TTY(1)

NAME

tty — get path to current teletype

SYNOPSIS

tty [-s]

DESCRIPTION

Write the path of the tty connected to the standard input stream, or "not a tty", followed by a newline, to the standard output stream, and exit successfully only if it is.

OPTIONS

-s, --silent, --quiet: Don't write anything, use isatty(3).

EXIT STATUS

2: an error occurred,
1: the standard input stream is not attached to a teletype (or its name is undeterminable), and
0: otherwise.

STANDARDS

Conforms to IEEE Std 1003.1-2008 (“POSIX.1”). The long flags are an extension, originating from the GNU system.

IEEE Std 1003.2-1992 (“POSIX.2”) specifies -s, but notes it as obsolescent, pointing toward the use of test -t 0 instead. IEEE Std 1003.1-2001 (“POSIX.1”) removes it.

HISTORY

Appears in the first edition of the UNIX Programmer's Manual as

tty  --  get tty
  name

writing "ttyn" or "not a tty" if the standard input file is not a typewriter (actually "Not a tty.").

Version 7 AT&T UNIX introduced -s, initially undocumented, and switched to the new ttyname(3) function, arriving at the tty of today.