From owner-freebsd-hackers@FreeBSD.ORG Tue Mar 27 07:59:46 2007 Return-Path: X-Original-To: hackers@freebsd.org Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 48CF016A403 for ; Tue, 27 Mar 2007 07:59:46 +0000 (UTC) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (comp.chem.msu.su [158.250.32.97]) by mx1.freebsd.org (Postfix) with ESMTP id C34CE13C448 for ; Tue, 27 Mar 2007 07:59:43 +0000 (UTC) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (localhost [127.0.0.1]) by comp.chem.msu.su (8.13.4/8.13.4) with ESMTP id l2R7xbfK011681; Tue, 27 Mar 2007 11:59:37 +0400 (MSD) (envelope-from yar@comp.chem.msu.su) Received: (from yar@localhost) by comp.chem.msu.su (8.13.4/8.13.4/Submit) id l2R7xZpV011678; Tue, 27 Mar 2007 11:59:35 +0400 (MSD) (envelope-from yar) Date: Tue, 27 Mar 2007 11:59:34 +0400 From: Yar Tikhiy To: Joseph Koshy Message-ID: <20070327075934.GA10930@comp.chem.msu.su> References: <20070326135106.GG60831@comp.chem.msu.su> <84dead720703260827q29ed7f26hd79dde461fe50d9b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <84dead720703260827q29ed7f26hd79dde461fe50d9b@mail.gmail.com> User-Agent: Mutt/1.5.9i Cc: hackers@freebsd.org Subject: Re: sed -i X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Mar 2007 07:59:46 -0000 On Mon, Mar 26, 2007 at 08:57:14PM +0530, Joseph Koshy wrote: > >Recently noticed that our sed(1) differs from its GNU > >analog in that in -i mode it considers all files as a > >single sequence of lines while the latter treats each file > >independently. The in-line mode isn't in POSIX, so it isn't > >really clear which way is correct. > > Aren't sed's addresses required to be cumulative across its > input files? > > http://www.opengroup.org/onlinepubs/009695399/utilities/sed.html That makes sense for filter mode because it's equvalent to concatenating the files in advance: cat files ... | sed expression OTOH, in-place mode selected by a -i option can be seen as follows: for f in files ...; do sed expression < $f > $f.tmp && mv $f $f.bak && mv $f.tmp $f done I.e., each file preserves its individuality. This can be at logical conflict with cumulative addresses across all files. -- Yar