X-Recipient:	archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status:	No, hits=-0.9 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,T_RP_MATCHES_RCVD
X-Spam-Check-By:	sourceware.org
To:	cygwin AT cygwin DOT com
From:	Andrew DeFaria <Andrew DOT DeFaria AT tellabs DOT com>
Subject:	Re: Unable to disown process
Date:	Wed, 06 Jul 2011 13:15:11 -0700
Lines:	48
Message-ID:	<iv2fog$69i$1@dough.gmane.org>
References:	<iv25no$u76$1 AT dough DOT gmane DOT org> <CAHWeT-YB1RV+zXtM1+EnNvKVyymsj9BqYHrGe2nEPM25oL+Ypw AT mail DOT gmail DOT com>
Mime-Version:	1.0
User-Agent:	Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.18) Gecko/20110616 Lightning/1.0b2 Thunderbird/3.1.11
In-Reply-To:	<CAHWeT-YB1RV+zXtM1+EnNvKVyymsj9BqYHrGe2nEPM25oL+Ypw@mail.gmail.com>
X-IsSubscribed:	yes
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Unsubscribe:	<mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
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 7/6/2011 12:12 PM, Andy Koppe wrote:
> On 6 July 2011 18:24, Andrew DeFaria wrote:
>> I have the following script that I use to tunnel nntp traffic:
>>
>>    #!/bin/bash
>>    nohup ssh -NL 1119:news.mozilla.org:119 \
>>          -L 2119:news.gmane.org:119 \
>>          -L 3119:nntp.perl.org:119 \
>>       andrew AT defaria DOT com>  /dev/null 2>&1&
>>
>>    disown
>>
>> If I run this script it works fine and I'm tunneled. The problem is I cannot
>> exit the terminal in which I invoked this script. When I attempt to do this
>> the terminal hangs. I can close the terminal (mintty BTW) forcefully and the
>> ssh session remains but it was my understanding that disown should allow you
>> to exit the current shell with the backgrounded/disowned process continuing
>> to run. In fact I tested this on RHEL and it worked as expected. What's up
>> with Cygwin?
> Mintty stays open as long as any processes are connected to it, i.e.
> until it gets an EOF from its underlying pseudo terminal device,
> whereas other terminals quit as soon as their direct child process
> finishes. The Cygwin console behaves the same as mintty in this regard
> though.
Ah ha!
> Nohup doesn't disassociate a process from its terminal, it just blocks
> the SIGHUP signal for indicating when the terminal is gone. And
> 'disown' removes a job from the shell's job table, but again, the
> job's processes will remain connected to the terminal.
>
> You can use the 'setsid' utility from the util-linux package to invoke
> a program in its own session, i.e. without connection to the terminal
> it is invoked from. For example:
>
> setsid ssh -NL 1119:news.mozilla.org:119 \
>           -L 2119:news.gmane.org:119 \
>           -L 3119:nntp.perl.org:119 \
>           andrew AT defaria DOT com
Excellent description and solution. Thanks.
> No need for 'nohup', redirections, backgrounding, or 'disown' with this.
Of course those were all the desperate things I was trying to get this 
to work...

Actually I still need backgrounding as without it my ~/bin/tunnel just 
hangs on the setsid command...
-- 
Andrew DeFaria <http://defaria.com>
What is the speed of dark?


--
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

- Raw text -