The pty program is a persistent remote shell, similar to screen and tmux but focused on the usage ssh -t host pty.
A single pty session is a single shell. When starting up pty it lists all known sessions so you can either connect to an existing
session or start up a new session. Multiple clients can connect to the same session. It maintains both the regular and auxiliary
screens so when you connect you can still scroll back through old content. It also can forward sockets, such as SSH_AUTH_SOCK.
The escape character is ^P so it won't interfere with SSH's ~. Originally written to enable easy transition from working in
the office to working at home on Google's corporate network.