tty Command Cheat Sheet

SSH: When you SSH in, you are assigned a pseudo-terminal ( /dev/pts/N ).
Console: Physical console is usually /dev/tty1 .

tty prints the file name of the terminal connected to standard input.

Synopsis

tty [OPTION]...

tty
# Output: /dev/pts/0

If run from a script without a terminal (e.g., cron):

tty
# Output: not a tty

Do not print anything, just return an exit status. - 0: Standard input is a terminal. - 1: Standard input is NOT a terminal.

if tty -s; then
    echo "Running interactively"
else
    echo "Running in background/script"
fi