.\" Copyright (c) 1983 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)stty.1	6.4.1 (2.11BSD) 1997/5/2
.\"
.TH STTY 1 "March 27, 1997"
.UC 4
.SH NAME
stty \- set terminal options
.SH SYNOPSIS
.B stty
[\fB\-a | \-e\fP]
[\fB-f\fP \fIfile\fP]
[operands]
.SH DESCRIPTION
.I Stty
sets certain I/O options on the current output terminal,
placing its output on the diagnostic output.
With no argument, it reports the speed of the terminal and the
settings of the options which are different from their defaults.
.PP
The following options are available:
.TP 10
\fB\-a\fP
Display everything \fIstty\fP knows.  This has the same effect
as using the operand \fBall\fP or \fBeverything\fP.  The distinction between
\fBall\fP and \fBeverything\fP has been removed.
.TP 10
\fB\-e\fP
Same a \fB\-a\fP above.
.TP 10
\fB\-f\fP
Open and use the terminal named by \fIfile\fP rather than using standard
output.  The file is opened using the O_NONBLOCK flag of \fBopen\fP(),
making it possible to set or display settings on a terminal that might
otherwise block on the open.
.PP
The following operands are special:
.TP 12
.B all
Everything
.I stty
knows about is printed.
.TP 12
.B everything
Same as \fBall\fP above.
.TP 12
.B flushout
Flush the queues for the device.  This is most useful when an exiting
process is stuck waiting for terminal output to drain.
.TP 12
.B speed
The terminal speed alone is printed on the standard output.
.TP 12
.B size
The terminal (window) sizes are printed on the standard output,
first rows and then columns.
.PP
\fIOperands\fP are selected from the following:
.TP  10
.B even 
allow even parity input
.br
.ns
.TP 10
.B \-even 
disallow even parity input
.TP 10
.B odd 
allow odd parity input
.br
.ns
.TP 10
.B \-odd 
disallow odd parity input
.TP 10
.B raw 
raw mode input
(\fBno\fR input processing (erase, kill, interrupt, ...); parity bit passed back)
.br
.ns
.TP 10
.B \-raw 
negate raw mode
.TP 10
.B cooked 
same as `\-raw'
.TP 10
.B cbreak
make each character available to
.IR read (2)
as received; no erase and kill processing,
but all other processing (interrupt, suspend, ...) is performed
.br
.ns
.TP 10
.B \-cbreak
make characters available to 
.I read
only when newline is received
.TP 10
.B \-nl 
allow carriage return for new-line,
and output CR-LF for carriage return or new-line
.br
.ns
.TP 10
.B nl 
accept only new-line to end lines
.TP 10
.B echo 
echo back every character typed
.br
.ns
.TP 10
.B \-echo 
do not echo characters
.TP 10
.B tandem
enable inbound software (xon/xoff) flow control, so that the system sends 
out the stop character when
its internal queue is in danger of overflowing on input, and sends the
start character when it is ready to accept further input
.br
.ns
.TP 10
.B \-tandem
disable inbound software (xon/xoff) flow control
.TP 10
.B \-tabs 
replace tabs by spaces when printing
.br
.ns
.TP 10
.B tabs 
preserve tabs
.br
.PP
For the following commands which take a character argument \fIc\fR,
you may also specify \fIc\fR as ``undef'', to set the value
to be undefined.  A value of ``^x'', a 2 character sequence, is also
interpreted as a control character, with ``^?'' representing delete.
.TP 10
.BI erase \ c\fR
set erase character to
.I c
(default `#', but often reset to ^H.)
.br
.ns
.TP 10
.BI kill \ c\fR
set kill character to
.I c
(default `@', but often reset to ^U.)
.br
.ns
.TP 10
.BI intr \ c\fR
set interrupt character to
.I c
(default DEL or ^? (delete), but often reset to ^C.)
.br
.ns
.TP 10
.BI quit \ c\fR
set quit character to
.I c
(default control \e.)
.br
.ns
.TP 10
.BI start \ c\fR
set start character to
.I c
(default control Q.)
.br
.ns
.TP 10
.BI stop \ c\fR
set stop character to
.I c
(default control S.)
.br
.ns
.TP 10
.BI eof \ c\fR
set end of file character to
.I c
(default control D.)
.br
.ns
.TP 10
.BI brk \ c\fR
set break character to
.I c
(default undefined.)
This character is an additional character causing wakeup.
.br
.ns
.TP 10
.B dec
set all modes suitable for Digital Equipment Corp. operating systems
users; (erase, kill, and interrupt characters to ^?, ^U, and ^C,
decctlq and ``newcrt''.)
.ns
.TP 10
.B 0 
hang up phone line immediately
.br
.ns
.TP 10
.B  "50 75 110 134 150 200 300 600 1200 1800 2400 4800 9600 exta extb"
.br
Set terminal baud rate to the number given, if possible.
