BSD

stty

set the options for a terminal device interface

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

Sets or displays on terminal characteristics for the device that is its standard input.

Editor note: Many of these apply to terminals remotely connected serial communication lines and are not applicatable to console.
Most interesting operatnds which do apply to CONSOLE are:
isig, noflsh, size, rows, cols

`isig -isig`	Enable (disable)generating `signals` if input contains special control characters usual keystrokes: `INTR (^?), QUIT (^U), STATUS (^T) and SUSP (^C)`.
`noflsh -noflsh`	disable (enable) flush of pending output after `INTR, QUIT, or SUSP`.
`tostop -tostop`	do not send `SIGTTOU` for background output, causes background jobs to stop if they attempt terminal output.
`oxtabs -oxtabs`	do not expand) tabs to spaces on output.

If no options or operands reports the settings of a subset of characteristics as well as additional ones if they differ from their default values.

speed 9600 baud;
lflags: echoe echoke echoctl pendin
oflags: -oxtabs
cflags: cs8 -parenb

-a Display all the current settings for the terminal to standard output as per IEEE Std 1003.2 POSIX.2) stty all|everything Reports all the terminal modes as with stty -a, except that the control characters are printed in a columnar format.

 speed 9600 baud; 30 rows; 110 columns;
lflags: icanon isig iexten echo echoe -echok echoke -echonl echoctl
        -echoprt -altwerase -noflsh -tostop -flusho pendin -nokerninfo -extproc
iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -iutf8
        -ignbrk brkint -inpck -ignpar -parmrk
oflags: opost onlcr -oxtabs -onocr -onlret
cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow -dtrflow -mdmbuf
cchars: eof = ^D; 
        intr = ^C; kill^†= ^U; quit = ^\; 
        min = 1; reprint = ^R; status = ^T;
        stop = ^S; start = ^Q; discard = ^O; susp = ^Z; dsusp = ^Y;
         time = 0; 
        lnext = ^V; erase = ^?; werase = ^W; eol = ; eol2 = ;

-e Display all the current settings for the terminal to standard output in traditional BSD all format.

speed 9600 baud; 30 rows; 110 columns;
lflags: icanon isig iexten echo echoe -echok echoke -echonl echoctl
        -echoprt -altwerase -noflsh -tostop -flusho pendin -nokerninfo -extproc
iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -iutf8
        -ignbrk brkint -inpck -ignpar -parmrk
oflags: opost onlcr -oxtabs -onocr -onlret
cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow -dtrflow -mdmbuf
discard dsusp   eof     eol     eol2    erase   intr    kill^†    lnext   
^O      ^Y      ^D      <undef> <undef> ^?      ^C      ^U      ^V      
min     quit    reprint start   status  stop    susp    time    werase  
1       ^\      ^R      ^Q      ^T      ^S      ^Z      0       ^W

-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 invocation of stty to restore the current terminal state as per IEEE Std 1003.2 POSIX.2

gfmt1:cflag=4b00:iflag=2b02:lflag=200005cb:oflag=3:discard=f:dsusp=19:eof=4:eol=ff
eol2=ff:erase=7f:intr=3:kill=15:lnext=16:min=1:quit=1c:reprint=12:start=11:status=14:stop=13
susp=1a:time=0:werase=17:ispeed=9600:ospeed=9600

Control Modes:

affect hardware characteristics associated with the terminal, corresponds to the c_cflag in the termios structure.

Combination Modes: saved settings Set the current terminal characteristics to the saved settings produced by `-g` .
`clocal -clocal`	a communications line without with modem control.
`cread -cread`	Enable disable the receiver.
`crtscts -crtscts`	Enable disable `RTS/CTS` (Request To Send / Clear To Send) flow control. (video terminals and emulators usually do not need flow control).
`cs5 cs6 cs7 cs8`	character size in bits (`cs7 \| cs8` most common).
`cstopb -cstopb`	two one stop bits per character. (usually 1)
`hupcl -hupcl`	stop do not stop asserting modem control on last close.
`hup -hup`

`nnnn`	baud rate `nnnn.` If 0, modem control is no longer asserted.
`ospeed nnnn`	output baud rate. If 0, modem control is not asserted.
`ispeed nnnn`	input baud rate . If 0, the input baud rate is set to the value of the output baud rate.
`speed nnnn`	Sets both `ispeed` and `ospeed` to `nnnn`. Examples `1200, 2400, 4800, 9600, 14400, 28800 or 57600`

