)
70 Select odd (even) parity. This shall have the effect of
71 setting (not setting) PARODD in the termios c_cflag field,
72 as defined in the Base Definitions volume of POSIX.1‐2008,
73 Chapter 11, General Terminal Interface.
74 cs5 cs6 cs7 cs8
76 Select character size, if possible. This shall have the
77 effect of setting CS5, CS6, CS7, and CS8, respectively, in
78 the termios c_cflag field, as defined in the Base Defini‐
79 tions volume of POSIX.1‐2008, Chapter 11, General Terminal
80 Interface.
81 number Set terminal baud rate to the number given, if possible. If
83 the baud rate is set to zero, the modem control lines shall
84 no longer be asserted. This shall have the effect of set‐
85 ting the input and output termios baud rate values as
86 defined in the Base Definitions volume of POSIX.1‐2008,
87 Chapter 11, General Terminal Interface.
88 ispeed number
90 Set terminal input baud rate to the number given, if possi‐
91 ble. If the input baud rate is set to zero, the input baud
92 rate shall be specified by the value of the output baud
93 rate. This shall have the effect of setting the input
94 termios baud rate values as defined in the Base Definitions
95 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
96 face.
97 ospeed number
99 Set terminal output baud rate to the number given, if pos‐
100 sible. If the output baud rate is set to zero, the modem
101 control lines shall no longer be asserted. This shall have
102 the effect of setting the output termios baud rate values
103 as defined in the Base Definitions volume of POSIX.1‐2008,
104 Chapter 11, General Terminal Interface.
105 hupcl (−hupcl)
107 Stop asserting modem control lines (do not stop asserting
108 modem control lines) on last close. This shall have the
109 effect of setting (not setting) HUPCL in the termios
110 c_cflag field, as defined in the Base Definitions volume of
111 POSIX.1‐2008, Chapter 11, General Terminal Interface.
112 hup (−hup) Equivalent to hupcl(−hupcl).
114 cstopb (−cstopb)
116 Use two (one) stop bits per character. This shall have the
117 effect of setting (not setting) CSTOPB in the termios
118 c_cflag field, as defined in the Base Definitions volume of
119 POSIX.1‐2008, Chapter 11, General Terminal Interface.
120 cread (−cread)
122 Enable (disable) the receiver. This shall have the effect
123 of setting (not setting) CREAD in the termios c_cflag
124 field, as defined in the Base Definitions volume of
125 POSIX.1‐2008, Chapter 11, General Terminal Interface.
126 clocal (−clocal)
128 Assume a line without (with) modem control. This shall have
129 the effect of setting (not setting) CLOCAL in the termios
130 c_cflag field, as defined in the Base Definitions volume of
131 POSIX.1‐2008, Chapter 11, General Terminal Interface.
132 It is unspecified whether stty shall report an error if an attempt to
134 set a Control Mode fails.
135 Input Modes
137 ignbrk (−ignbrk)
138 Ignore (do not ignore) break on input. This shall have the
139 effect of setting (not setting) IGNBRK in the termios
140 c_iflag field, as defined in the Base Definitions volume of
141 POSIX.1‐2008, Chapter 11, General Terminal Interface.
142 brkint (−brkint)
144 Signal (do not signal) INTR on break. This shall have the
145 effect of setting (not setting) BRKINT in the termios
146 c_iflag field, as defined in the Base Definitions volume of
147 POSIX.1‐2008, Chapter 11, General Terminal Interface.
148 ignpar (−ignpar)
150 Ignore (do not ignore) bytes with parity errors. This shall
151 have the effect of setting (not setting) IGNPAR in the
152 termios c_iflag field, as defined in the Base Definitions
153 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
154 face.
155 parmrk (−parmrk)
157 Mark (do not mark) parity errors. This shall have the
158 effect of setting (not setting) PARMRK in the termios
159 c_iflag field, as defined in the Base Definitions volume of
160 POSIX.1‐2008, Chapter 11, General Terminal Interface.
161 inpck (−inpck)
163 Enable (disable) input parity checking. This shall have the
164 effect of setting (not setting) INPCK in the termios
165 c_iflag field, as defined in the Base Definitions volume of
166 POSIX.1‐2008, Chapter 11, General Terminal Interface.
167 istrip (−istrip)
