Re: [TUHS] 4.1c bsd ptrace man entry ("ptrace is unique and arcane")

[Larry McVoy <lm@mcvoy.com>]

I'm curious what Rob and others think of the Linux /proc.  It's string 
based and it seems like it is more like /whatever_you_might_want.

The AT&T /proc that Faulkner worked on was much more narrow in scope,
in keeping with the Unix tradition.  The linux /proc was both a way
to dig into kernel stuff and control kernel stuff, it was way broader.

On Wed, Jun 26, 2019 at 10:37:39AM +1000, Rob Pike wrote:
> 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
> >

-- 
---
Larry McVoy            	     lm at mcvoy.com             http://www.mcvoy.com/lm