(These are the speeds supported by the DH-11 interface).
.TP 10
.BI rows \ n\fR
The terminal size is recorded as having
.I n
rows.
.TP 10
.BI columns \ n\fR
The terminal size is recorded as having
.I n
columns.
.TP 10
.BI cols \ n\fR
is an alias for
.IR columns .
.PP
A teletype driver which supports the job control processing of
.IR csh (1)
and more functionality than the basic driver is fully described in
.IR tty (4).
The following options apply only to it.
.TP 10
.B new
Use new driver (switching flushes typeahead).
.br
.ns
.TP 10
.B crt
Set options for a CRT (crtbs, ctlecho and, if >= 1200 baud,
crterase and crtkill.)
.TP 10
.B crtbs
Echo backspaces on erase characters.
.TP 10
.B prterase
For printing terminal echo erased characters backwards within ``\e'' and ``/''.
.TP 10
.B crterase
Wipe out erased characters with ``backspace-space-backspace.''
.br
.ns
.TP 10
.B \-crterase
Leave erased characters visible; just backspace.
.TP 10
.B crtkill
Wipe out input on like kill ala \fBcrterase\fP.
.br
.ns
.TP 10
.B \-crtkill
Just echo line kill character and a newline on line kill.
.TP 10
.B ctlecho
Echo control characters as ``^\fIx\fR'' (and delete as ``^?''.)
Print two backspaces following the EOT character (control D).
.br
.ns
.TP 10
.B \-ctlecho
Control characters echo as themselves; in cooked mode EOT (control-D)
is not echoed.
.TP 10
.B decctlq
After output is suspended (normally by ^S), only a start character
(normally ^Q) will restart it.  This is compatible with DEC's vendor
supplied systems.
.br
.ns
.TP 10
.B \-decctlq
After output is suspended, any character typed will restart it;
the start character will restart output without providing any input.
(This is the default.)
.TP 10
.B tostop
Background jobs stop if they attempt terminal output.
.br
.ns
.TP 10
.B \-tostop
Output from background jobs to the terminal is allowed.
.TP 10
.B flusho
Output is being discarded usually because user hit control O (internal state bit).
.br
.ns
.TP 10
.B \-flusho
Output is not being discarded.
.TP 10
.B pendin
Input is pending after a switch from cbreak to cooked 
and will be re-input when a read becomes pending or more input arrives
(internal state bit).
.br
.ns
.TP 10
.B \-pendin
Input is not pending.
.TP 10
.B pass8
Passes all 8 bits through on input, in any mode.
.br
.ns
.TP 10
.B \-pass8
Strips the 0200 bit on input except in raw mode.
.TP 10
.B mdmbuf
Start/stop output on carrier transitions (not implemented).
.br
.ns
.TP 10
.B \-mdmbuf
Return error if write attempted after carrier drops.
.TP 10
.B litout
Send output characters without any processing.
.br
.ns
.TP 10
.B \-litout
Do normal output processing, inserting delays, etc.
.TP 10
.B nohang
Don't send hangup signal if carrier drops.
.br
.ns
.TP 10
.B \-nohang
Send hangup signal to control process group when carrier drops.
.PP
The following special characters are applicable only to the new
teletype driver
and are not normally changed.
.TP 10
.BI susp \ c\fR
set suspend process character to \fIc\fR (default control Z).
.br
.ns
.TP 10
.BI dsusp \ c\fR
set delayed suspend process character to \fIc\fR (default control Y).
.br
.ns
.TP 10
.BI rprnt \ c\fR
set reprint line character to \fIc\fR (default control R).
.br
.ns
.TP 10
.BI flush \ c\fR
set flush output character to \fIc\fR (default control O).
.br
.ns
.TP 10
.BI werase \ c\fR
set word erase character to \fIc\fR (default control W).
.br
.ns
.TP 10
.BI lnext \ c\fR
set literal next character to \fIc\fR (default control V).
.PP
.B Modem Control Status:
.sp
These display the current state of modem control.
They are only displayed for actual tty lines and not for pseudo tty
lines (more precisely, it is only displayed for lines which support
the TIOCMGET ioctl.  See tty(4).
.br
.ns
While it is possible to change the state of the modem control lines,
the hardware or other software may prevent the change from actually
taking place,
or may cause the state to immediately revert to the original state.
.TP 15
\fBdcd\fP (\fB\-dcd\fP)
State of Data Carrier Detect.
.TP 15
\fBdsr\fP (\fB\-dsr\fP)
State of Data Set Ready.
.TP 15
\fBdtr\fP (\fB\-dtr\fP)
State of Data Terminal Ready.
.TP 15
\fBcts\fP (\fB\-cts\fP)
State of Clear To Send.
.TP 15
\fBrts\fP (\fB\-rts\fP)
State of Request To Send.
.SH "SEE ALSO"
ioctl(2), tabs(1), tset(1), tty(4)