169 Strip (do not strip) input characters to seven bits. This
170 shall have the effect of setting (not setting) ISTRIP in
171 the termios c_iflag field, as defined in the Base Defini‐
172 tions volume of POSIX.1‐2008, Chapter 11, General Terminal
173 Interface.
174 inlcr (−inlcr)
176 Map (do not map) NL to CR on input. This shall have the
177 effect of setting (not setting) INLCR in the termios
178 c_iflag field, as defined in the Base Definitions volume of
179 POSIX.1‐2008, Chapter 11, General Terminal Interface.
180 igncr (−igncr)
182 Ignore (do not ignore) CR on input. This shall have the
183 effect of setting (not setting) IGNCR in the termios
184 c_iflag field, as defined in the Base Definitions volume of
185 POSIX.1‐2008, Chapter 11, General Terminal Interface.
186 icrnl (−icrnl)
188 Map (do not map) CR to NL on input. This shall have the
189 effect of setting (not setting) ICRNL in the termios
190 c_iflag field, as defined in the Base Definitions volume of
191 POSIX.1‐2008, Chapter 11, General Terminal Interface.
192 ixon (−ixon)
194 Enable (disable) START/STOP output control. Output from the
195 system is stopped when the system receives STOP and started
196 when the system receives START. This shall have the effect
197 of setting (not setting) IXON in the termios c_iflag field,
198 as defined in the Base Definitions volume of POSIX.1‐2008,
199 Chapter 11, General Terminal Interface.
200 ixany (−ixany)
202 Allow any character to restart output. This shall have the
203 effect of setting (not setting) IXANY in the termios
204 c_iflag field, as defined in the Base Definitions volume of
205 POSIX.1‐2008, Chapter 11, General Terminal Interface.
206 ixoff (−ixoff)
208 Request that the system send (not send) STOP characters
209 when the input queue is nearly full and START characters to
210 resume data transmission. This shall have the effect of
211 setting (not setting) IXOFF in the termios c_iflag field,
212 as defined in the Base Definitions volume of POSIX.1‐2008,
213 Chapter 11, General Terminal Interface.
214 Output Modes
216 opost (−opost)
217 Post-process output (do not post-process output; ignore all
218 other output modes). This shall have the effect of setting
219 (not setting) OPOST in the termios c_oflag field, as
220 defined in the Base Definitions volume of POSIX.1‐2008,
221 Chapter 11, General Terminal Interface.
222 ocrnl (−ocrnl)
224 Map (do not map) CR to NL on output This shall have the
225 effect of setting (not setting) OCRNL in the termios
226 c_oflag field, as defined in the Base Definitions volume of
227 POSIX.1‐2008, Chapter 11, General Terminal Interface.
228 onocr (−onocr)
230 Do not (do) output CR at column zero. This shall have the
231 effect of setting (not setting) ONOCR in the termios
232 c_oflag field, as defined in the Base Definitions volume of
233 POSIX.1‐2008, Chapter 11, General Terminal Interface.
234 onlret (−onlret)
236 The terminal newline key performs (does not perform) the CR
237 function. This shall have the effect of setting (not set‐
238 ting) ONLRET in the termios c_oflag field, as defined in
239 the Base Definitions volume of POSIX.1‐2008, Chapter 11,
240 General Terminal Interface.
241 ofill (−ofill)
243 Use fill characters (use timing) for delays. This shall
244 have the effect of setting (not setting) OFILL in the
245 termios c_oflag field, as defined in the Base Definitions
246 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
247 face.
248 ofdel (−ofdel)
250 Fill characters are DELs (NULs). This shall have the effect
251 of setting (not setting) OFDEL in the termios c_oflag
252 field, as defined in the Base Definitions volume of
253 POSIX.1‐2008, Chapter 11, General Terminal Interface.
254 cr0 cr1 cr2 cr3
256 Select the style of delay for CRs. This shall have the
257 effect of setting CRDLY to CR0, CR1, CR2, or CR3, respec‐
258 tively, in the termios c_oflag field, as defined in the
259 Base Definitions volume of POSIX.1‐2008, Chapter 11, Gen‐
260 eral Terminal Interface.
261 nl0 nl1 Select the style of delay for NL. This shall have the
263 effect of setting NLDLY to NL0 or NL1, respectively, in the
264 termios c_oflag field, as defined in the Base Definitions
265 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
266 face.
267 tab0 tab1 tab2 tab3
269 Select the style of delay for horizontal tabs. This shall
270 have the effect of setting TABDLY to TAB0, TAB1, TAB2, or
271 TAB3, respectively, in the termios c_oflag field, as
272 defined in the Base Definitions volume of POSIX.1‐2008,
273 Chapter 11, General Terminal Interface. Note that TAB3 has
274 the effect of expanding <tab> characters to <space> charac‐
275 ters.
