From owner-freebsd-current Mon Jun 8 18:25:41 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA21378 for freebsd-current-outgoing; Mon, 8 Jun 1998 18:25:41 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from mail1.its.rpi.edu (root@mail1.its.rpi.edu [128.113.100.7]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA21362 for ; Mon, 8 Jun 1998 18:25:35 -0700 (PDT) (envelope-from drosih@rpi.edu) Received: from [128.113.24.47] (gilead.acs.rpi.edu [128.113.24.47]) by mail1.its.rpi.edu (8.8.8/8.8.6) with ESMTP id VAA92978 for ; Mon, 8 Jun 1998 21:25:30 -0400 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-Sender: drosih@pop1.rpi.edu Message-Id: In-Reply-To: <199806082025.NAA00919@dingo.cdrom.com> References: Your message of "Mon, 08 Jun 1998 16:05:35 EDT." Date: Mon, 8 Jun 1998 21:29:13 -0400 To: current@FreeBSD.ORG From: Garance A Drosihn Subject: Re: Variant Link implementation (Was: Re: lorder problem: ....... ) Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At 1:25 PM -0700 6/8/98, Mike Smith wrote: >> Garance Drosihn wrote: >> I have a question, given the subject of this thread. Are we talking >> about something that is only available when processing links, or are >> we talking about something that would be available for any pathname >> reference? > > We're only talking about substitutions on the target field of symbolic > links. > >> In AFS, I can reference /place/program/@sys/src, as long as /place >> is in an AFS file system. ("@sys" is the literal string used to >> indicate the afs-system-variable, and afs turns that into some >> string such as "sun4x_55", depending on what platform you are on >> when the variable is expanded). > > This would require parsing *every* path component. I don't think > that the overheads involved in this would be popular at all. For what it's worth, AFS only allows the variable name to be at the start of a path component (and in fact I think the component has to be nothing but a variable name). So, there isn't a lot of parsing overhead for paths which do not reference a variable. Basically it's just a "if ( *pathpart == '@' ) { process_variables() }". I'm not saying that freebsd should necessarily do the same thing, I just wanted to describe what AFS does minimize the overhead of parsing... --- Garance Alistair Drosehn = gad@eclipse.its.rpi.edu Senior Systems Programmer or drosih@rpi.edu Rensselaer Polytechnic Institute To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message