looking for connection dialogue script language

[Steve Summit]

I'm writing a general interconnection utility, for connecting
things like ttys, ptys, files, and network connections together,
in much the same way that cu or tip (or any modem program)
connects two terminals together, or telnet connects a terminal
and a network connection.  This tool is intended for batch,
rather than interactive use; in particular it will not require
that its controlling end be a terminal (as, for instance, telnet
seems to).

An essential feature of such a tool is a little script language
to direct its interactions with the "other end" when automated
negotiation of some kind of prompt/response sequence is needed.
This sort of thing has been developed many times, of course; one
early example is the uucp expect/send login protocols encoded in
the L.sys file.  I have also heard these protocols referred to as
"chat" scripts.

So I'm posting (to an odd hodgepodge of groups, I'll admit) to
ask for your suggestions on connection protocol languages to
borrow from, build on, or copy outright.  Are there any in such
widespread use as to be considered de facto standards?  Since
I've never actually used any of these packages (why, you might
well ask, am I then trying to write one), I'd also appreciate
pointers to documentation, since a statement that "blither is the
script language to use" does me no good since I won't know
anything about blither.

Please reply by mail.  (Of course, I'll be glad to summarize if
there is anyone else interested in this who doesn't already know
all about it.)

                                            Steve Summit
                                            scs at adam.mit.edu