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PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       stty — set the options for a terminal

SYNOPSIS

       stty [-a|-g]

       stty operand...

DESCRIPTION

       The  stty  utility shall set or report on terminal I/O characteristics for the device that
       is its standard input. Without options or operands specified, it shall report the settings
       of   certain  characteristics,  usually  those  that  differ  from  implementation-defined
       defaults.  Otherwise, it shall modify  the  terminal  state  according  to  the  specified
       operands.  Detailed  information about the modes listed in the first five groups below are
       described in the Base Definitions volume of POSIX.1‐2017,  Chapter  11,  General  Terminal
       Interface.    Operands  in  the  Combination  Modes  group  (see  Combination  Modes)  are
       implemented using operands in the previous  groups.  Some  combinations  of  operands  are
       mutually-exclusive  on  some  terminal  types;  the results of using such combinations are
       unspecified.

       Typical implementations of this utility require a communications line  configured  to  use
       the  termios interface defined in the System Interfaces volume of POSIX.1‐2017. On systems
       where none of these lines are available, and on lines not currently configured to  support
       the termios interface, some of the operands need not affect terminal characteristics.

OPTIONS

       The  stty  utility  shall  conform to the Base Definitions volume of POSIX.1‐2017, Section
       12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       -a        Write to standard output all the current settings for the terminal.

       -g        Write to standard output all the current settings in an  unspecified  form  that
                 can  be  used as arguments to another invocation of the stty utility on the same
                 system. The form used shall  not  contain  any  characters  that  would  require
                 quoting to avoid word expansion by the shell; see Section 2.6, Word Expansions.

OPERANDS

       The following operands shall be supported to set the terminal characteristics.

   Control Modes
       parenb (-parenb)
                   Enable  (disable)  parity generation and detection. This shall have the effect
                   of setting (not setting) PARENB in the termios c_cflag field,  as  defined  in
                   the  Base  Definitions  volume  of  POSIX.1‐2017, Chapter 11, General Terminal
                   Interface.

       parodd (-parodd)
                   Select odd (even) parity. This shall have the effect of setting (not  setting)
                   PARODD in the termios c_cflag field, as defined in the Base Definitions volume
                   of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       cs5 cs6 cs7 cs8
                   Select character size, if possible. This shall have the effect of setting CS5,
                   CS6,  CS7,  and CS8, respectively, in the termios c_cflag field, as defined in
                   the Base Definitions volume of  POSIX.1‐2017,  Chapter  11,  General  Terminal
                   Interface.

       number      Set  terminal  baud rate to the number given, if possible. If the baud rate is
                   set to zero, the modem control lines shall no longer be asserted.  This  shall
                   have  the  effect  of setting the input and output termios baud rate values as
                   defined in the Base Definitions volume of POSIX.1‐2017,  Chapter  11,  General
                   Terminal Interface.

       ispeed number
                   Set  terminal  input  baud rate to the number given, if possible. If the input
                   baud rate is set to zero, the input baud rate shall be specified by the  value
                   of  the  output  baud  rate.  This  shall have the effect of setting the input
                   termios baud rate  values  as  defined  in  the  Base  Definitions  volume  of
                   POSIX.1‐2017, Chapter 11, General Terminal Interface.

       ospeed number
                   Set  terminal output baud rate to the number given, if possible. If the output
                   baud rate is set to zero, the modem control lines shall no longer be asserted.
                   This  shall  have the effect of setting the output termios baud rate values as
                   defined in the Base Definitions volume of POSIX.1‐2017,  Chapter  11,  General
                   Terminal Interface.

       hupcl (-hupcl)
                   Stop asserting modem control lines (do not stop asserting modem control lines)
                   on last close. This shall have the effect of setting (not  setting)  HUPCL  in
                   the  termios  c_cflag  field,  as  defined  in  the Base Definitions volume of
                   POSIX.1‐2017, Chapter 11, General Terminal Interface.

       hup (-hup)  Equivalent to hupcl(-hupcl).

       cstopb (-cstopb)
                   Use two (one) stop bits per character. This shall have the effect  of  setting
                   (not  setting)  CSTOPB  in  the  termios c_cflag field, as defined in the Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       cread (-cread)
                   Enable (disable) the receiver. This shall have  the  effect  of  setting  (not
                   setting)  CREAD  in  the  termios  c_cflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       clocal (-clocal)
                   Assume a line without (with) modem control. This  shall  have  the  effect  of
                   setting  (not  setting) CLOCAL in the termios c_cflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       It  is  unspecified whether stty shall report an error if an attempt to set a Control Mode
       fails.

