From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13861 invoked by alias); 18 Apr 2018 06:29:28 -0000 Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Workers List List-Post: List-Help: List-Unsubscribe: X-Seq: 42678 Received: (qmail 27148 invoked by uid 1010); 18 Apr 2018 06:29:27 -0000 X-Qmail-Scanner-Diagnostics: from mail-wr0-f181.google.com by f.primenet.com.au (envelope-from , uid 7791) with qmail-scanner-2.11 (clamdscan: 0.99.2/21882. spamassassin: 3.4.1. Clear:RC:0(209.85.128.181):SA:0(-1.9/5.0):. Processed in 1.267772 secs); 18 Apr 2018 06:29:27 -0000 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.1 X-Envelope-From: stephane.chazelas@gmail.com X-Qmail-Scanner-Mime-Attachments: | X-Qmail-Scanner-Zip-Files: | DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to:user-agent; bh=zs77e5iVMbfhMztMZO0LDRGm+kfKfx0gR9NAaU56mIE=; b=MAE9+EcaFXi+ZpNgEYtOZM2B31TL64wXcLPxytB2nYdnHZpz+uVQJbjldXg+na42jd +jk5UqdQ6AeEX0/Ols3rHGFHFVaTD7z/8C9e0y7me5JBdrJKXXDNI4qpClhXPhSA2sp0 HiybyEwYa5nvytPWNaS55fBCxlpu8YfVtjoFDhrxSIjvgVZtrq6tQ79ubWqTVwJxiG6A AEkQrgvofavINjIzvqLakpEeLBZdvaqSpkQeFlM/Wa2+ZWwLHLh7xYQWHWck20ver9KZ Bl1AV8eD9B4G0MSFRVEdomvn3tuKtvJb046j93iLbXGmhWv43QSdg4upZOwh5VIebVVy hPbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to:user-agent; bh=zs77e5iVMbfhMztMZO0LDRGm+kfKfx0gR9NAaU56mIE=; b=Mso5i0TjNTh0wOGZWj8Ce6nxcL10yVoollvwqjhyF2fKnKHbcNFaq+F5zGQE8jZzcI JQJ4u2ksOwm9mMRupZKTb1noHA3ngv+BBVjCow2dGntlb66KDYt+Ygl6a5tsx1Fa4c7U uwnaSCmj1ZR68DZnGTHmE/cWzDSbvUWKk9moxw9ulU0nMXNAwUHTfnmNFizeV4GGQlF0 BD0QUIsmwzKnPk563OAyMRUNaM0y6fMLEMjFDd0RCA2/RV3DEMBr4xqP44QKOgfcXyP/ Qy+7kc7G8QtXaRD8s5YmM2neG1BWPZy3gL3r/VOe+SQnYCCH06r9SKp/cBS73YvGcTmc RX0Q== X-Gm-Message-State: ALQs6tDwPnpWbLLToPS/bkXUA70HkqeJ97rNL7V7lg6GCNio0AeWROkx 9syuMeO8tf4QcgiEg1yUTk4= X-Google-Smtp-Source: AIpwx4/oMMUd4SSHq2/3DOR+GDBy3LVkioHJYrAkUAvqF+PSPP5ulgNnJ1jt+iaZ6/VBAbupXlr4jQ== X-Received: by 2002:adf:aac5:: with SMTP id i5-v6mr533898wrc.16.1524032962922; Tue, 17 Apr 2018 23:29:22 -0700 (PDT) Date: Wed, 18 Apr 2018 07:29:20 +0100 From: Stephane Chazelas To: Peter Stephenson Cc: zsh-workers@zsh.org Subject: Re: "echo | ps -j $(:) | cat | cat | cat" runs components in different process groups Message-ID: <20180418062920.GA5840@chaz.gmail.com> Mail-Followup-To: Peter Stephenson , zsh-workers@zsh.org References: <180324150945.ZM32251@torch.brasslantern.com> <20180410124545.13fccd5d@camnpupstephen.cam.scsc.local> <20180410145926.64c4f671@camnpupstephen.cam.scsc.local> <180411151025.ZM19332@torch.brasslantern.com> <20180412172342.52df6b10@camnpupstephen.cam.scsc.local> <20180415162326.GA12549@chaz.gmail.com> <20180415185804.GB12549@chaz.gmail.com> <180416223910.ZM32002@torch.brasslantern.com> <20180417101947.5fd347df@camnpupstephen.cam.scsc.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180417101947.5fd347df@camnpupstephen.cam.scsc.local> User-Agent: Mutt/1.5.24 (2015-08-30) 2018-04-17 10:19:47 +0100, Peter Stephenson: [...] > > % echo ${foo::=bar} & echo $foo > > [1] 31940 > > bar > > % bar [...] > It certainly looks rather unexpected. I think most of us staring at it > would assume the entire command line was evaluated in the background. > It's hard to believe anyone is deliberately relying on this behaviour. > I think it would be fine to change with a note about the > incompatibility. [...] But then again (as already mentioned in 42527) $ echo ${foo::=bar} | echo $foo bar is equally surprising to me (and at the root of most of the problems in this thread as the expansions are not done in the job's process group). foo | bar to me is like foo & bar except for the pipe() that connects them. I suspect if you reuse "time" code, that won't address this case. -- Stephane