Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!nosc!ucsd!rutgers!cmcl2!adm!smoke!gwyn From: gwyn@smoke.ARPA (Doug Gwyn ) Newsgroups: comp.unix.wizards Subject: Re: SVID changes Message-ID: <8334@smoke.ARPA> Date: 12 Aug 88 02:26:41 GMT References: <4964@killer.DALLAS.TX.US> <3395@vpk4.UUCP> <249@quintus.UUCP> <3716@whutt.UUCP> <274@quintus.UUCP> Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB)) Organization: Ballistic Research Lab (BRL), APG, MD. Lines: 36 For the benefit of those whose knowledge about the SVID is limited to what they read in this newsgroup, let me clarify a few points. So far as I am aware, there have been two "issues" of the SVID. An "issue" basically obsoletes the previous issue. However, an Issue in general consists of an open-ended set of individual Volumes published at different times. So far I have three Volumes in Issue 2 of the SVID. Volumes 1 & 2 basically supplanted, then extended, what was in SVID Issue 1. Volume 3 contains interface specs for features introduced after UNIX System V Release 2, plus a few revisions to specs in the earlier volumes. In general, revisions extend the functionality without changing it, or correct technical errors in earlier specs. There have been few significant changes to the interfaces specified in earlier issues/ volumes of the SVID, which is as one would expect -- large changes would cause trouble for existing applications, and riling existing customers is no way to keep their business. For the most part, each new volume has merely introduced additional functionality. The SVID was designed to provide for controlled evolution of the specs, which is necessary to correct problems and track future developments. (The alternative, a "stagnant standard", is of comparatively little value.) The rule was, an impending change would be pre-announced at least three years in advance, and would be flagged in the SVID as such. For example, from the beginning the UNIX "plot" and PWB/Graphics functionality was flagged as obsolescent. (In this particular case, no replacement has appeared!) I'm not sure the 3-year rule has been strictly followed in recent volumes.. Of course, the SVID development has gotten somewhat screwed up by the recent independent development of UNIX "standards" which AT&T will pretty much have to accommodate somehow. For example, there will have to be a considerable revision of the SVID for POSIX compatibility. I don't know if AT&T is planning on starting a new "issue" for that or adding another volume to Issue 2.