FreeBSD Man Pages

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 stan-
	     dard input.  The file is opened using the O_NONBLOCK flag of
	     open(), making it possible to set or display settings on a termi-
	     nal 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
	     invocation 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 characteris-
     tics:

   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 possi-
		 ble.  If the input baud rate is set to zero, the input baud
		 rate is set to the value of the output baud rate.

     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 char-
		 acter restarts output.

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

		 (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 func-
		 tion.

   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 spe-
		 cial 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.

		 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 back-
		 wards within ``\'' and ``/''.	Otherwise, disable this fea-
		 ture.

     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 out-
		 put.

     altwerase (-altwerase)
		 Use (do not use) an alternate word erase algorithm when pro-
		 cessing WERASE characters.  This alternate algorithm consid-
		 ers sequences of alphanumeric/underscores as words.  It also
		 skips the first preceding character in its classification (as
		 a convenience 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 char-
		 acter, 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
		       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 set-
		 tings 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 termi-
		 nal use.

     tty	 Set the line discipline to the standard terminal line disci-
		 pline 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 wait-
		 ing 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)

		 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 pre-
		 viously in effect.  To set the terminal into a raw state and
		 then accurately restore it, the following shell code is rec-
		 ommended:

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

     size	 The size of the terminal is printed as two numbers on a sin-
		 gle 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.

     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'') compati-
     ble.  The flags -e and -f are extensions to the standard.

FreeBSD 5.4			April 18, 1994			   FreeBSD 5.4

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