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From: "John Levine" <johnl@taugh.com>
To: tuhs@tuhs.org
Cc: mrochkind@gmail.com
Subject: [TUHS] Re: Pipes (was Re: After 50 years, what has the Impact of Unix been?)
Date: 5 Dec 2024 13:05:41 -0500	[thread overview]
Message-ID: <20241205180541.E2818AB56024@ary.qy> (raw)
In-Reply-To: <CAOkr1zV7goW0H3WwtCquuTLCWs4m=aEp8HR0hnKUJMjkMH_Juw@mail.gmail.com>

It appears that Marc Rochkind <mrochkind@gmail.com> said:
>-=-=-=-=-=-
>-=-=-=-=-=-
>
>I don't think files as pipes would be "transparent to the user." Reading an
>empty pipe causes a wait until the bytes requested are available, unless
>the pipe is closed first. ...

You should read Meinz' paper.  This was a cut down version of Unix that ran
in 40K bytes on an LSI-11 with a couple of floppy disks.  It ran one program
at a time, since swapping to floppies was absurdly slow.  The pseudo-pipe
ran the first program which wrote the output to a file, then ran the second
program which read it.  It was close enough for most purposes so long as
the disk didn't fill up.

>Still, the same sort of pseudo-pipes were in MS-DOS, and they were
>occasionally useful.

I can think of lots of places that had a way for one program to write a temporary
file that a subsequent one read.  For example, in OS/360 JCL you'd write (well, punch)
something like this for the object output of the Fortran compiler

//SYSLIN DD DSNAME=&OBJECT,DISP=(NEW,PASS),UNIT=SYSSQ

and then in the linker read it in

//SYSIN DD DSNAME=&OBJECT,DISP=(OLD,DELETE)

The & in the name said it was a temp file so make up a unique name.  I probably didn't
get the JCL exactly right since it's been about 50 years since I wrote any.

R's,
John

  parent reply	other threads:[~2024-12-05 18:05 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
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 [this message]
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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