From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15659 invoked by alias); 12 Sep 2016 16:20:12 -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: 21876 Received: (qmail 11768 invoked from network); 12 Sep 2016 16:20:12 -0000 X-Qmail-Scanner-Diagnostics: from mailout1.w1.samsung.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(210.118.77.11):SA:0(-2.2/5.0):. Processed in 0.422975 secs); 12 Sep 2016 16:20:12 -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=-2.2 required=5.0 tests=RP_MATCHES_RCVD autolearn=unavailable autolearn_force=no version=3.4.1 X-Envelope-From: p.stephenson@samsung.com X-Qmail-Scanner-Mime-Attachments: | X-Qmail-Scanner-Zip-Files: | Received-SPF: none (ns1.primenet.com.au: domain at samsung.com does not designate permitted sender hosts) X-AuditID: cbfec7ef-f79e76d000005b57-5b-57d6d5b4b016 Date: Mon, 12 Sep 2016 17:19:59 +0100 From: Peter Stephenson To: Zsh Users Subject: Re: Do file descriptors survive to subshell? Message-id: <20160912171959.2516a91e@pwslap01u.europe.root.pri> In-reply-to: Organization: Samsung Cambridge Solution Centre 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-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrLIsWRmVeSWpSXmKPExsWy7djP87pbrl4LN7h1Ushix8mVjA6MHqsO fmAKYIzisklJzcksSy3St0vgytiwZjd7wSq2irv/fjE3MP5l6WLk5JAQMJG4+/8YI4QtJnHh 3nq2LkYuDiGBZYwSVy9/Y4JwupkkWlr+MsJ07Nn8gBmu6sDk1ywQzhQmieUnpkL1n2GU2Prw IVTmLKPEllunmED6WQRUJa593c8KYrMJGEpM3TQbbK6IgKLEmV/fwGqEBUwl9t3+zgxi8wrY S0z69A6onoODUyBYYtlmPZAwv4C+xNW/n5ggTrKXmHnlDCNEuaDEj8n3wJ5jFtCR2LbtMTuE LS+xec1bsLMlBP6zSbQs/swOMlNCQFZi0wFmiDkuEltmnIKaKSzx6vgWdghbRuLy5G5ogPUz Sjzp9oWYM4NR4vSZHWwQCWuJvtsXGSGW8UlM2jadGWI+r0RHmxBEiYfEr/XXoOY4Sqz5/oJl AqPiLCRnz0Jy9iwkZy9gZF7FKJJaWpybnlpsqFecmFtcmpeul5yfu4kRmAhO/zv+fgfj0+aQ Q4wCHIxKPLwNq6+FC7EmlhVX5h5ilOBgVhLhPXIFKMSbklhZlVqUH19UmpNafIhRmoNFSZx3 74Ir4UIC6YklqdmpqQWpRTBZJg5OqQbGtqWufo/urdy84NMsX6s4p5v7vrVlc+XmndNbs1O7 Q9Cgevv3qQcfpgrc9EhMrpnE7HnLyvpVtW3aVJPrH47yVy+91b3w/8p7l+c2cO7rufAyZOLT uoLJO15b/dg8Q35+hmDuEaVJVqnb/p9KU+DofhnwQuZkcfX9Nd5dWVyHkybctW9tSOd4q8RS nJFoqMVcVJwIAM9rIQoAAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrOIsWRmVeSWpSXmKPExsVy+t/xa7pNV6+FG6w8zGGx4+RKRgdGj1UH PzAFMEa52WSkJqakFimk5iXnp2TmpdsqhYa46VooKeQl5qbaKkXo+oYEKSmUJeaUAnlGBmjA wTnAPVhJ3y7BLWPDmt3sBavYKu7++8XcwPiXpYuRk0NCwERiz+YHzBC2mMSFe+vZuhi5OIQE ljBK9O5rYodwpjFJPL3/mQnCOcco8XDxLSjnLKPE16MTGUH6WQRUJa593c8KYrMJGEpM3TQb LC4ioChx5tc3JhBbWMBUYt/t72D7eAXsJSZ9egdWzykQLPGmbx0LxNBljBI79ywFa+YX0Je4 +vcTE8SB9hIzr5xhhGgWlPgx+R7YE8wCWhKbtzWxQtjyEpvXvAVbICSgLnHj7m72CYzCs5C0 zELSMgtJywJG5lWMIqmlxbnpucVGesWJucWleel6yfm5mxiBkbTt2M8tOxi73gUfYhTgYFTi 4W1YfS1ciDWxrLgy9xCjBAezkggvAzAOhXhTEiurUovy44tKc1KLDzGaAkNmIrOUaHI+MMrz SuINTQzNLQ2NjC0szI2MlMR5p364Ei4kkJ5YkpqdmlqQWgTTx8TBKdXAWC1non+g/iXXmhRO GfaHZcsa1ry4eNq41F4j88HMpTG1d8ofCbPk7ZuqKiQh9IHjQsedlytuPjIwzPE8uuxoikXE xKjINpk9ri87Tx3eG6gfWSrFGWasX3uf91J5s/Lp2RI3t2zn7z9ut+TDgjAVsdMb+26rbo9/ MOGB6a2ViXeKnOwPTfJRVGIpzkg01GIuKk4EABBneV+6AgAA X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20160912162003eucas1p21515e1ce4a42b94b5b7916121b9dffed X-Msg-Generator: CA X-Sender-IP: 182.198.249.180 X-Local-Sender: =?UTF-8?B?UGV0ZXIgU3RlcGhlbnNvbhtTQ1NDLURhdGEgUGxhbmUb?= =?UTF-8?B?7IK87ISx7KCE7J6QG1ByaW5jaXBhbCBFbmdpbmVlciwgU29mdHdhcmU=?= X-Global-Sender: =?UTF-8?B?UGV0ZXIgU3RlcGhlbnNvbhtTQ1NDLURhdGEgUGxhbmUbU2Ft?= =?UTF-8?B?c3VuZyBFbGVjdHJvbmljcxtQcmluY2lwYWwgRW5naW5lZXIsIFNvZnR3YXJl?= X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDA1Q0QwNTAwNTg=?= CMS-TYPE: 201P X-HopCount: 7 X-CMS-RootMailID: 20160912160148eucas1p1c7f423821260c611c9b34fbe47bfcf86 X-RootMTR: 20160912160148eucas1p1c7f423821260c611c9b34fbe47bfcf86 References: It depends how the FD was opened. > But the "survive FD" feature should work only for > "exec zsh-5.2-dev-1", not "zsh-5.2-dev-1", shouldn't it ... well, if you ran zsh-5.2-dev-1 3< myfile you'd be a bit annoyed if FD 3 was closed, wouldn't you? And of course 0, 1 and 2 are left open. So for FDs opened by / known to the user, it's expected that they'll survive; internal FDs used by the shell should be closed. One example of an FD the shell uses internally is for terminal management --- we don't do this directly on the user-visible FDs for reasons I don't think I ever fully understood. Because this is opened early, it's usualy FD 10, i.e. just outside the easily accessible range (that traditionally shells keep away from allowing you to manipulate directly) 0 to 9. pws