   Input Modes
       ignbrk (-ignbrk)
                   Ignore (do not ignore) break on input. This shall have the effect  of  setting
                   (not  setting)  IGNBRK  in  the  termios c_iflag field, as defined in the Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       brkint (-brkint)
                   Signal (do not signal) INTR on break. This shall have the  effect  of  setting
                   (not  setting)  BRKINT  in  the  termios c_iflag field, as defined in the Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       ignpar (-ignpar)
                   Ignore (do not ignore) bytes with parity errors. This shall have the effect of
                   setting  (not  setting) IGNPAR in the termios c_iflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       parmrk (-parmrk)
                   Mark  (do  not mark) parity errors. This shall have the effect of setting (not
                   setting) PARMRK  in  the  termios  c_iflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       inpck (-inpck)
                   Enable  (disable) input parity checking. This shall have the effect of setting
                   (not setting) INPCK in the termios c_iflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       istrip (-istrip)
                   Strip  (do  not  strip)  input  characters  to seven bits. This shall have the
                   effect of setting (not setting)  ISTRIP  in  the  termios  c_iflag  field,  as
                   defined  in  the  Base Definitions volume of POSIX.1‐2017, Chapter 11, General
                   Terminal Interface.

       inlcr (-inlcr)
                   Map (do not map) NL to CR on input. This shall have the effect of setting (not
                   setting)  INLCR  in  the  termios  c_iflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       igncr (-igncr)
                   Ignore (do not ignore) CR on input. This shall have the effect of setting (not
                   setting)  IGNCR  in  the  termios  c_iflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       icrnl (-icrnl)
                   Map (do not map) CR to NL on input. This shall have the effect of setting (not
                   setting)  ICRNL  in  the  termios  c_iflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       ixon (-ixon)
                   Enable (disable) START/STOP output control. Output from the system is  stopped
                   when the system receives STOP and started when the system receives START. This
                   shall have the effect of setting (not setting) IXON  in  the  termios  c_iflag
                   field,  as defined in the Base Definitions volume of POSIX.1‐2017, Chapter 11,
                   General Terminal Interface.

       ixany (-ixany)
                   Allow any character to restart output. This shall have the effect  of  setting
                   (not  setting)  IXANY  in  the  termios  c_iflag field, as defined in the Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       ixoff (-ixoff)
                   Request that the system send (not send) STOP characters when the  input  queue
                   is  nearly  full and START characters to resume data transmission.  This shall
                   have the effect of setting (not setting) IXOFF in the termios  c_iflag  field,
                   as defined in the Base Definitions volume of POSIX.1‐2017, Chapter 11, General
                   Terminal Interface.

   Output Modes
       opost (-opost)
                   Post-process output (do not  post-process  output;  ignore  all  other  output
                   modes).  This  shall  have  the  effect  of setting (not setting) OPOST in the
                   termios  c_oflag  field,  as  defined  in  the  Base  Definitions  volume   of
                   POSIX.1‐2017, Chapter 11, General Terminal Interface.

       onlcr (-onlcr)
                   Map  (do not map) NL to CR-NL on output. This shall have the effect of setting
                   (not setting) ONLCR in the termios c_oflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       ocrnl (-ocrnl)
                   Map  (do  not  map)  CR to NL on output. This shall have the effect of setting
                   (not setting) OCRNL in the termios c_oflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       onocr (-onocr)
                   Do  not  (do)  output CR at column zero. This shall have the effect of setting
                   (not setting) ONOCR in the termios c_oflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       onlret (-onlret)
                   The  terminal  newline  key performs (does not perform) the CR function.  This
                   shall have the effect of setting (not setting) ONLRET in the  termios  c_oflag
                   field,  as defined in the Base Definitions volume of POSIX.1‐2017, Chapter 11,
                   General Terminal Interface.

       ofill (-ofill)
                   Use fill characters (use timing) for delays. This shall  have  the  effect  of
                   setting  (not  setting)  OFILL in the termios c_oflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       ofdel (-ofdel)
                   Fill  characters  are  DELs (NULs). This shall have the effect of setting (not
                   setting)  OFDEL  in  the  termios  c_oflag  field,  as  defined  in  the  Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       cr0 cr1 cr2 cr3
                   Select the style of delay for CRs. This shall have the effect of setting CRDLY
                   to CR0, CR1, CR2, or CR3, respectively,  in  the  termios  c_oflag  field,  as
                   defined  in  the  Base Definitions volume of POSIX.1‐2017, Chapter 11, General
                   Terminal Interface.

