Peter Weinberger started and Tom Killian finalized a version of /proc for
the eighth edition that is ioctl-driven. It was done in the early 1980s. I
don't know where the idea originated.

In Plan 9, we (I?) replaced the ioctl interface, which was offensively
non-portable.

-rob


On Wed, Jun 26, 2019 at 10:01 AM ron minnich <rminnich@gmail.com> wrote:

> On Tue, Jun 25, 2019 at 12:34 PM Norman Wilson <norman@oclsc.org> wrote:
> >
> > It's interesting that this comment about ptrace was written
> > as early as 1980.
> >
> > Ron Minnich's reference to Plan 9 /proc misses the mark, though.
>
> your comment about my comment misses the mark; I was not talking about
> the origins of /proc. This is probably because I was not clear and
> probably because few people realize that the plan 9 process debugging
> interface was strings written and read to/from /proc/<pid>/[various
> files], rather than something like ptrace.
>
> The first time I saw that debug-interface-in-proc in plan 9, it made
> me think back to the 4.1c bsd manual ptrace comment, and I wondered if
> there was any path that led from this man page entry to the ideas in
> the plan 9 methods.
>
> I actually implemented the plan 9 debug model in linux back around
> 2007, but was pretty sure getting it upstream would never happen, so
> let it die.
>
> ron
>