return user's terminal name
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:
- 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”
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
tty utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
tty command appeared in
Version 1 AT&T UNIX.