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From: "John R Levine" <johnl@taugh.com>
To: "Dan Cross" <crossd@gmail.com>
Cc: TUHS <tuhs@tuhs.org>, Marc Donner <marc.donner@gmail.com>
Subject: [TUHS] Re: Pipes (was Re: After 50 years, what has the Impact of Unix been?)
Date: 5 Dec 2024 11:00:40 -0500	[thread overview]
Message-ID: <32bf4263-277d-8c8b-6bf7-e33df04a2c3c@taugh.com> (raw)
In-Reply-To: <CAEoi9W4Qyn4A=SQb9-_uOPR=K8mriFUqmwU9YQoy2-Kekb0VnQ@mail.gmail.com>

On Thu, 5 Dec 2024, Dan Cross wrote:
>> 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.
>
> Once you have coroutines and queues for passing data between them, a
> lot of things start to look like pipes.

They also can look a lot like temporary files.  Someone, probably Heinz, 
did a shell for the tiny Unix that ran on floppies so this

  foo | bar

actually did this

  foo > tmpfile ; bar < tmpfile; rm tmpfile

to avoid having to swap programs in and out on floppies.  The main 
disadvantage was that the tmpfile could overflow the tiny disks of the 
time.

>> 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
>
> Don't forget CMS pipelines, too!
>
> Sadly, the Morrison paper cited above is not easily accessible, though

If anyone else needs a copy, just ask.

Regards,
John Levine, johnl@taugh.com, Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail. https://jl.ly

  reply	other threads:[~2024-12-05 16:00 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-04  3:17 [TUHS] After 50 years, what has the Impact of Unix been? sjenkin
2024-12-04 13:05 ` [TUHS] " Marc Donner
2024-12-04 13:40   ` William Cheswick
2024-12-04 15:02   ` Rich Salz
2024-12-05  3:08   ` John Levine
2024-12-05 15:19     ` [TUHS] Re: Pipes (was Re: After 50 years, what has the Impact of Unix been?) Dan Cross
2024-12-05 16:00       ` John R Levine [this message]
2024-12-05 16:17         ` Heinz Lycklama
2024-12-05 17:06           ` Marc Rochkind
2024-12-05 17:53             ` John Cowan
2024-12-05 18:05             ` John Levine
2024-12-05 17:22           ` Paul Winalski
2024-12-05 18:19         ` Ron Natalie
2024-12-06  2:29           ` Adam Thornton
2024-12-07 20:38             ` Ron Natalie
2024-12-05 16:55       ` Adam Thornton
2024-12-05 17:35       ` Chet Ramey via TUHS
2024-12-05 20:55         ` arnold
2024-12-05 21:12           ` Dan Cross
2024-12-05 21:50             ` Marc Rochkind
2024-12-05 22:03             ` Warner Losh
2024-12-05 22:19               ` Chet Ramey via TUHS
2024-12-05 23:07                 ` Marc Rochkind
2024-12-06  8:16                   ` Diomidis Spinellis
2024-12-06  0:46                 ` Alexis
2024-12-06 21:46                   ` Chet Ramey via TUHS
2024-12-05 23:07               ` arnold
2024-12-06  1:09                 ` G. Branden Robinson
2024-12-06  1:31                   ` Greg A. Woods
2024-12-06  2:05                     ` Steve Nickolas
2024-12-06 16:44                     ` arnold
2024-12-05 22:05             ` Bakul Shah via TUHS
2024-12-06  2:02             ` John Levine
2024-12-06  2:21               ` Dan Cross
2024-12-06 16:46                 ` arnold
2024-12-06  2:26 Douglas McIlroy

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