[TUHS] sockets (was Re: First appearance of named pipes)

George Michaelson ggm at algebras.org
Thu Mar 26 13:43:01 AEST 2020

Options negotiation and the URG/PUSH always freaked me out. PAD (the
X.25 equivalent) was a bugger to work with. From memory, the yorkbox
was a forked pair of processes one to read, one to write. it didn't
work very well to be honest. I tended to convert to half-duplex mode
and construct valid lines of input before sending them (which is not
very editor friendly unelss you like Teco, which I didn't since it was
complicated. I stuck to SOS and ed)

Telnet is pretty much just "read and write for networks" except for
the options. Back in the days of the BBN Butterfly, the gethostaddr()
table for de interwebz was a linear list, and UCL was at the back of
the hosts.txt sort and the time it took the daemon to work out who we
were, for a login: prompt, was 1-2 sec close to the 30 second
drop-link-he's-dead-jim timer in getty or whatever it was then. Sad. I
think we made a lot of drama about read and write for networks.
Really, asynchronous communicating processes is a lot of fun. I went
to Milners lectures on the calculus of communicating systems, it was
also too hard, I lost it.

That was also when the real underlying routing (pre BGP) was a
push-down list, which dropped our routes because we were the boring
british side of things and LRU cache said no.  Rebooting the right
fuzzball or BBN box generall brought it back.

X25 was a good fit for PAD. small packets. Enter the ATM cell size
discussion <----here.

On Thu, Mar 26, 2020 at 1:09 PM Rob Pike <robpike at gmail.com> wrote:
> I can't find it now, but there's a very short rc script that does a
> modestly realistic telnet client in Plan 9.
> But you know, that's not Unix.
> -rob
> On Thu, Mar 26, 2020 at 1:39 PM Dave Horsfall <dave at horsfall.org> wrote:
> >
> > On Wed, 25 Mar 2020, Grant Taylor via TUHS wrote:
> >
> > > · netcat's STDOUT to grep's STDIN
> > > · grep's STDOUT to netcat's STDIN
> >
> > Are you trying to set up a loop of processes or something?  I'm not sure
> > if that is even possible, although you can't rule out creative uses of
> > dup2() etc...
> >
> > -- Dave

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