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* [TUHS] PDP-7 UNIX filesystem
@ 2019-10-21  6:22 Angelo Papenhoff
  2019-10-21 10:43 ` Abhinav Rajagopalan
                   ` (2 more replies)
  0 siblings, 3 replies; 24+ messages in thread
From: Angelo Papenhoff @ 2019-10-21  6:22 UTC (permalink / raw)
  To: tuhs

DMR explained how PDP-7 UNIX was used in "The Evolution of the Unix
Time-sharing System" but having played with it myself, I stumbled in a
couple of cases and found it a bit awkward to use.
Maybe someone (ken and doug?) can shed some light on "elaborate set of
conventions" that dmr mentioned.

My questions are these:


you cannot execute a program if you're in a directory you can't write into.

	I asked Warren about this when I first tried pdp7 unix and he
explained it to me: the shell creates a link to the binary and executes
it. If it can't write into the current directory, it fails to create the
link and hence can't execute the program.
	How was this handled in practice? did users have write
permissions on all directories? did you just stay in your directory all
the time?


. and ..

	Was this introduced first with PDP-11 unix or did the convention
start on the PDP-7 already? It certainly seems to be the case with .
but how about ..? the dd directory seems to take on the role of a sort
of root directory and the now discovered program pd actually creates a
file .. (haven't tried to understand what it does though yet)
What does dd stand for, dotdot? directory directory?


aap

^ permalink raw reply	[flat|nested] 24+ messages in thread
* Re: [TUHS] PDP-7 UNIX filesystem
@ 2019-10-21 11:58 Noel Chiappa
  2019-10-21 15:44 ` Abhinav Rajagopalan
  2019-10-22  2:09 ` Jaap Akkerhuis
  0 siblings, 2 replies; 24+ messages in thread
From: Noel Chiappa @ 2019-10-21 11:58 UTC (permalink / raw)
  To: tuhs; +Cc: jnc

    > From: Abhinav Rajagopalan

    > I only now realized that only mknod existed, up until a long time, only
    > later on with the GNU coreutils did mkdir as a command come into
    > existence.

Huh? See:

    https://minnie.tuhs.org//cgi-bin/utree.pl?file=V6/usr/man/man1/mkdir.1

(And probably before that, that was the quickest one to find?)

Maybe that was a typo for 'mkdir as a system call'? (I recall having to do a
fork() to execute 'mkdir', back when.) But 4.2 had mkdir().

       Noel


^ permalink raw reply	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2019-10-25 22:55 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-21  6:22 [TUHS] PDP-7 UNIX filesystem Angelo Papenhoff
2019-10-21 10:43 ` Abhinav Rajagopalan
2019-10-21 11:38   ` Abhinav Rajagopalan
2019-10-21 12:00     ` Thomas Paulsen
2019-10-21 13:31       ` Abhinav Rajagopalan
2019-10-22 18:07   ` Peter Jeremy
2019-10-23  0:07     ` Mary Ann Horton
2019-10-23  2:02       ` Kurt H Maier
2019-10-23  2:19         ` Larry McVoy
2019-10-23  8:34       ` Thomas Paulsen
2019-10-24  0:06         ` Warner Losh
2019-10-24  2:23           ` Michael Parson
2019-10-25 21:08             ` Michael Kjörling
2019-10-25 21:34               ` Arthur Krewat
2019-10-25 21:50                 ` reed
2019-10-25 22:54                 ` Warner Losh
2019-10-24  2:29   ` Christopher Browne
2019-10-24  8:25     ` Thomas Paulsen
2019-10-21 16:54 ` Angelo Papenhoff
2019-10-23  5:48 ` Lars Brinkhoff
2019-10-21 11:58 Noel Chiappa
2019-10-21 15:44 ` Abhinav Rajagopalan
2019-10-22  2:09 ` Jaap Akkerhuis
2019-10-23  2:00   ` Christopher Browne

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