From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14659 invoked by alias); 11 Apr 2011 16:38:47 -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: 15955 Received: (qmail 23006 invoked from network); 11 Apr 2011 16:38:45 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) 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=3.3.1 Received-SPF: none (ns1.primenet.com.au: domain at csr.com does not designate permitted sender hosts) Date: Mon, 11 Apr 2011 17:38:35 +0100 From: Peter Stephenson To: Zsh Users Subject: Re: $pipestatus and shell functions Message-ID: <20110411173835.385fba1f@pwslap01u.europe.root.pri> In-Reply-To: References: Organization: Cambridge Silicon Radio X-Mailer: Claws Mail 3.7.8 (GTK+ 2.22.0; i386-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.103.11.49] X-Scanned-By: MailControl A_10_80_00 (www.mailcontrol.com) on 10.68.0.134 On Mon, 11 Apr 2011 17:52:24 +0200 J=C3=A9r=C3=A9mie Roquet wrote: > $ foo() { false | true } > $ true | foo ; echo $pipestatus > 1 0 > $ foo() { false | false } > $ true | foo ; echo $pipestatus > 1 1 > $ foo() { true | true | true } > $ false | foo ; echo $pipestatus > 0 0 0 >=20 > So $pipestatus is defeated by multiple pipelining=E2=80=A6 >=20 > Is this by design? I don't think this particular effect is deliberate. You're falling foul of (i) a shell function looks like a job to the shell (ii) it appears that function is being made the current job, so generates the pipe status when it exits (the same happens if you use a { ... } expression there, so that's not a workaround). However, there's some truly horrible handling for job control in complicated cases like this (what is supposed to get signals and what do you return to if you get one?) so it's quite possible that those two contributing factors are themselves deliberate. I'm not entirely convinced, though; it surprises me that that the notion of the current job changes like that. > If so, is there some not-so-complicated workaround > to get the exit code of process A in =E2=80=9C A | B =E2=80=9D for any B = (ie. even if > B is itself a shell function with a pipe)? Do you need B to be running in the current shell? If not, A | ( B ) will work. --=20 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, Cambr= idge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom