Path: csiph.com!xmission!news.snarked.org!news.linkpendium.com!news.linkpendium.com!panix!usenet.stanford.edu!not-for-mail From: Chet Ramey Newsgroups: gnu.bash.bug Subject: Re: Incorrect example for `[[` command. Date: Sun, 22 Sep 2019 13:53:37 -0400 Organization: ITS, Case Western Reserve University Lines: 26 Approved: bug-bash@gnu.org Message-ID: References: <8e7c8ea4-2fdf-4809-0b50-ea1bfbbec165@case.edu> Reply-To: chet.ramey@case.edu NNTP-Posting-Host: lists.gnu.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: usenet.stanford.edu 1569174828 14230 209.51.188.17 (22 Sep 2019 17:53:48 GMT) X-Complaints-To: action@cs.stanford.edu Cc: chet.ramey@case.edu, bug-bash@gnu.org To: Ilkka Virta , hk Envelope-to: bug-bash@gnu.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=case.edu; s=smtp-primary; t=1569174821; bh=8gT/khSyM4h56CSA+SmQy258QQHDibJvjSzTol+N8sE=; h=Reply-To:Cc:Subject:To:References:From:Message-ID:Date: MIME-Version:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=DmJsVRKP03u+I8gKFuDzUzyKpzt5tgbkoGk0MNux//JPfWQf/+dN0KGqEMiOMb4Mc2 ZHOOhUbQcf1fjhLfegJn9y3/DZjMYGKHNsZNpZQr9ySalr8fS54khTR/kuxloKKH4P0 ChI314Eqc197xP7ubHcwpnuQpdUHTgDbzCaXuCpqgt69q5zVFxki2Tk7Vitsf7xK/Zl 7OB11V6p/ZXliZnCBktHOxxJ01D+z6P/dAx5igl42RO1A2taO5fAeqpNlpa7thjWfzG 3571DFAozQnggc1BvXI7WYcwJzjlYXUcBwcFrlU/FEu0q2+OwoSiBeyQXw+kE7ixtcs 2h3leFJQ== DKIM-Signature: v=1; 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Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 In-Reply-To: Content-Language: en-US X-Junkmail-Status: score=8/90, host=mpv1-2015.case.edu X-Junkmail-PrAS-Raw: score=8/90, refid=2.7.2:2019.9.22.164518:17:8.317, ip=, rules=__YOUTUBE_RCVD, DKIM_SIGNATURE, __X_GOOGLE_DKIM_SIGNATURE, __HAS_REPLYTO, __HAS_CC_HDR, __MULTIPLE_RCPTS_CC_X2, __SUBJ_REPLY, __BOUNCE_CHALLENGE_SUBJ, __BOUNCE_NDR_SUBJ_EXEMPT, __TO_MALFORMED_2, __TO_NAME, __TO_NAME_DIFF_FROM_ACC, __HAS_REFERENCES, __REFERENCES, __HAS_FROM, FROM_EDU_TLD, __HAS_MSGID, __SANE_MSGID, DATE_TZ_NA, __USER_AGENT, __MOZILLA_USER_AGENT, __MIME_VERSION, __IN_REP_TO, __CT, __CT_TEXT_PLAIN, __CTE, __REPLYTO_SAMEAS_FROM_ADDY, __REPLYTO_SAMEAS_FROM_ACC, __FROM_DOMAIN_IN_ANY_CC2, __REPLYTO_SAMEAS_FROM_DOMAIN, __DKIM_ALIGNS_1, __DKIM_ALIGNS_2, __ANY_URI, __URI_WITH_PATH, __URI_NO_WWW, __CP_URI_IN_BODY, __SUBJ_ALPHA_NEGATE, __URI_IN_BODY, __URI_NOT_IMG, __FORWARDED_MSG, __BODY_NO_MAILTO, __NO_HTML_TAG_RAW, BODYTEXTP_SIZE_3000_LESS, BODY_SIZE_900_999, __MIME_TEXT_P1, __MIME_TEXT_ONLY, __URI_NS, HTML_00_01, HTML_00_10, DKIM_ALIGNS, [TRUNCATED], so=2010-03-03 19:42:08, dmn=2016-08-03-0138 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 129.22.103.226 X-BeenThere: bug-bash@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Bug reports for the GNU Bourne Again SHell List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Mailman-Original-Message-ID: X-Mailman-Original-References: <8e7c8ea4-2fdf-4809-0b50-ea1bfbbec165@case.edu> Xref: csiph.com gnu.bash.bug:15400 On 9/21/19 5:34 AM, Ilkka Virta wrote: > On 21.9. 03:12, hk wrote: >> Thanks for the reply. I was wrong in my report. It does match values like >> aab and  aaaaaab  in its original form. > > In some systems, yes. (It does that on my Debian, but doesn't work at all > on my Mac.) > >> It is syntatically correct as a regular expression. > > [[:space:]]*?(a)b  isn't a well-defined POSIX ERE: > >   9.4.6 EREs Matching Multiple Characters > >   The behavior of multiple adjacent duplication symbols ( '+', '*', '?', >   and intervals) produces undefined results. It's ambiguous, but it can be interpreted as valid. I wonder why they used "undefined" instead of the usual "unspecified." -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRU chet@case.edu http://tiswww.cwru.edu/~chet/