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

[George Michaelson <ggm@algebras.org>]

The lack of consistency in what you can READ in /proc makes it hard to
believe its useful in the "wide" -but I am sure specific things get
benefit from it, as an abstraction which makes code simple because
"its a file"

if you're WRITING into things in /proc, I think you own the pain be it
an ioctl() or anything else.

I see occasional shell scripts about turning on and off meta-state for
SCSI or SAS as "cat 0 >
/dev/somedir/some-model-of-abstraction/some-disk" and while I applaud,
I also wince. So easy to go wrong..

As a long-term user and non-developer, I'm sort of half a believer,
half not. Maybe if it had emerged before the great Schism(s) it would
be more normal? sane? understandable?

-G

On Wed, Jun 26, 2019 at 11:04 AM ron minnich <rminnich@gmail.com> wrote:
>
> On Tue, Jun 25, 2019 at 5:46 PM Larry McVoy <lm@mcvoy.com> wrote:
> >
> > 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.
>
> it's very handy but quite difficult to work with programatically. The
> output is convenient for humans to parse, not very nice for programs
> to parse.
>
> /proc on linux has no real standard way of outputting things. You get
> tables, tuples, and lists and some stuff I can't classify
> (/proc/execdomains, /proc/devices); and, in some cases, some files
> give you more than one type of thing. Units are not clear for many
> tables.
>
> /proc on linux has far more than just process information, including
> stuff that has nothing to do with processes (51 things on my current
> linux, e.g. /proc/mounts).
>
> Things are in many cases not self-describing, though lots of /proc
> have this issue.
>
> I do recall (possibly wrongly) at some point in the 2000s there was an
> effort to stop putting stuff in /proc, but rather in /sys, but that
> seems to have not worked out. /proc is just too convenient a place,
> and by convention, lots of stuff lands there.
>
> While I was at LANL we did experiment with having /proc come out as
> s-expressions, which were nicely self describing, composable, easily
> parsed and operated on, and almost universally disliked b/c humans
> don't read s-expressions that easily. So that ended.
>
> We've been reimplementing Unix commands in Go for about 8 years now
> and dealing with all the variance in /proc on linux was a headache.
> You pretty much need a different function for every file in /proc.
>
> And all that said, it's handy, so hard to complain about too much.