From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruce Korb Subject: Re: '>;' redirection operator [was: [1003.1(2008)/Issue 7 0000530]: Support in-place editing in sed (-iEXTENSION)] Date: Thu, 22 Dec 2011 14:09:30 -0800 Message-ID: <4EF3AA9A.9070009@gnu.org> References: <201112221539.pBMFdlaj011933@penguin.research.att.com> <4EF39B1E.80709@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from fencepost.gnu.org ([140.186.70.10]:33954 "EHLO fencepost.gnu.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924Ab1LVWJh (ORCPT ); Thu, 22 Dec 2011 17:09:37 -0500 In-Reply-To: <4EF39B1E.80709@redhat.com> Sender: dash-owner@vger.kernel.org List-Id: dash@vger.kernel.org To: Eric Blake Cc: David Korn , austin-group-l@opengroup.org, Bash - Bug , zsh-workers@zsh.org, dash , miros-discuss@mirbsd.org On 12/22/11 13:03, Eric Blake wrote: > I assume on the ksh implementation that the temp file is discarded if > the command (simple or compound) feeding the redirection failed? One would hope! > If the > redirection is used on a simple command, is there any shorthand for > specifying that the destination name on success also be fed as an > argument to the command, to avoid the redundancy of having to type > 'file' both before and after the'>;' operator? Doesn't the shell already have enough hieroglyphs? It is what intimidates many folks from figuring it out. > I assume that this is > like any other redirection operator, where an optional fd number can be > prepended, as in '2>; file' to collect stderr and overwrite file on > success? When the exact opposite is the useful variation? I.e. keep-on-failure. "-i" for sed is simple, understandable and implemented a lot. Please don't add another glyph to the standardized shell. Let us not slide on slippery slopes. Shells can always add some useful builtins: sh_move_if_changed sh_save_on_success sh_save_on_failure to cope with this stuff. Or you can write your own such library for your own use. ">;" is not an answer for sed-as-a-batch-editor anyway, which is what "-i" really is.