Pseudo terminals (PTYs) are available in Ironclad, They are created using
see openpty. Ironclad does not provide a /dev/ptmx like interface.
PTYs populate /dev with names of the form /dev/ptyX, where X is
a positive integer. PTYs are closed automatically when they are closed.
PTYs react to a limited amount of termios flags, most of them left to userland.
The ones Ironclad PTYs interact with are OPOST and ONLCR.