NAME

tty − Returns pathname of terminal device

SYNOPSIS

tty [-s]

The tty command writes the full pathname of your terminal device to standard output. 

DESCRIPTION

tty -s evaluates as TRUE if standard output is a display and FALSE if it is not. 

/dev/tty is a special file always refers to your controlling terminal, although it also may have another name like /dev/console or /dev/tty2.  To avoid writing undesirable output to an output file -- for example, to write a prompt in a shell script to the screen, while writing the response to the prompt to an output file -- redirect standard output to /dev/tty. 

FLAGS

-sSuppresses reporting the pathname. 

EXAMPLES

     1.To display full pathname of your terminal device, enter:

tty

     2.To test whether or not the standard input is a terminal device, create a shell script containing the following:

if tty -s
then
echo ’Output is a display’
else
echo ’Output is not a display’
fi

If the standard input is a terminal device, this displays the Output is a display message.  If the standard input is not a terminal device, it displays the Output is not a display message. 

DIAGNOSTICS

Standard input is not a tty
Your standard input is not a display and you did not specify the -s flag. 

EXIT VALUES

The exit value has the following possible meanings:

0Standard output is a display. 

1Standard input is not a display. 

2Invalid flags specified. 

FILES

/dev/ttyPseudodevice representing the user’s controlling terminal. 

RELATED INFORMATION

Commands:  stty(1). 

Files:  tty(7).