Unknown option: "-4" Unix manual page for tty. (host=minya system=Darwin)
TTY(1)                    BSD General Commands Manual                   TTY(1)

NAME
     tty -- return user's terminal name

SYNOPSIS
     tty [-s]

DESCRIPTION
     The tty utility writes the name of the terminal attached to standard
     input 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 written.  The options are as follows:

     -s      Do not 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.

EXIT STATUS
     The tty utility exits 0 if the standard input is a terminal, 1 if the
     standard input is not a terminal, and >1 if an error occurs.

SEE ALSO
     test(1), ttyname(3)

STANDARDS
     The tty utility is expected to be IEEE Std 1003.2 (``POSIX.2'') compati-
     ble.

HISTORY
     A tty command appeared in Version 1 AT&T UNIX.

BSD                              June 6, 1993                              BSD