TTY (1) | General commands | Unix Manual Pages | :man▋
tty - return users terminal name
The 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:
|-s || Do not 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. |
The tty utility exits 0 if the standard input is a terminal, 1 if the standard input is not a terminal, and >1 if an error occurs.