Terminal.app and other terminal emulators are the prototypical case where a TTY -- more precisely, a TTY/PTY pair -- are required these days.
Every virtual terminal in the Linux text-mode console also requires a TTY/PTY pair.
Shell mode (and more generally any mode derived from Comint mode) in Emacs also requires a TTY/PTY pair: although the Emacs documentation claims that Comint-derived modes can be configured to use a pipe instead, a comment in comint.el confesses that no one has gotten that to actually work.
And of course, SSHing into a remote host requires at least one TTY/PTY pair (on the remote host).
Are there other place in the software on, e.g., a Mac reliant on a TTY? If there are, please tell me what they are!
Both `ssh` and `sudo` will only ask you for a password from a TTY; they'll refuse to work if they can't find a TTY (unless, of course you have a graphical prompt configured).
The `expect` suite of tools uses a TTY/PTY pair to script programs that might otherwise be unhappy with not having a PTY. Same with the `script` program, which on my system is part of the 'util-linux' package.
On GNU/Linux, `systemd-nspawn` (a chroot-like tool) uses a TTY/PTY pair to isolate the child process from the outside world.
Every virtual terminal in the Linux text-mode console also requires a TTY/PTY pair.
Shell mode (and more generally any mode derived from Comint mode) in Emacs also requires a TTY/PTY pair: although the Emacs documentation claims that Comint-derived modes can be configured to use a pipe instead, a comment in comint.el confesses that no one has gotten that to actually work.
And of course, SSHing into a remote host requires at least one TTY/PTY pair (on the remote host).
Are there other place in the software on, e.g., a Mac reliant on a TTY? If there are, please tell me what they are!