From owner-freebsd-hackers@FreeBSD.ORG Sat Feb 22 23:06:53 2014 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 61BB5396 for ; Sat, 22 Feb 2014 23:06:53 +0000 (UTC) Received: from smtp.digiware.nl (smtp.digiware.nl [31.223.170.169]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 1BE50165E for ; Sat, 22 Feb 2014 23:06:49 +0000 (UTC) Received: from rack1.digiware.nl (unknown [127.0.0.1]) by smtp.digiware.nl (Postfix) with ESMTP id AFE591534D1; Sun, 23 Feb 2014 00:06:40 +0100 (CET) X-Virus-Scanned: amavisd-new at digiware.nl Received: from smtp.digiware.nl ([127.0.0.1]) by rack1.digiware.nl (rack1.digiware.nl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iq8LYojNCWPD; Sun, 23 Feb 2014 00:06:38 +0100 (CET) Received: from [192.168.10.9] (vaio [192.168.10.9]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by smtp.digiware.nl (Postfix) with ESMTPSA id 895BD153448; Sun, 23 Feb 2014 00:06:38 +0100 (CET) Message-ID: <53092D83.6050603@digiware.nl> Date: Sun, 23 Feb 2014 00:06:43 +0100 From: Willem Jan Withagen User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Perry Hutchison , jordan.hubbard@gmail.com Subject: Re: Thoughts on Multi-Symlink Concept References: <530049a1.XXZ1PjZFgRyCu9X6%perryh@pluto.rain.com> In-Reply-To: <530049a1.XXZ1PjZFgRyCu9X6%perryh@pluto.rain.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-filesystems@freebsd.org, freebsd-hackers@freebsd.org X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Feb 2014 23:06:53 -0000 On 16-2-2014 6:16, Perry Hutchison wrote: > Jordan Hubbard wrote: > >> Even variant symlinks (/bin -> /${ARCH}/bin), which can expand >> differently depending on the user context, have clearly >> understandable semantics - you know that the symlink is going >> to expand to exactly one file no matter what ARCH is set to. > > s/file/pathname/ > > Depending on what ARCH is set to, the expanision may or may not > point to any actual file (or directory, or ...) Yes, please can we get these .... Apollo Domain systems had those, and they were great. Set SYSTYPE to BSD4 and get the BSD tree and all that came with it, or SYSV to get the other stuff. Would indeed work great for things like /bin or even /usr/local/etc -> /${HOST}/usr/local/etc I was running a special patch version 2.2 at one time, that had variant replacement in the lookup-cache routines. But I never was able to figure out a handy way to get the info back into the kernel. So I gave up. One would need to get at the user environment of the process, and then parse and scrutinize the ENV every time you need to use a replacement. So probably libc is the place to put it, but then you get into trouble again when somebody uses the not standard libc... Also got a lot of flack from people suggesting it would create security problems.... (I beg to differ) But I would really like the timewarp back to 1985. --WjW