19.4 tty: Print file name of terminal on standard input

tty prints the file name of the terminal connected to its standard input. It prints `not a tty' if standard input is not a terminal. Synopsis:

tty [option]...

The program accepts the following option. Also see 2. Common options.

`-s'

`--silent'

`--quiet'

Print nothing; only return an exit status.

Exit status:

0 if standard input is a terminal 1 if standard input is not a terminal 2 if given incorrect arguments 3 if a write error occurs