Path: csiph.com!goblin1!goblin.stu.neva.ru!usenet.stanford.edu!not-for-mail From: Greg Wooledge Newsgroups: gnu.bash.bug Subject: Re: Strange behaviour from jobs -p in a subshell Date: Tue, 13 Nov 2018 10:09:41 -0500 Lines: 19 Approved: bug-bash@gnu.org Message-ID: References: <563c6188-c905-db81-f330-b79bf17e4413@case.edu> NNTP-Posting-Host: lists.gnu.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: usenet.stanford.edu 1542122777 7815 208.118.235.17 (13 Nov 2018 15:26:17 GMT) X-Complaints-To: action@cs.stanford.edu To: bug-bash@gnu.org Envelope-to: bug-bash@gnu.org Mail-Followup-To: bug-bash@gnu.org Content-Disposition: inline In-Reply-To: <563c6188-c905-db81-f330-b79bf17e4413@case.edu> User-Agent: NeoMutt/20170113 (1.7.2) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 139.137.100.1 X-BeenThere: bug-bash@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Bug reports for the GNU Bourne Again SHell List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com gnu.bash.bug:14811 On Tue, Nov 13, 2018 at 09:59:51AM -0500, Chet Ramey wrote: > On 11/13/18 4:28 AM, Christopher Jefferson wrote: > > Consider the following script. While the 3 sleeps are running, both jobs > > -p and $(jobs -p) will print 3 PIDs. Once the 3 children are finished, > > jobs -p will continue to print the 3 PIDs of the done Children, but > > $(jobs -p) will only print 1 PID. $(jobs -p) always seems to print at > > most 1 PID of a done child. > > Since the $(jobs -p) is run in a subshell, its knowledge of its parent's > jobs is transient. In this case, the subshell deletes knowledge of the > jobs it inherits from its parent, but hangs onto the last asynchronous job > in case the subshell references $!. > > Chet If the goal is to obtain the result of "jobs -p" and use it in a script, I would suggest redirecting the output of jobs -p to a temp file, then reading it. That skips the subshell.