solaris - tty (1)

     tty - return user's terminal name

     tty [ -l ] [ -s ]

     SUNWcsu

     The tty utility writes to the standard output  the  name  of
     the  terminal that is open as standard input.  The name that
     is used is equivalent to the string that would  be  returned
     by the ttyname(3C) function.

     The following options are supported:

     -l         Prints the synchronous line number to  which  the
               user's  terminal  is  connected,  if  it  is on an
               active synchronous line.

     -s         Inhibits printing  of  the  terminal  path  name,
               allowing one to test just the exit status.

     See environ(5) for descriptions of the following environment
     variables  that  affect  the  execution  of  tty:  LC_CTYPE,
     LC_MESSAGES, and NLSPATH.

     The following exit values are returned:

     0   Standard input is a terminal.

     1   Standard input is not a terminal.

     >1  An error occurred.

     isatty(3C), ttyname(3C), environ(5)

     not on an active synchronous line
                    The standard input is not a synchronous  ter-
                    minal and -l is specified.

     not a tty      The standard input is not a terminal and  - s
                    is not specified.

     The -s option is useful only if the exit status  is  wanted.
     It  does  not rely on the ability to form a valid path name.
     Portable applications should use test -t.