From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <tuhs-bounces@minnie.tuhs.org>
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no
	version=3.4.2
Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53])
	by inbox.vuxu.org (OpenSMTPD) with ESMTP id e07c03ce
	for <ml@inbox.vuxu.org>;
	Mon, 13 Jan 2020 22:20:44 +0000 (UTC)
Received: by minnie.tuhs.org (Postfix, from userid 112)
	id 0658F9BD40; Tue, 14 Jan 2020 08:20:43 +1000 (AEST)
Received: from minnie.tuhs.org (localhost [127.0.0.1])
	by minnie.tuhs.org (Postfix) with ESMTP id E64599B841;
	Tue, 14 Jan 2020 08:20:23 +1000 (AEST)
Received: by minnie.tuhs.org (Postfix, from userid 112)
 id CA98B9B841; Tue, 14 Jan 2020 08:20:21 +1000 (AEST)
Received: from mcvoy.com (mcvoy.com [192.169.23.250])
 by minnie.tuhs.org (Postfix) with ESMTPS id 79FD39B804
 for <tuhs@tuhs.org>; Tue, 14 Jan 2020 08:20:21 +1000 (AEST)
Received: by mcvoy.com (Postfix, from userid 3546)
 id 30C3A35E088; Mon, 13 Jan 2020 14:20:21 -0800 (PST)
Date: Mon, 13 Jan 2020 14:20:21 -0800
From: Larry McVoy <lm@mcvoy.com>
To: Rico Pajarola <rp@servium.ch>
Message-ID: <20200113222021.GG8511@mcvoy.com>
References: <CABH=_VTOhJ57t-iWkcV9KYoSmDjy-6-6-sUTVYz-nJDTrprHjw@mail.gmail.com>
 <CACwAiQ=QTRc6OJrGDQ_Jw50sAPUCaTqQq3mJVLJ3GN0K4U=YBw@mail.gmail.com>
 <CAC20D2PsgKMtANSSQ2be4of8VDKCZZ5j7jmQYeGa6N5U532mfA@mail.gmail.com>
 <CACwAiQnGghCWDENNou7+8qndDZC1UfiTHadWKDyt7HcbdH_nYg@mail.gmail.com>
 <CABH=_VQgzhG-dCZbq1ZkwCwMNyxv_LWQSp6ZSjckUbN0FN4=Aw@mail.gmail.com>
 <CACwAiQ=+J2A0GyAKh9ywuHCPbqT0h05HDmttOu5-raLXWJ8ZNw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CACwAiQ=+J2A0GyAKh9ywuHCPbqT0h05HDmttOu5-raLXWJ8ZNw@mail.gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Subject: Re: [TUHS] History of symbol preemption
X-BeenThere: tuhs@minnie.tuhs.org
X-Mailman-Version: 2.1.26
Precedence: list
List-Id: The Unix Heritage Society mailing list <tuhs.minnie.tuhs.org>
List-Unsubscribe: <https://minnie.tuhs.org/cgi-bin/mailman/options/tuhs>,
 <mailto:tuhs-request@minnie.tuhs.org?subject=unsubscribe>
List-Archive: <http://minnie.tuhs.org/pipermail/tuhs/>
List-Post: <mailto:tuhs@minnie.tuhs.org>
List-Help: <mailto:tuhs-request@minnie.tuhs.org?subject=help>
List-Subscribe: <https://minnie.tuhs.org/cgi-bin/mailman/listinfo/tuhs>,
 <mailto:tuhs-request@minnie.tuhs.org?subject=subscribe>
Cc: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Errors-To: tuhs-bounces@minnie.tuhs.org
Sender: "TUHS" <tuhs-bounces@minnie.tuhs.org>

On Mon, Jan 13, 2020 at 01:45:48PM -0800, Rico Pajarola wrote:
> On Mon, Jan 13, 2020 at 1:44 PM Paul Winalski <paul.winalski@gmail.com>
> wrote:
> 
> > On 1/13/20, Rico Pajarola <rp@servium.ch> wrote:
> > >
> > > yes, but unless my memory is playing tricks, SunOS a.out had this
> > feature.
> >
> > Do you mean support for shared libraries, or symbol preemption?
> >
> symbol preemption

My memory of this is it was dns lookups that wanted something like this.
SunOS really wanted the world to love YP but the world wanted Sun to
support DNS.  You could, and people did, make a shared lib that overloaded
the default gethostbyname(3) that wanted to do YP, the lib would provide
a DNS based one instead.

That's where I first learned of this stuff.  Gingell would know if you
want to know for sure.