`pass8`	no `parity & cs8`.
`parenb -parenb`	Enable disable parity generation and detection.
`parity -parity`	parity generation and detection; set `cs7` disable parity generation and detection; set `cs8`.
`evenp`	parity generation and detection and `cs7` (most common).
`-evenp`	`-oddp` and `-parity`.
`-oddp`	`-evenp` and `-parity`.
`parodd -parodd`	odd even parity.
`oddp`	`parenb, cs7`, and `parodd`.
Input Modes: This corresponds to the `c_iflag` in the `termios` structure.
`inpck -inpck`	Enable disable input parity checking.
`parmrk -parmrk`	Mark do not mark characters that have parity errors. Sometimes by highlighting, underscoring or substituting the `SUB` character for the bad character.
`ignpar -ignpar`	Ignore do not ignore characters with parity errors.
`ignbrk -ignbrk`	Ignore do not ignore break on input. `ignbrk` will prevent the sender from requesting purging some previously sent data by sending a break signal.
`brkint -brkint`	Signal do not signal `INTR` to the running process when the system receives a break signal and (usually) purge characters in the output queue. `-brkint` will prevent the receiver from signaling the sender to interrupt processing and (usually) purge characters in the output queue.
`icrnl -icrnl`	Map on input do not map `CR` to `NL`
`inlcr -inlcr`	Map on input do not map `NL` to `CR`
`nl -nl`	Map do not map `cr` to `NL`. `-nl` unsets `inlcr` and `igncr`.
`igncr -igncr`	Ignore do not ignore CR on input. Some senders transmit both `NL & CR` at the end of a line.
`imaxbel -imaxbel`	With `imaxbel` when the input queue maxium has been reached, subsequent input causes the system to insert a `BELL` at the beginning of the output queue (a terminal or simulator will beep) With `-imaxbel` when the input queue maximun is reached, the next input character cause the entire input and output queues to be purged!
`istrip -istrip`	Strip do not strip input characters to seven bits ignoring the high order bit which may be the parity bit.
`iutf8 -iutf8`	input characters are UTF-8 encoded.
`ixoff -ixoff`	receiver transmits does not transmit STOP/START (`X-off/X-on`) when the input queue is nearly full/empty.
`ixon -ixon`	Transmitter turns off when receiving `X-off` and turns on when receiving `X-on` ignores `X-on & X-off`
`ixany -ixany`	Allow any character to restart output.
Output Modes: corresponds to `c_oflag of the termios structure. ( some mechanical terminals, without buffering cannot perform so movements fast enough)`
`bs0 bs1`	style of delay for backspaces (e.g., set BSDLY to BS0)
`cr0 cr1 cr2 cr3`	style of delay for carriage returns (e.g., set CRDLY to CR0)
`ff0 ff1`	style of delay for form feeds (e.g., set FFDLY to FF0)
`nl0 nl1`	style of delay for newlines (e.g., set NLDLY to NL0)
`tab0 tab1 tab2 tab3`	style of delay for horizontal tabs (e.g., set TABDLY to TAB0)
`tabs -tabs`	Same as tab0 (tab3)
`vt0 vt1`	style of delay for vertical tabs (e.g., set VTDLY to VT0)

`ofill -ofill`	Use fill (x'00') characters (use timing) for delays.
`ofdel -odell`	Use DELs (NULs) as fill characters.
`ocrnl -ocrnl`	Map do not map) `CR` to `nl` on output.
`onlcr -onlcr`	Map do not map) NL to `CR-NL output.`
`onlret -onlret`	On the terminal, `NL` performs (does not perform) the `CR` function.
`onocr -onocr`	Do not (do) output CRs at column zero.
`opost -opost`	Post-process output do not post-process output; ignore all other output modes)
`oxtabs -oxtabs`	Expand do not expand) tabs to spaces on output. Local Modes: Local mode flags (lflags) affect various characteristics of terminal processing. interpretation of the 'l' in lflag is ``line discipline flag'', which corresponds to the c_lflag of the termios structure.
`-echo echo`	do not echo back do echo every character typed. Terminals in local mode have displayed the characters themselves..
`echok -echok`	Echo do not echo) NL after KILL character.
`echonl -echonl`	Echo do not echo) NL, even if echo is disabled. Some terminals position the "carriage" at position zero after a RETURN, but do not advance to the next line.
`echoctl -echoctl`	If set, echo control characters as ^X. Otherwise, control characters echo as themselves.
`ctlecho -ctlecho`	Same as echoctl.
`echoe -echoe`	The ERASE character shall (shall not) visually erase the last character
`crtbs -crtbs`	Same as echoe.
`crterase -crterase`	Same as echoe.
`echoke -echoke`	The KILL character shall (shall not) visually erase the current line
`crtkill -crtkill`	Same as echoke.
`echoprt -echoprt`	For printing terminals. echo erased characters backwards within ``\'' and ``/''. Otherwise, disable this feature.
`flusho -flusho`	Indicates output is (is not) being discarded.
`icanon -icanon`	Enable disable canonical input (ERASE and KILL processing)
`iexten -iexten`	Enable disable any implementation-defined special control characters that are not currently controlled by icanon, isig, ixoff, or ixon.
`isig -isig`	Enable disable the checking of input for the special control characters INTR, QUIT, and SUSP.
`noflsh -noflsh`	disable (enable) flush after INTR, QUIT, or 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. which considers 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.)
`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 disable d (i.e. set to {_POSIX_Vdisable }. control- control- character Subscript Description character Subscript Description _________ _________ _______________ _________ _________ _______________ eof VEOF EndOfFile eol VEOL EndOfLine eol2 VEOL2 EOL2 erase VERASE ERASE erase2 VERASE2 ERASE2 werase VWERASE WERASE intr VINTR INTRupt kill VKILL KILL quit VQUIT QUIT susp VSUSP SUSPend start VSTART START stop VSTOP STOP dsusp VDSUSP DSUSP lnext VLNEXT LNEXT reprint VREPRINT REPRINT status VSTATUS STATUS
`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 .
`cols number`	Same as columns.
`columns number`	The terminal size is recorded as having number columns.
`crt -crt`	Set disable all modes suitable for a CRT display device.
`newcrt -newcrt`	Same as crt.
`dec`	Set modes suitable for users of Digital Equipment Corporation systems (ERASE, KILL, and INTR are set to ^?, ^U, and ^C; ixany is disable d, and crt is enabled.)
`ek`	Reset ERASE, ERASE2, and KILL back to system defaults.
`extproc -extproc`	terminal processing is being performed by either the terminal hardware or by the remote side connected to a pty.
`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. `load: 3.64 cmd: bash 12892 waiting 0.00u 0.01s` waiting or running or uninterruptible
`raw -raw`	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. unsetting raw may not put back all the setting that were previously in effect. To set the terminal into a raw state and then restore it save_state=$(stty -g) stty raw ... stty "$save_state"
`rows number`	The terminal size is recorded as having number rows.
`sane`	sets all modes to reasonable values
`cooked`	Same as sane.
`size`	window size is displayed rows columns.
`tty`	Set the line discipline to the standard terminal line discipline TTYDISC.
`new`	Same as tty.
`old`	Same as tty.
`brk value`	Same as the control character eol.
`cbreak`	If set, enables brkint, ixon, imaxbel, opost, isig, iexten, and -icanon. If unset, same as sane.
`decctlq -decctlq`	The converse of ixany.
`flush value`	Same as the control character discard.
`litout -litout`	The converse of opost.
`prterase -prterase`	Same as echoprt.
`rprnt value`	Same as the control character reprint.
`tabs -tabs`	The converse of oxtabs.
`tandem -tandem`	Same as ixoff.

DIAGNOSTICS exits 0 on success, and >0 if an error occurs. LEGACY DESCRIPTION In legacy operation, the bs[01], cr[0-3], ff[01], nl[01], tab[0-3], and vt[01] control modes are not accepted, nor are ocrnl
-ocrnl , ofdel (-ofdel) ofill (-ofill) onlret (-onlret) and onocr
-onocr . SEE ALSO termios(4) compat(5)

stty

set the options for a terminal device interface

Control Modes:

Input Modes:

Output Modes: