From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21764 invoked by alias); 6 Mar 2012 11:44:20 -0000 Mailing-List: contact zsh-users-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Users List List-Post: List-Help: X-Seq: 16844 Received: (qmail 28286 invoked from network); 6 Mar 2012 11:44:17 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW, SPF_HELO_PASS autolearn=ham version=3.3.2 Received-SPF: none (ns1.primenet.com.au: domain at csr.com does not designate permitted sender hosts) Date: Tue, 6 Mar 2012 11:44:04 +0000 From: Peter Stephenson To: Subject: Re: [[ and [ Message-ID: <20120306114404.359e1c9d@pwslap01u.europe.root.pri> In-Reply-To: <20120306113532.789859ca@pwslap01u.europe.root.pri> References: <4F52D510.6000002@sergio.spb.ru> <120303202448.ZM21278@torch.brasslantern.com> <4F555B0B.1050401@sergio.spb.ru> <120305220555.ZM27709@torch.brasslantern.com> <4F55EF85.3050809@sergio.spb.ru> <20120306113532.789859ca@pwslap01u.europe.root.pri> Organization: Cambridge Silicon Radio X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.0; i386-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.101.10.170] X-Scanned-By: MailControl 7.6.6 (www.mailcontrol.com) on 10.68.0.133 On Tue, 6 Mar 2012 11:35:32 +0000 Peter Stephenson wrote: > However, > > [[ $foo -eq "" ]] > > does exactly what it looks like it does Sigh. Sort of. [ ... -eq ...] and [[ ... -eq ... ]] are numeric tests, so if foo is a string of zeros it's not doing what it looks like. I should have said [ $foo = "" ]] and [[ $foo = "" ]] or [[ $foo == "" ]] I don't know why it's that way round, it seems a bit illogical (which is why Perl is the other way), but it always has been that way. -- Peter Stephenson Software Engineer Tel: +44 (0)1223 692070 Cambridge Silicon Radio Limited Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK Member of the CSR plc group of companies. CSR plc registered in England and Wales, registered number 4187346, registered office Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom More information can be found at www.csr.com. Follow CSR on Twitter at http://twitter.com/CSR_PLC and read our blog at www.csr.com/blog