276 tabs (−tabs)
278 Synonym for tab0 (tab3).
279 bs0 bs1 Select the style of delay for <backspace> characters. This
281 shall have the effect of setting BSDLY to BS0 or BS1,
282 respectively, in the termios c_oflag field, as defined in
283 the Base Definitions volume of POSIX.1‐2008, Chapter 11,
284 General Terminal Interface.
285 ff0 ff1 Select the style of delay for <form-feed> characters. This
287 shall have the effect of setting FFDLY to FF0 or FF1,
288 respectively, in the termios c_oflag field, as defined in
289 the Base Definitions volume of POSIX.1‐2008, Chapter 11,
290 General Terminal Interface.
291 vt0 vt1 Select the style of delay for <vertical-tab> characters.
293 This shall have the effect of setting VTDLY to VT0 or VT1,
294 respectively, in the termios c_oflag field, as defined in
295 the Base Definitions volume of POSIX.1‐2008, Chapter 11,
296 General Terminal Interface.
297 Local Modes
299 isig (−isig)
300 Enable (disable) the checking of characters against the
301 special control characters INTR, QUIT, and SUSP. This shall
302 have the effect of setting (not setting) ISIG in the
303 termios c_lflag field, as defined in the Base Definitions
304 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
305 face.
306 icanon (−icanon)
308 Enable (disable) canonical input (ERASE and KILL process‐
309 ing). This shall have the effect of setting (not setting)
310 ICANON in the termios c_lflag field, as defined in the Base
311 Definitions volume of POSIX.1‐2008, Chapter 11, General
312 Terminal Interface.
313 iexten (−iexten)
315 Enable (disable) any implementation-defined special control
316 characters not currently controlled by icanon, isig, ixon,
317 or ixoff. This shall have the effect of setting (not set‐
318 ting) IEXTEN in the termios c_lflag field, as defined in
319 the Base Definitions volume of POSIX.1‐2008, Chapter 11,
320 General Terminal Interface.
321 echo (−echo)
323 Echo back (do not echo back) every character typed. This
324 shall have the effect of setting (not setting) ECHO in the
325 termios c_lflag field, as defined in the Base Definitions
326 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
327 face.
328 echoe (−echoe)
330 The ERASE character visually erases (does not erase) the
331 last character in the current line from the display, if
332 possible. This shall have the effect of setting (not set‐
333 ting) ECHOE in the termios c_lflag field, as defined in the
334 Base Definitions volume of POSIX.1‐2008, Chapter 11, Gen‐
335 eral Terminal Interface.
336 echok (−echok)
338 Echo (do not echo) NL after KILL character. This shall have
339 the effect of setting (not setting) ECHOK in the termios
340 c_lflag field, as defined in the Base Definitions volume of
341 POSIX.1‐2008, Chapter 11, General Terminal Interface.
342 echonl (−echonl)
344 Echo (do not echo) NL, even if echo is disabled. This shall
345 have the effect of setting (not setting) ECHONL in the
346 termios c_lflag field, as defined in the Base Definitions
347 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
348 face.
349 noflsh (−noflsh)
351 Disable (enable) flush after INTR, QUIT, SUSP. This shall
352 have the effect of setting (not setting) NOFLSH in the
353 termios c_lflag field, as defined in the Base Definitions
354 volume of POSIX.1‐2008, Chapter 11, General Terminal Inter‐
355 face.
356 tostop (−tostop)
358 Send SIGTTOU for background output. This shall have the
359 effect of setting (not setting) TOSTOP in the termios
360 c_lflag field, as defined in the Base Definitions volume of
361 POSIX.1‐2008, Chapter 11, General Terminal Interface.
362 Special Control Character Assignments
364 <control>‐character string
365 Set <control>‐character to string. If <control>‐character is one
366 of the character sequences in the first column of the following
367 table, the corresponding the Base Definitions volume of
368 POSIX.1‐2008, Chapter 11, General Terminal Interface control
369 character from the second column shall be recognized. This has
370 the effect of setting the corresponding element of the termios
371 c_cc array (see the Base Definitions volume of POSIX.1‐2008,
372 Chapter 13, Headers, <termios.h>).
373 Table: Control Character Names in stty
375 ┌──────────────────┬────────────────┬─────────────────┐
377 │Control Character │ c_cc Subscript │ Description │
378 ├──────────────────┼────────────────┼─────────────────┤
379 │eof │ VEOF │ EOF character │
380 │eol │ VEOL │ EOL character │
381 │erase │ VERASE │ ERASE character │
382 │intr │ VINTR │ INTR character │
383 │kill │ VKILL │ KILL character │
384 │quit │ VQUIT │ QUIT character │
385 │susp │ VSUSP │ SUSP character │
386 │start │ VSTART │ START character │
387 │stop │ VSTOP │ STOP character │
388 └──────────────────┴────────────────┴─────────────────┘
389 If string is a single character, the control character shall be
390 set to that character. If string is the two-character sequence
391 "^−" or the string undef, the control character shall be set to
392 _POSIX_VDISABLE , if it is in effect for the device; if
393 _POSIX_VDISABLE is not in effect for the device, it shall be
394 treated as an error. In the POSIX locale, if string is a two-
395 character sequence beginning with <circumflex> ('^'), and the
396 second character is one of those listed in the "^c" column of the
397 following table, the control character shall be set to the corre‐
398 sponding character value in the Value column of the table.
399 Table: Circumflex Control Characters in stty
401 ┌──────────────┬────────────────┬──────────────┐
403 │ ^c Value │ ^c Value │ ^c Value │
404 ├──────────────┼────────────────┼──────────────┤
405 │a, A <SOH> │ l, L <FF> │ w, W <ETB> │
406 │b, B <STX> │ m, M <CR> │ x, X <CAN> │
407 │c, C <ETX> │ n, N <SO> │ y, Y <EM> │
408 │d, D <EOT> │ o, O <SI> │ z, Z <SUB> │
409 │e, E <ENQ> │ p, P <DLE> │ [ <ESC> │
410 │f, F <ACK> │ q, Q <DC1> │ \ <FS> │
411 │g, G <BEL> │ r, R <DC2> │ ] <GS> │
412 │h, H <BS> │ s, S <DC3> │ ^ <RS> │
413 │i, I <HT> │ t, T <DC4> │ _ <US> │
414 │j, J <LF> │ u, U <NAK> │ ? <DEL> │
415 │k, K <VT> │ v, V <SYN> │ │
416 └──────────────┴────────────────┴──────────────┘
417 min number
418 Set the value of MIN to number. MIN is used in non-canonical
419 mode input processing (icanon).
420 time number
422 Set the value of TIME to number. TIME is used in non-canonical
423 mode input processing (icanon).
424 Combination Modes
426 saved settings
427 Set the current terminal characteristics to the saved settings
428 produced by the −g option.
429 evenp or parity
431 Enable parenb and cs7; disable parodd.
432 oddp
434 Enable parenb, cs7, and parodd.
435 −parity, −evenp, or −oddp
437 Disable parenb, and set cs8.
438 raw (−raw or cooked)
440 Enable (disable) raw input and output. Raw mode shall be equiva‐
441 lent to setting:
442 stty cs8 erase ^− kill ^− intr ^− \
444 quit ^− eof ^− eol ^− −post −inpck
445 nl (−nl)
447 Disable (enable) icrnl. In addition, −nl unsets inlcr and igncr.
448 ek Reset ERASE and KILL characters back to system defaults.
450 sane
452 Reset all modes to some reasonable, unspecified, values.
453
455 Although no input is read from standard input, standard input shall be
456 used to get the current terminal I/O characteristics and to set new
457 terminal I/O characteristics.
458
460 None.
461
463 The following environment variables shall affect the execution of stty:
464 LANG Provide a default value for the internationalization vari‐
466 ables that are unset or null. (See the Base Definitions vol‐
467 ume of POSIX.1‐2008, Section 8.2, Internationalization Vari‐
468 ables for the precedence of internationalization variables
469 used to determine the values of locale categories.)
470 LC_ALL If set to a non-empty string value, override the values of
472 all the other internationalization variables.
473 LC_CTYPE This variable determines the locale for the interpretation of
475 sequences of bytes of text data as characters (for example,
476 single-byte as opposed to multi-byte characters in arguments)
477 and which characters are in the class print.
478 LC_MESSAGES
480 Determine the locale that should be used to affect the format
481 and contents of diagnostic messages written to standard
482 error.
483 NLSPATH Determine the location of message catalogs for the processing
485 of LC_MESSAGES.
486
488 Default.
489
491 If operands are specified, no output shall be produced.
492 If the −g option is specified, stty shall write to standard output the
494 current settings in a form that can be used as arguments to another
495 instance of stty on the same system.
496 If the −a option is specified, all of the information as described in
498 the OPERANDS section shall be written to standard output. Unless other‐
499 wise specified, this information shall be written as <space>-separated
500 tokens in an unspecified format, on one or more lines, with an unspeci‐
501 fied number of tokens per line. Additional information may be written.
