From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18774 invoked by alias); 12 Sep 2017 11:42:26 -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: X-Seq: 41683 Received: (qmail 22771 invoked by uid 1010); 12 Sep 2017 11:42:26 -0000 X-Qmail-Scanner-Diagnostics: from ioooi.vinc17.net 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(92.243.22.117):SA:0(-1.9/5.0):. Processed in 0.972967 secs); 12 Sep 2017 11:42:26 -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,RP_MATCHES_RCVD autolearn=ham autolearn_force=no version=3.4.1 X-Envelope-From: vincent@vinc17.net X-Qmail-Scanner-Mime-Attachments: | X-Qmail-Scanner-Zip-Files: | Date: Tue, 12 Sep 2017 13:42:20 +0200 From: Vincent Lefevre To: zsh-workers@zsh.org Subject: Re: [BUG] exec + builtin and traps Message-ID: <20170912114220.GB1794@zira.vinc17.org> Mail-Followup-To: zsh-workers@zsh.org References: <20170912100257.GA32535@zira.vinc17.org> <20170912111906.397cffec@pwslap01u.europe.root.pri> <20170912103919.GA1794@zira.vinc17.org> <20170912115006.4d1b964d@pwslap01u.europe.root.pri> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170912115006.4d1b964d@pwslap01u.europe.root.pri> X-Mailer-Info: https://www.vinc17.net/mutt/ User-Agent: Mutt/1.9.0-7151-vl-r99863 (2017-09-05) On 2017-09-12 11:50:06 +0100, Peter Stephenson wrote: > On Tue, 12 Sep 2017 12:39:19 +0200 > Vincent Lefevre wrote: > > No, by default (with TRAPS_ASYNC unset), traps are run *after* the > > child process has exited: > > True, but the *builtin* is an eval list, that only terminates when it > has executed an arbitrary set of other commands. The trap is executed > at the end of this list, before control returns back to eval. We are > not exec'ing sleep here, we are exec'ing eval, so there is time after > the *child* process is executed, as in the TRAPS_ASYNC doc you quote. > > eval, unlike exec, is not an permanent handoff of control to the > following command. OK, this was a bit confusing from the description of "eval" by POSIX, which describes it as a way to construct a command: The eval utility shall construct a command by concatenating arguments together, separating each with a character. The constructed command shall be read and executed by the shell. BTW, the way zsh handles "eval" is still strange: ---------------------------------------- trap 'echo foo' USR1 ( sleep 1; kill -USR1 $$; ) & eval "wait && echo bar" echo OK ---------------------------------------- outputs foo bar OK ---------------------------------------- trap 'echo foo' USR1 ( sleep 1; kill -USR1 $$; ) & wait && echo bar echo OK ---------------------------------------- outputs foo OK All the other shells output foo OK in both cases. -- Vincent Lefèvre - Web: 100% accessible validated (X)HTML - Blog: Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)