*BSD News Article 33291


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From: sef@kithrup.com (Sean Eric Fagan)
Subject: Re: Anyone ever add a proc fs to BSD?
Organization: Kithrup Enterprises, Ltd.
Message-ID: <CtKA03.Fw7@kithrup.com>
References: <313e26$rau@ccnet.ccnet.com> <michaelv.775244290@ponderous.cc.iastate.edu>
Date: Tue, 26 Jul 1994 18:57:38 GMT
Lines: 19

In article <michaelv.775244290@ponderous.cc.iastate.edu>,
Michael L. VanLoon <michaelv@iastate.edu> wrote:
>Your subject line is sort of misleading, since both NetBSD and FreeBSD
>have had a /proc fs for quite some time.  I don't know if BSDI has
>ever added one to their product.

4.4BSD has a /proc (I cowrote it).  It works, for examing processes.  It
does not yet work for debugging -- I got the basics of that working (but
didn't send it in to CSRG), but never got the debugger-end working.

Making it work from the kernel point of view is pretty easy, I think; a lot
of the groundwork is there already, and it just needs the addition of one
function and three lines of code wherever one might want to have a process
stop for an event (signal, syscall entry/exit, etc.).  The debugger end of
it is harder -- I never did get around to writing a ptrace emulation
package, and it is *not* a SysVr4-style /proc, so code would need to be
rewritten.  (But, mind you, I think it's a better paradigm than the SysVr4
version...)