From owner-freebsd-questions@FreeBSD.ORG Fri Jan 24 17:23:45 2014 Return-Path: Delivered-To: freebsd-questions@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 E9C636E5; Fri, 24 Jan 2014 17:23:44 +0000 (UTC) Received: from mx1.fisglobal.com (mx1.fisglobal.com [199.200.24.190]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id AE43C14D2; Fri, 24 Jan 2014 17:23:44 +0000 (UTC) Received: from smarthost.fisglobal.com ([10.132.206.191]) by ltcfislmsgpa02.fnfis.com (8.14.5/8.14.5) with ESMTP id s0OHNhiB005803 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Fri, 24 Jan 2014 11:23:43 -0600 Received: from THEMADHATTER (10.242.181.54) by smarthost.fisglobal.com (10.132.206.191) with Microsoft SMTP Server id 14.3.174.1; Fri, 24 Jan 2014 11:23:41 -0600 From: Sender: Devin Teske To: "'Warren Block'" , "'Devin Teske'" References: <20140123185604.4cbd7611@gumby.homeunix.com> <04a201cf1878$8ebce540$ac36afc0$@FreeBSD.org> <04aa01cf187e$cfcf9ef0$6f6edcd0$@FreeBSD.org> <04d201cf1895$20956890$61c039b0$@FreeBSD.org> In-Reply-To: Subject: RE: awk programming question Date: Fri, 24 Jan 2014 09:23:36 -0800 Message-ID: <050a01cf1929$051c0670$0f541350$@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 15.0 Thread-Index: AQImboywfYAMtXakWRoTJ2P0ROJwWwJr8ryGAjfseSYDBtd9AwHDspKgAVvTlWgA1aCjmwLA5WZtAnzeO/eZXodP0A== Content-Language: en-us X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.87, 1.0.14, 0.0.0000 definitions=2014-01-24_04:2014-01-24,2014-01-24,1970-01-01 signatures=0 Cc: 'RW' , freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 24 Jan 2014 17:23:45 -0000 > -----Original Message----- > From: Warren Block [mailto:wblock@wonkity.com] > Sent: Thursday, January 23, 2014 6:23 PM > To: 'Devin Teske' > Cc: 'RW'; freebsd-questions@freebsd.org > Subject: RE: awk programming question > > On Thu, 23 Jan 2014, dteske@FreeBSD.org wrote: > > >> No, the non-greedy modifier to a standard quantifier: > >> > >> echo "abczabczabcz" | perl -ne '/(a.*z)/; print "$1\n"' > >> abczabczabcz > >> > >> echo "abczabczabcz" | perl -ne '/(a.*?z)/; print "$1\n"' > >> abcz > > > > Craziness! Wonder when that crept in. > > I've been using it for at least a decade, so it's probably been around at least > twice that long. ...So probably came out about twenty years after the sed > and awk feature sets were frozen. :) > > > I'm not entirely sure how I feel about that -- in terms of > > readability, I'm not sure if the following is more readable: > > > > /(a[^z]*z)/ > > Wait till you see the other PCRE stuff. There are lots of things that really > make it much more powerful. perlre(1) covers it all, sketchily and not really > in order. > > I've said elsewhere, and will repeat again: "Mastering Regular Expressions" > by Jeffrey E. F. Friedl (the owl book) is amazing. My first edition (1997) does > not have some of the newer Perl stuff, but it's now up to a third edition: > > http://shop.oreilly.com/product/9780596528126.do Does it cover "back references" ? Definitely one of the more powerful but esoteric regular expressions (e.g., you want to match a string that starts with a quote and has a matching terminating quote, but not match a string that has a quote without matching termination). If-so, I'm totally buying that book. -- Devin _____________ The information contained in this message is proprietary and/or confidential. If you are not the intended recipient, please: (i) delete the message and all copies; (ii) do not disclose, distribute or use the message in any manner; and (iii) notify the sender immediately. In addition, please be aware that any message addressed to our domain is subject to archiving and review by persons other than the intended recipient. Thank you.