tty

Print file name of terminal on standard input, print the file name of the terminal connected to standard input. It prints `not a tty' if standard input is not a terminal.

SYNTAX
      tty [OPTION]...

OPTION

   -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

"Behind every great fortune there is a crime" - Honore de Balzac

Related commands:

env - Display, set, or remove environment variables
hostname - Print or set system name
id - Print user and group id's
logname - Print current login name
uname - Print system information
users - Print login names of users currently logged in
who - Print who is currently logged in
whoami - Print the current user id and name (`id -un')