X-Recipient: archive-cygwin AT delorie DOT com X-SWARE-Spam-Status: No, hits=-1.6 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,RCVD_IN_DNSWL_NONE,UNPARSEABLE_RELAY X-Spam-Check-By: sourceware.org X-Yahoo-SMTP: jenXL62swBAWhMTL3wnej93oaS0ClBQOAKs8jbEbx_o- Date: Tue, 4 Oct 2011 10:09:27 -0400 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: 1.7.9 Missing SIGPIPE? Message-ID: <20111004140927.GC20825@ednor.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com References: <4E833CB4 DOT 3060004 AT lysator DOT liu DOT se> <4E8B0FC6 DOT 9050600 AT lysator DOT liu DOT se> <4E8B116D DOT 3030905 AT gmail DOT com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E8B116D.3030905@gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com On Tue, Oct 04, 2011 at 04:00:13PM +0200, Marco Atzeri wrote: >On 10/4/2011 3:53 PM, Peter Rosin wrote: >> Peter Rosin skrev 2011-09-28 17:26: >>> Hi! >>> >>> When I use bash to build pipelines, they sometimes don't finish but >>> instead some process remains running. Example: >>> >>> $ tail -f -n 10000 log.txt | grep . | head -n 2 >>> >>> Almost instantly I get the expected two lines of output, but no prompt >>> back. I have to use ctrl-c. If I don't ctrl-c I can run pstree in >>> another terminal and see this: >>> >>> $ pstree >>> ??????????mintty?????????bash?????????tail >>> ??????mintty?????????bash?????????pstree >> >> This example is a poor one, as tail simply waits for a new line, when it >> gets a new line it forwards it to the pipe and promptly receives a >> SIGPIPE as grep is not there anymore. >> >> I'll get back when I have distilled a better STC. If I can... > >Hi Peter, >are you referring on something like SIGHUP on PTY closure ? > >http://cygwin.com/ml/cygwin/2011-07/msg00295.html >http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html Note that this thread contains your assertion that something isn't happening correctly but it isn't clear that your analysis is correct. But, no, SIGPIPE != SIGHUP and the above example clearly shows a completely different scenario than what is described in the above thread. cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple