From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 129228 invoked by alias); 30 Aug 2017 23:26:53 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 129219 invoked by uid 89); 30 Aug 2017 23:26:52 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.1 required=5.0 tests=AWL,BAYES_40,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.2 spammy=H*r:NNFMP, HX-Yahoo-Newman-Property:ymail-3, H*F:D*rogers.com, H*M:rogers X-HELO: nm22-vm8.access.bullet.mail.gq1.yahoo.com Received: from nm22-vm8.access.bullet.mail.gq1.yahoo.com (HELO nm22-vm8.access.bullet.mail.gq1.yahoo.com) (216.39.63.230) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 30 Aug 2017 23:26:42 +0000 Received: from [216.39.60.173] by nm22.access.bullet.mail.gq1.yahoo.com with NNFMP; 30 Aug 2017 23:26:40 -0000 Received: from [67.195.22.118] by tm9.access.bullet.mail.gq1.yahoo.com with NNFMP; 30 Aug 2017 23:26:40 -0000 Received: from [127.0.0.1] by smtp113.sbc.mail.gq1.yahoo.com with NNFMP; 30 Aug 2017 23:26:40 -0000 X-Yahoo-SMTP: _oUbE.SswBCQ_d_LvSIk7sZfv6R7Is8n9OVRVjJJh3dhqEgGPCs- From: "Michel LaBarre" To: Subject: Bash monitor mode remains enabled if disabled in .bashrc Date: Wed, 30 Aug 2017 23:26:00 -0000 Message-ID: <000701d321e7$6ed52220$4c7f6660$@rogers.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2017-08/txt/msg00275.txt.bz2 Playing with set -m/+m and shopt -s lastpipe, in an interactive bash shell, I came across a situation which is minor unless it has broader implications for others that I do not know about. Specifically if "set +m" is present in .bashrc, it looks like job control (monitor mode) is off in an interactive shell (as per "echo $-") but it is actually on. I ran into this with "shopt -s lastpipe" behaviour with and without job control. I can also reproduce it with "sleep 25&" then "fg" will fail with "no job control". If I "set +m" within the interactive shell rather than, or in addition to, .bashrc, both the flags ($-) and behaviour (lastpipe and fg) reflect job control being off. I include only an example with lastpipe. FYI - from bash reference for shopt: lastpipe If set, and job control is not active, the shell runs the last command of a pipeline not executed in the background in the current shell environment. My .bashrc includes "shopt -s lastpipe" and "set +m". My objective was to produce the same conditions as within a script for debugging a messy statement at a command line and I had no need for job control while doing this and I would sometimes forget to disable monitor mode after a new bash. If somebody trying to debug some bash statements and is unaware that a second "set +m" is required, they might be confused for a bit. (An option to make an interactive shell behave the same as a non-interactive shell might facilitate such debugging.) C:\mybin>bash $ echo "$-" # no "m" meaning monitor mode is off i.e. no job control... hiBHs $ echo abc | read zot # zot is therefore in a sub-process hence value not available in this process $ echo $zot $ set +m $ echo "$-" # still no m but behaviour is different... hiBHs $ echo abc | read zot # read zot now running in this process so value is available $ echo $zot abc $ bash --version GNU bash, version 4.4.12(3)-release (x86_64-unknown-cygwin) By the way, the "s" set option ($- above) is not defined in the bash reference manual that I have and is not accepted by the "set" built into bash so I don't know how it gets set. (i.e."set -s s" or "set +s s" both fail with "invalid option".) Michel LaBarre -- 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