STTY(1) 						    BSD General Commands Manual 						   STTY(1)

NAME

     stty -- set the options for a terminal device interface

SYNOPSIS

     stty [-a | -e | -g] [-f file] [operands]

DESCRIPTION

     The stty utility sets or reports on terminal characteristics for the device that is its standard input.  If no options or operands are speci-
     fied, it reports the settings of a subset of characteristics as well as additional ones if they differ from their default values.	Otherwise
     it modifies the terminal state according to the specified arguments.  Some combinations of arguments are mutually exclusive on some terminal
     types.

     The following options are available:

     -a      Display all the current settings for the terminal to standard output as per IEEE Std 1003.2 (``POSIX.2'').

     -e      Display all the current settings for the terminal to standard output in the traditional BSD ``all'' and ``everything'' formats.

     -f      Open and use the terminal named by file rather than using standard input.	The file is opened using the O_NONBLOCK flag of open(),
	     making it possible to set or display settings on a terminal that might otherwise block on the open.

     -g      Display all the current settings for the terminal to standard output in a form that may be used as an argument to a subsequent invo-
	     cation of stty to restore the current terminal state as per IEEE Std 1003.2 (``POSIX.2'').

     The following arguments are available to set the terminal characteristics:

   Control Modes:
     Control mode flags affect hardware characteristics associated with the terminal.  This corresponds to the c_cflag in the termios structure.

     parenb (-parenb)
		 Enable (disable) parity generation and detection.

     parodd (-parodd)
		 Select odd (even) parity.

     cs5 cs6 cs7 cs8
		 Select character size, if possible.

     number	 Set terminal baud rate to the number given, if possible.  If the baud rate is set to zero, modem control is no longer asserted.

     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 is set
		 to the value of the output baud rate.

     ospeed number
		 Set terminal output baud rate to the number given, if possible.  If the output baud rate is set to zero, modem control is no
		 longer asserted.

     speed number
		 This sets both ispeed and ospeed to number.

     hupcl (-hupcl)
		 Stop asserting modem control (do not stop asserting modem control) on last close.

     hup (-hup)  Same as hupcl (-hupcl).

     cstopb (-cstopb)
		 Use two (one) stop bits per character.

     cread (-cread)
		 Enable (disable) the receiver.

     clocal (-clocal)
		 Assume a line without (with) modem control.

     crtscts (-crtscts)
		 Enable (disable) RTS/CTS flow control.

   Input Modes:
     This corresponds to the c_iflag in the termios structure.

     ignbrk (-ignbrk)
		 Ignore (do not ignore) break on input.

     brkint (-brkint)
		 Signal (do not signal) INTR on break.

     ignpar (-ignpar)
		 Ignore (do not ignore) characters with parity errors.

     parmrk (-parmrk)
		 Mark (do not mark) characters with parity errors.

     inpck (-inpck)
		 Enable (disable) input parity checking.

     istrip (-istrip)
		 Strip (do not strip) input characters to seven bits.

     inlcr (-inlcr)
		 Map (do not map) NL to CR on input.

     igncr (-igncr)
		 Ignore (do not ignore) CR on input.

     icrnl (-icrnl)
		 Map (do not map) CR to NL on input.

     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, or if ixany is set, any character restarts output.

     ixoff (-ixoff)
		 Request that the system send (not send) START/STOP characters when the input queue is nearly empty/full.

     ixany (-ixany)
		 Allow any character (allow only START) to restart output.

     imaxbel (-imaxbel)
		 The system imposes a limit of MAX_INPUT (currently 255) characters in the input queue.  If imaxbel is set and the input queue
		 limit has been reached, subsequent input causes the system to send an ASCII BEL character to the output queue (the terminal beeps
		 at you).  Otherwise, if imaxbel is unset and the input queue is full, the next input character causes the entire input and output
		 queues to be discarded.

   Output Modes:
     This corresponds to the c_oflag of the termios structure.

     opost (-opost)
		 Post-process output (do not post-process output; ignore all other output modes).

     onlcr (-onlcr)
		 Map (do not map) NL to CR-NL on output.

     ocrnl (-ocrnl)
		 Map (do not map) CR to NL on output.

     oxtabs (-oxtabs)
		 Expand (do not expand) tabs to spaces on output.

     onocr (-onocr)
		 Do not (do) output CRs at column zero.

     onlret (-onlret)
		 On the terminal NL performs (does not perform) the CR function.

   Local Modes:
     Local mode flags (lflags) affect various and sundry characteristics of terminal processing.  Historically the term "local" pertained to new
     job control features implemented by Jim Kulp on a Pdp 11/70 at IIASA.  Later the driver ran on the first VAX at Evans Hall, UC Berkeley,
     where the job control details were greatly modified but the structure definitions and names remained essentially unchanged.  The second
     interpretation of the 'l' in lflag is ``line discipline flag'' which corresponds to the c_lflag of the termios structure.

     isig (-isig)
		 Enable (disable) the checking of characters against the special control characters INTR, QUIT, and SUSP.

     icanon (-icanon)
		 Enable (disable) canonical input (ERASE and KILL processing).

     iexten (-iexten)
		 Enable (disable) any implementation defined special control characters not currently controlled by icanon, isig, or ixon.

     echo (-echo)
		 Echo back (do not echo back) every character typed.

     echoe (-echoe)
		 The ERASE character shall (shall not) visually erase the last character in the current line from the display, if possible.

     echok (-echok)
		 Echo (do not echo) NL after KILL character.

     echoke (-echoke)
		 The KILL character shall (shall not) visually erase the current line from the display, if possible.