502 If no options or operands are specified, an unspecified subset of the
504 information written for the −a option shall be written.
505 If speed information is written as part of the default output, or if
507 the −a option is specified and if the terminal input speed and output
508 speed are the same, the speed information shall be written as follows:
509 "speed %d baud;", <speed>
511 Otherwise, speeds shall be written as:
513 "ispeed %d baud; ospeed %d baud;", <ispeed>, <ospeed>
515 In locales other than the POSIX locale, the word baud may be changed to
517 something more appropriate in those locales.
518 If control characters are written as part of the default output, or if
520 the −a option is specified, control characters shall be written as:
521 "%s = %s;", <control-character name>, <value>
523 where <value> is either the character, or some visual representation of
525 the character if it is non-printable, or the string undef if the char‐
526 acter is disabled.
527
529 The standard error shall be used only for diagnostic messages.
530
532 None.
533
535 None.
536
538 The following exit values shall be returned:
539 0 The terminal options were read or set successfully.
541 >0 An error occurred.
543
545 Default.
546 The following sections are informative.
548
550 The −g flag is designed to facilitate the saving and restoring of ter‐
551 minal state from the shell level. For example, a program may:
552 saveterm="$(stty −g)" # save terminal state
554 stty (new settings) # set new state
555 ... # ...
556 stty $saveterm # restore terminal state
557 Since the format is unspecified, the saved value is not portable across
559 systems.
560 Since the −a format is so loosely specified, scripts that save and
562 restore terminal settings should use the −g option.
563
565 None.
566
568 The original stty description was taken directly from System V and
569 reflected the System V terminal driver termio. It has been modified to
570 correspond to the terminal driver termios.
571 Output modes are specified only for XSI-conformant systems. All imple‐
573 mentations are expected to provide stty operands corresponding to all
574 of the output modes they support.
575 The stty utility is primarily used to tailor the user interface of the
577 terminal, such as selecting the preferred ERASE and KILL characters. As
578 an application programming utility, stty can be used within shell
579 scripts to alter the terminal settings for the duration of the script.
580 The termios section states that individual disabling of control charac‐
582 ters is possible through the option _POSIX_VDISABLE. If enabled, two
583 conventions currently exist for specifying this: System V uses "^−",
584 and BSD uses undef. Both are accepted by stty in this volume of
585 POSIX.1‐2008. The other BSD convention of using the letter 'u' was
586 rejected because it conflicts with the actual letter 'u', which is an
587 acceptable value for a control character.
588 Early proposals did not specify the mapping of "^c" to control charac‐
590 ters because the control characters were not specified in the POSIX
591 locale character set description file requirements. The control charac‐
592 ter set is now specified in the Base Definitions volume of
593 POSIX.1‐2008, Chapter 3, Definitions, so the historical mapping is
594 specified. Note that although the mapping corresponds to control-char‐
595 acter key assignments on many terminals that use the ISO/IEC 646:1991
596 standard (or ASCII) character encodings, the mapping specified here is
597 to the control characters, not their keyboard encodings.
598 Since termios supports separate speeds for input and output, two new
600 options were added to specify each distinctly.
601 Some historical implementations use standard input to get and set ter‐
603 minal characteristics; others use standard output. Since input from a
604 login TTY is usually restricted to the owner while output to a TTY is
605 frequently open to anyone, using standard input provides fewer chances
606 of accidentally (or maliciously) altering the terminal settings of
607 other users. Using standard input also allows stty −a and stty −g out‐
608 put to be redirected for later use. Therefore, usage of standard input
609 is required by this volume of POSIX.1‐2008.
610
612 None.
613
615 Chapter 2, Shell Command Language
616 The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
618 Variables, Chapter 11, General Terminal Interface, Section 12.2, Util‐
619 ity Syntax Guidelines, <termios.h>
620
622 Portions of this text are reprinted and reproduced in electronic form
623 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
624 -- Portable Operating System Interface (POSIX), The Open Group Base
625 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
626 cal and Electronics Engineers, Inc and The Open Group. (This is
627 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
628 event of any discrepancy between this version and the original IEEE and
629 The Open Group Standard, the original IEEE and The Open Group Standard
630 is the referee document. The original Standard can be obtained online
631 at http://www.unix.org/online.html .
632 Any typographical or formatting errors that appear in this page are
634 most likely to have been introduced during the conversion of the source
635 files to man page format. To report such errors, see https://www.ker‐
636 nel.org/doc/man-pages/reporting_bugs.html .
637IEEE/The Open Group 2013 STTY(1P)