[TUHS] Re: After 50 years, what has the Impact of Unix been?

["John Levine" <johnl@taugh.com>]

It appears that Marc Donner <marc.donner@gmail.com> said:
>With the notion of pipes it became possible to operate on data quickly and
>flexibly.  There was nothing new from a fundamental capability point of
>view, but the ease with which one could construct pipelines enabled rapid
>experimentation and encouraged the development of pipe-able components to
>add to the tool set.

Pipes were invented at least three times I'm aware of, but what made them
work so well in Unix is that they looked to the program the same as a file
so any program could use them for input or output without special arrangements,
and the shell made it easy to start two programs and pipe them together.

The Dartmouth Time-Sharing System in the late 1960s had communication files
which were essentially two-way pipes, but they were asymmetrical. One end, the
slave end, looked like a file, but the other end, the master end, was different
and the program had to know it was a com file. They were mostly used to pass
terminal I/O between user programs at the slave end and SIMON at the master end,
the terminal monitor that talked to the front end computer than ran the TTYs.

They were invented again at IBM in the 1970s and described in this paper.  I wrote
them a letter, which they published, saying that Unix pipes did the same thing.

https://dl.acm.org/doi/10.1147/sj.174.0383

R's,
John