     echonl (-echonl)
		 Echo (do not echo) NL, even if echo is disabled.

     echoctl (-echoctl)
		 If echoctl is set, echo control characters as ^X.  Otherwise control characters echo as themselves.

     echoprt (-echoprt)
		 For printing terminals.  If set, echo erased characters backwards within ``'' and ``/''.  Otherwise, disable this feature.

     noflsh (-noflsh)
		 Disable (enable) flush after INTR, QUIT, SUSP.

     tostop (-tostop)
		 Send (do not send) SIGTTOU for background output.  This causes background jobs to stop if they attempt terminal output.

     altwerase (-altwerase)
		 Use (do not use) an alternate word erase algorithm when processing WERASE characters.	This alternate algorithm considers
		 sequences of alphanumeric/underscores as words.  It also skips the first preceding character in its classification (as a conve-
		 nience since the one preceding character could have been erased with simply an ERASE character.)

     mdmbuf (-mdmbuf)
		 If set, flow control output based on condition of Carrier Detect.  Otherwise writes return an error if Carrier Detect is low (and
		 Carrier is not being ignored with the CLOCAL flag.)

     flusho (-flusho)
		 Indicates output is (is not) being discarded.

     pendin (-pendin)
		 Indicates input is (is not) pending after a switch from non-canonical to canonical mode and will be re-input when a read becomes
		 pending or more input arrives.

   Control Characters:
     control-character string
		 Set control-character to string.  If string is a single character, the control character is set to that character.  If string is
		 the two character sequence "^-" or the string "undef" the control character is disabled (i.e. set to {_POSIX_VDISABLE}.)

		 Recognized control-characters:

		       control-
		       character    Subscript	 Description
		       _________    _________	 _______________
		       eof	    VEOF	 EOF character
		       eol	    VEOL	 EOL character
		       eol2	    VEOL2	 EOL2 character
		       erase	    VERASE	 ERASE character
		       erase2	    VERASE2	 ERASE2 character
		       werase	    VWERASE	 WERASE 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
		       dsusp	    VDSUSP	 DSUSP character
		       lnext	    VLNEXT	 LNEXT character
		       reprint	    VREPRINT	 REPRINT character
		       status	    VSTATUS	 STATUS character

     min number

     time number
		 Set the value of min or time to number.  MIN and TIME are 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, -oddp
		 Disable parenb, and set cs8.

     nl (-nl)	 Enable (disable) icrnl.  In addition -nl unsets inlcr and igncr.

     ek 	 Reset ERASE, ERASE2, and KILL characters back to system defaults.

     sane	 Resets all modes to reasonable values for interactive terminal use.

     tty	 Set the line discipline to the standard terminal line discipline TTYDISC.

     crt (-crt)  Set (disable) all modes suitable for a CRT display device.

     kerninfo (-kerninfo)
		 Enable (disable) the system generated status line associated with processing a STATUS character (usually set to ^T).  The status
		 line consists of the system load average, the current command name, its process ID, the event the process is waiting on (or the
		 status of the process), the user and system times, percent cpu, and current memory usage.

     columns number
		 The terminal size is recorded as having number columns.

     cols number
		 is an alias for columns.

     rows number
		 The terminal size is recorded as having number rows.

     dec	 Set modes suitable for users of Digital Equipment Corporation systems (ERASE, KILL, and INTR characters are set to ^?, ^U, and
		 ^C; ixany is disabled, and crt is enabled.)

     extproc (-extproc)
		 If set, this flag indicates that some amount of terminal processing is being performed by either the terminal hardware or by the
		 remote side connected to a pty.

     raw (-raw)  If set, change the modes of the terminal so that no input or output processing is performed.  If unset, change the modes of the
		 terminal to some reasonable state that performs input and output processing.  Note that since the terminal driver no longer has a
		 single RAW bit, it is not possible to intuit what flags were set prior to setting raw.  This means that unsetting raw may not put
		 back all the setting that were previously in effect.  To set the terminal into a raw state and then accurately restore it, the
		 following shell code is recommended:

		 save_state=$(stty -g)
		 stty raw
		 ...
		 stty "$save_state"

     size	 The size of the terminal is printed as two numbers on a single line, first rows, then columns.

   Compatibility Modes:
     These modes remain for compatibility with the previous version of the stty command.

     all	 Reports all the terminal modes as with stty -a except that the control characters are printed in a columnar format.

     everything  Same as all.

     cooked	 Same as sane.

     cbreak	 If set, enables brkint, ixon, imaxbel, opost, isig, iexten, and -icanon.  If unset, same as sane.

     new	 Same as tty.

     old	 Same as tty.

     newcrt (-newcrt)
		 Same as crt.

     pass8	 The converse of parity.

     tandem (-tandem)
		 Same as ixoff.

     decctlq (-decctlq)
		 The converse of ixany.

     crterase (-crterase)
		 Same as echoe.

     crtbs (-crtbs)
		 Same as echoe.

     crtkill (-crtkill)
		 Same as echoke.

     ctlecho (-ctlecho)
		 Same as echoctl.

     prterase (-prterase)
		 Same as echoprt.

     litout (-litout)
		 The converse of opost.

     tabs (-tabs)
		 The converse of oxtabs.

     brk value	 Same as the control character eol.

     flush value
		 Same as the control character discard.

     rprnt value
		 Same as the control character reprint.

DIAGNOSTICS

     The stty utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

     termios(4)

STANDARDS

     The stty utility is expected to be IEEE Std 1003.2 (``POSIX.2'') compatible.  The flags -e and -f are extensions to the standard.

BSD
								  April 18, 1994							       BSD