tty - print the file name of the terminal connected to standard input
Print the file name of the terminal connected to standard input.
print nothing, only return an exit status
display this help and exit
output version information and exit
Written by David MacKenzie.
Copyright © 2020 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
Full documentation <https://www.gnu.org/software/coreutils/tty>
or available locally via: info '(coreutils) tty invocation'