CHAPTER 3 Getting Started

3.4 stty - terminal control

For new users, the most important use of the stty command is setting the erase function to the appropriate key on their terminal. For systems programmers or shell script writers, the stty command provides an invaluable tool for configuring many aspects of I/O control for a given device, including the following:

- erase and line-kill characters

- data transmission speed

- parity checking on data transmission

- hardware flow control

- newline (NL) versus carriage return plus linefeed (CR-LF)

- interpreting tab characters

- edited versus raw input

- mapping of upper case to lower case

This command is very system specific, so consult the man pages for the details of the stty command on your system.

Syntax

stty [options]

Options

(none) report the terminal settings

all (or -a) report on all options

echoe echo ERASE as BS-space-BS

dec set modes suitable for Digital Equipment Corporation operating systems (which distinguishes between ERASE and BACKSPACE) (Not available on all systems)

kill set the LINE-KILL character

erase set the ERASE character

intr set the INTERRUPT character

Examples

You can display and change your terminal control settings with the stty command. To display all (-a) of the current line settings:

% stty -a

speed 38400 baud, 24 rows, 80 columns

parenb -parodd cs7 -cstopb -hupcl cread -clocal -crtscts

-ignbrk brkint ignpar -parmrk -inpck istrip -inlcr -igncr icrnl -iuclc

ixon -ixany -ixoff imaxbel

isig iexten icanon -xcase echo echoe echok -echonl -noflsh -tostop

echoctl -echoprt echoke

opost -olcuc onlcr -ocrnl -onocr -onlret -ofill -ofdel

erase kill werase rprnt flush lnext susp intr quit stop eof

^H ^U ^W ^R ^O ^V ^Z/^Y ^C ^\ ^S/^Q ^D

You can change settings using stty, e.g., to change the erase character from ^? (the delete key) to ^H:

% stty erase ^H

This will set the terminal options for the current session only. To have this done for you automatically each time you login, it can be inserted into the .login or .profile file that we'll look at later.