       nl0 nl1     Select the style of delay for NL. This shall have the effect of setting  NLDLY
                   to  NL0  or NL1, respectively, in the termios c_oflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       tab0 tab1 tab2 tab3
                   Select  the  style of delay for horizontal tabs. This shall have the effect of
                   setting TABDLY to TAB0, TAB1, TAB2, or  TAB3,  respectively,  in  the  termios
                   c_oflag  field,  as  defined  in  the Base Definitions volume of POSIX.1‐2017,
                   Chapter 11, General Terminal Interface.  Note that  TAB3  has  the  effect  of
                   expanding <tab> characters to <space> characters.

       tabs (-tabs)
                   Synonym for tab0 (tab3).

       bs0 bs1     Select  the  style  of  delay  for <backspace> characters. This shall have the
                   effect of setting BSDLY to BS0 or BS1, respectively, in  the  termios  c_oflag
                   field,  as defined in the Base Definitions volume of POSIX.1‐2017, Chapter 11,
                   General Terminal Interface.

       ff0 ff1     Select the style of delay for <form-feed>  characters.  This  shall  have  the
                   effect  of  setting  FFDLY to FF0 or FF1, respectively, in the termios c_oflag
                   field, as defined in the Base Definitions volume of POSIX.1‐2017, Chapter  11,
                   General Terminal Interface.

       vt0 vt1     Select  the  style of delay for <vertical-tab> characters. This shall have the
                   effect of setting VTDLY to VT0 or VT1, respectively, in  the  termios  c_oflag
                   field,  as defined in the Base Definitions volume of POSIX.1‐2017, Chapter 11,
                   General Terminal Interface.

   Local Modes
       isig (-isig)
                   Enable (disable) the  checking  of  characters  against  the  special  control
                   characters  INTR,  QUIT,  and SUSP. This shall have the effect of setting (not
                   setting) ISIG in the termios c_lflag field, as defined in the Base Definitions
                   volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

       icanon (-icanon)
                   Enable  (disable) canonical input (ERASE and KILL processing). This shall have
                   the effect of setting (not setting) ICANON in the termios  c_lflag  field,  as
                   defined  in  the  Base Definitions volume of POSIX.1‐2017, Chapter 11, General
                   Terminal Interface.

       iexten (-iexten)
                   Enable (disable) any implementation-defined  special  control  characters  not
                   currently  controlled  by  icanon,  isig, ixon, or ixoff.  This shall have the
                   effect of setting (not setting)  IEXTEN  in  the  termios  c_lflag  field,  as
                   defined  in  the  Base Definitions volume of POSIX.1‐2017, Chapter 11, General
                   Terminal Interface.

       echo (-echo)
                   Echo back (do not echo back) every character typed. This shall have the effect
                   of  setting (not setting) ECHO in the termios c_lflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       echoe (-echoe)
                   The ERASE character visually erases (does not erase) the last character in the
                   current line from the display, if possible. This  shall  have  the  effect  of
                   setting  (not  setting)  ECHOE in the termios c_lflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       echok (-echok)
                   Echo  (do  not  echo)  NL  after KILL character. This shall have the effect of
                   setting (not setting) ECHOK in the termios c_lflag field, as  defined  in  the
                   Base   Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General  Terminal
                   Interface.

       echonl (-echonl)
                   Echo (do not echo) NL, even if echo is disabled. This shall have the effect of
                   setting  (not  setting) ECHONL in the termios c_lflag field, as defined in the
                   Base  Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General   Terminal
                   Interface.

       noflsh (-noflsh)
                   Disable  (enable)  flush after INTR, QUIT, SUSP. This shall have the effect of
                   setting (not setting) NOFLSH in the termios c_lflag field, as defined  in  the
                   Base   Definitions  volume  of  POSIX.1‐2017,  Chapter  11,  General  Terminal
                   Interface.

       tostop (-tostop)
                   Send SIGTTOU for background output. This shall have the effect of setting (not
                   setting)  TOSTOP  in  the  termios  c_lflag  field,  as  defined  in  the Base
                   Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface.

   Special Control Character Assignments
       <control>‐character string
             Set <control>‐character to string.  If <control>‐character is one of  the  character
             sequences  in  the  first  column of the following table, the corresponding the Base
             Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal  Interface  control
             character from the second column shall be recognized. This has the effect of setting
             the corresponding element of the termios c_cc array (see the Base Definitions volume
             of POSIX.1‐2017, Chapter 13, Headers, <termios.h>).

                                    Table: Control Character Names in stty

                            ┌──────────────────┬────────────────┬─────────────────┐
                            │Control Characterc_cc SubscriptDescription   │
                            ├──────────────────┼────────────────┼─────────────────┤
                            │eof               │ VEOF           │ EOF character   │
                            │eol               │ VEOL           │ EOL character   │
                            │erase             │ VERASE         │ ERASE character │
                            │intr              │ VINTR          │ INTR character  │
                            │kill              │ VKILL          │ KILL character  │
                            │quit              │ VQUIT          │ QUIT character  │
                            │susp              │ VSUSP          │ SUSP character  │
                            │start             │ VSTART         │ START character │
                            │stop              │ VSTOP          │ STOP character  │
                            └──────────────────┴────────────────┴─────────────────┘
             If  string  is  a  single  character,  the  control  character  shall be set to that
             character. If string is the two-character sequence "^-" or  the  string  undef,  the
             control  character  shall  be  set  to  _POSIX_VDISABLE , if it is in effect for the
             device; if _POSIX_VDISABLE is not in effect for the device, it shall be  treated  as
             an  error. In the POSIX locale, if string is a two-character sequence beginning with
             <circumflex> ('^'), and the second character is one of  those  listed  in  the  "^c"
             column  of  the  following  table,  the  control  character  shall  be  set  to  the
             corresponding character value in the Value column of the table.

                                 Table: Circumflex Control Characters in stty

                               ┌──────────────┬────────────────┬──────────────┐
                               │ ^c   Value^c   Value^c   Value │
                               ├──────────────┼────────────────┼──────────────┤
                               │a, A  <SOH>   │  l, L  <FF>    │  w, W  <ETB> │
                               │b, B  <STX>   │  m, M  <CR>    │  x, X  <CAN> │
                               │c, C  <ETX>   │  n, N  <SO>    │  y, Y  <EM>  │
                               │d, D  <EOT>   │  o, O  <SI>    │  z, Z  <SUB> │
                               │e, E  <ENQ>   │  p, P  <DLE>   │  [     <ESC> │
                               │f, F  <ACK>   │  q, Q  <DC1>   │  \     <FS>  │
                               │g, G  <BEL>   │  r, R  <DC2>   │  ]     <GS>  │
                               │h, H  <BS>    │  s, S  <DC3>   │  ^     <RS>  │
                               │i, I  <HT>    │  t, T  <DC4>   │  _     <US>  │
                               │j, J  <LF>    │  u, U  <NAK>   │  ?     <DEL> │
                               │k, K  <VT>    │  v, V  <SYN>   │              │
                               └──────────────┴────────────────┴──────────────┘
       min number
             Set the value of MIN to number.  MIN is used in non-canonical mode input  processing
             (icanon).

       time number
             Set  the  value  of  TIME  to  number.   TIME  is  used  in non-canonical mode input
             processing (icanon).

   Combination Modes
       saved settings
             Set the current terminal characteristics to the saved settings produced  by  the  -g
             option.

       evenp or parity
             Enable parenb and cs7; disable parodd.

       oddp
             Enable parenb, cs7, and parodd.

       -parity, -evenp, or -oddp
             Disable parenb, and set cs8.

       raw (-raw or cooked)
             Enable (disable) raw input and output. Raw mode shall be equivalent to setting:

                 stty cs8 erase ^- kill ^- intr ^- \
                     quit ^- eof ^- eol ^- -post -inpck

       nl (-nl)
             Disable (enable) icrnl.  In addition, -nl unsets inlcr and igncr.

       ek    Reset ERASE and KILL characters back to system defaults.

       sane
             Reset all modes to some reasonable, unspecified, values.

STDIN

       Although  no  input  is  read from standard input, standard input shall be used to get the
       current terminal I/O characteristics and to set new terminal I/O characteristics.

INPUT FILES

       None.

ENVIRONMENT VARIABLES

       The following environment variables shall affect the execution of stty:

       LANG      Provide a default value for the internationalization variables that are unset or
                 null.   (See   the   Base  Definitions  volume  of  POSIX.1‐2017,  Section  8.2,
                 Internationalization  Variables  for  the  precedence  of   internationalization
                 variables used to determine the values of locale categories.)

       LC_ALL    If  set  to  a  non-empty  string  value,  override  the values of all the other
                 internationalization variables.

       LC_CTYPE  This variable determines the locale for the interpretation of sequences of bytes
                 of  text  data  as characters (for example, single-byte as opposed to multi-byte
                 characters in arguments) and which characters are in the class print.

       LC_MESSAGES
                 Determine the locale that should be used to affect the format  and  contents  of
                 diagnostic messages written to standard error.

       NLSPATH   Determine the location of message catalogs for the processing of LC_MESSAGES.

ASYNCHRONOUS EVENTS

       Default.

STDOUT

       If operands are specified, no output shall be produced.

       If the -g option is specified, stty shall write to standard output the current settings in
       a form that can be used as arguments to another instance of stty on the same system.

       If the -a option is specified, all of the information as described in the OPERANDS section
       shall be written to standard output. Unless otherwise specified, this information shall be
       written as <space>-separated tokens in an unspecified format, on one or more  lines,  with
       an unspecified number of tokens per line. Additional information may be written.

       If  no options or operands are specified, an unspecified subset of the information written
       for the -a option shall be written.

       If speed information is written as part of the default output, or  if  the  -a  option  is
       specified  and  if  the  terminal  input  speed  and  output speed are the same, the speed
       information shall be written as follows:

           "speed %d baud;", <speed>

       Otherwise, speeds shall be written as:

           "ispeed %d baud; ospeed %d baud;", <ispeed>, <ospeed>

       In locales other than the POSIX locale, the word baud may be  changed  to  something  more
       appropriate in those locales.

       If  control  characters  are written as part of the default output, or if the -a option is
       specified, control characters shall be written as:

           "%s = %s;", <control-character name>, <value>

       where <value> is either the character, or some visual representation of the  character  if
       it is non-printable, or the string undef if the character is disabled.

STDERR

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

       None.

EXTENDED DESCRIPTION

       None.

EXIT STATUS

       The following exit values shall be returned:

        0    The terminal options were read or set successfully.

       >0    An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       The  -g flag is designed to facilitate the saving and restoring of terminal state from the
       shell level. For example, a program may:

           saveterm="$(stty -g)"       # save terminal state
           stty (new settings)         # set new state
           ...                         # ...
           stty $saveterm              # restore terminal state

       Since the format is unspecified, the saved value is not portable across systems.

       Since the -a format is so loosely  specified,  scripts  that  save  and  restore  terminal
       settings should use the -g option.

EXAMPLES

       None.

RATIONALE

       The  original stty description was taken directly from System V and reflected the System V
       terminal driver termio.  It has  been  modified  to  correspond  to  the  terminal  driver
       termios.

       Output  modes  are  specified  only  for  XSI-conformant  systems. All implementations are
       expected to provide stty operands corresponding to all of the output modes they support.

       The stty utility is primarily used to tailor the user interface of the terminal,  such  as
       selecting  the preferred ERASE and KILL characters. As an application programming utility,
       stty can be used within shell scripts to alter the terminal settings for the  duration  of
       the script.

       The  termios  section  states  that individual disabling of control characters is possible
       through the option _POSIX_VDISABLE.  If  enabled,  two  conventions  currently  exist  for
       specifying  this:  System  V  uses "^-", and BSD uses undef.  Both are accepted by stty in
       this volume of POSIX.1‐2017. The other BSD convention of using the letter 'u' was rejected
       because  it  conflicts  with  the  actual  letter  'u', which is an acceptable value for a
       control character.

       Early proposals did not specify the mapping of "^c"  to  control  characters  because  the
       control  characters  were not specified in the POSIX locale character set description file
       requirements. The control character set is now specified in the Base Definitions volume of
       POSIX.1‐2017,  Chapter  3,  Definitions, so the historical mapping is specified. Note that
       although the mapping corresponds to control-character key assignments  on  many  terminals
       that  use  the  ISO/IEC 646:1991  standard  (or  ASCII)  character  encodings, the mapping
       specified here is to the control characters, not their keyboard encodings.

       Since termios supports separate speeds for input and output, two new options were added to
       specify each distinctly.

       Some   historical   implementations   use   standard   input   to  get  and  set  terminal
       characteristics; others use standard output. Since input  from  a  login  TTY  is  usually
       restricted to the owner while output to a TTY is frequently open to anyone, using standard
       input provides fewer chances  of  accidentally  (or  maliciously)  altering  the  terminal
       settings of other users. Using standard input also allows stty -a and stty -g output to be
       redirected for later use. Therefore, usage of standard input is required by this volume of
       POSIX.1‐2017.

FUTURE DIRECTIONS

       None.

SEE ALSO

       Chapter 2, Shell Command Language

       The Base Definitions volume of POSIX.1‐2017, Chapter 8, Environment Variables, Chapter 11,
       General Terminal Interface, Section 12.2, Utility Syntax Guidelines, <termios.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1-2017,  Standard  for  Information Technology -- Portable Operating System Interface
       (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C)  2018  by
       the  Institute  of  Electrical  and Electronics Engineers, Inc and The Open Group.  In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard,  the  original  IEEE  and  The  Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most  likely  to  have
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       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .