MirBSD manpage: tty(1)
TTY(1) BSD Reference Manual TTY(1)
tty - return user's terminal name
tty [-s]
The tty utility writes the name of the terminal attached to standard in-
put to standard output. The name that is written is the string returned
by ttyname(3).
If the standard input is not a terminal, the message "not a tty" is writ-
ten.
The options are as follows:
-s Don't write the terminal name; only the exit status is affected
when this option is specified. The -s option is deprecated in
favor of the "test -t 0" command.
The tty utility exits 0 if the standard input is a terminal, 1 if the
standard input is not a terminal, or >1 if an error occurred.
stty(1), test(1), ttyname(3), tty(4)
The tty utility conforms to IEEE Std 1003.2-1992 ("POSIX.2").
A tty command appeared in Version 1 AT&T UNIX.
MirBSD #10-current June 6, 1993 1