NAME
     tty - return user's terminal name

SYNOPSIS
     tty [-s]

DESCRIPTION
     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 written.  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.

     Tty 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 function is expected to be IEEE Std1003.2 (``POSIX'') compatible.