@b0rk @njvack Oh yeah, you also needed ptys for telnet/rlogin/ssh-like services. And the tty driver was already hellishly complex even before GUIs entered the picture. Tons of respect to anyone who unpeels the onion in the modern era - so many moving parts.
Gregory's Server
@b0rk @njvack One other thing that was an A-ha! moment for me back in the day was learning that stty uses an ioctl() to determine the tty behind stdin, so you can redirect from another tty (assuming you have permission) to see its settings. So, assuming /dev/ttys000 is a different window, I can 'stty -a < /dev/ttys000' and see how the flags change between cat, bash, and vim for example.