The "svc-t" program / "x.svc.t"
 permission makes up the terminal
 subsystem for KittenOS NEO.

 --- THEORETICAL TERMINALS MODEL ---

The theoretical model for terminals
 in KittenOS NEO is that of a stack
 of processes controlling a player's
 connection to a MUD, where text is
 provided to the server and to the
 player in a line-by-line format,
 with no "flow control"/ttyattrs.

A process starting another process
 connected to the same terminal is
 advised to wait for that process to
 die before continuing in terminal
 activities, unless some sort of
 'in-band notification' functionality
 is intended.

The controlling process is whichever
 process is supposed to be accepting
 user input. This is contextual, and
 there is no mechanism to control
 this explicitly.

The controlling process should show
 text in response to any user input,
 or at least provide some form of
 acknowledgement that user input has
 been received.

User input IS NOT automatically
 echoed by the terminal.

  --- ACTUAL USAGE OF TERMINALS ---

Access control on terminals is looser
 than for most permissions, as it has
 to be able to be 'sublet' in some
 cases, including events.

A terminal program is given a string
 argument for the ID of the terminal
 to connect to.

A terminal always has an ID beginning
 with "x.svc.t/". ALWAYS CHECK THIS.

Requiring the responsible access
 connects to the terminal. All
 terminal programs SHOULD check for
 the death of their parent terminal
 (via the k.procdie event) and
 self-destruct accordingly.

A program may start svc-t directly.

In this case, it must pass a function
 (resTbl) and may pass a title.

When the terminal has shown, the
 function provided is called with a
 table as follows:

access = "x.svc.t/<...>"
close = function (): close terminal

The k.kill permission and the close
 function are the only ways for a
 program to kill a terminal, and the
 close function is only given to the
 creating process.

In either case, when the access has
 been acquired, the following API is
 presented:

id = "x.svc.t/<...>"
pid = <The terminal's PID.>
line = function (text): Shows a line.

When the user sends a line, an event
 of: <id>, "line", <text>
 is provided.

-- This is released into
 the public domain.
-- No warranty is provided,
 implied or otherwise.