From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: Why does grep add /dev/null the first time? Date: Thu, 14 Aug 2014 22:13:09 +0300 Message-ID: <83tx5ehol6.fsf@gnu.org> References: <9c9b05f0-e060-4c00-a393-aaae65f524be@googlegroups.com> NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1408043619 29003 80.91.229.3 (14 Aug 2014 19:13:39 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 14 Aug 2014 19:13:39 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Aug 14 21:13:32 2014 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XI0Sq-0007Es-Av for geh-help-gnu-emacs@m.gmane.org; Thu, 14 Aug 2014 21:13:32 +0200 Original-Received: from localhost ([::1]:55732 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XI0Sp-0002Sk-Qt for geh-help-gnu-emacs@m.gmane.org; Thu, 14 Aug 2014 15:13:31 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35293) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XI0SY-0002PA-1Z for help-gnu-emacs@gnu.org; Thu, 14 Aug 2014 15:13:19 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XI0SS-00025E-4R for help-gnu-emacs@gnu.org; Thu, 14 Aug 2014 15:13:13 -0400 Original-Received: from mtaout29.012.net.il ([80.179.55.185]:43267) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XI0SR-000256-T7 for help-gnu-emacs@gnu.org; Thu, 14 Aug 2014 15:13:08 -0400 Original-Received: from conversion-daemon.mtaout29.012.net.il by mtaout29.012.net.il (HyperSendmail v2007.08) id <0NAB004009410J00@mtaout29.012.net.il> for help-gnu-emacs@gnu.org; Thu, 14 Aug 2014 22:13:04 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout29.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0NAB004229DSZ800@mtaout29.012.net.il> for help-gnu-emacs@gnu.org; Thu, 14 Aug 2014 22:13:04 +0300 (IDT) In-reply-to: <9c9b05f0-e060-4c00-a393-aaae65f524be@googlegroups.com> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 80.179.55.185 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:99216 Archived-At: > Date: Thu, 14 Aug 2014 11:12:07 -0700 (PDT) > From: guido@dropbox.com > > The (minor) issue with this is that the first time after starting Emacs (and only the first time) the shell command actually executed has "/dev/null" appended (causing the search to return no results). Any subsequent invocations it will work fine. > > What am I missing? See the doc string of grep-use-null-device, which explains that. Its default value is 'auto-detect', which causes Emacs to invoke Grep once for the purposes of detecting how to invoke it thereafter.