CentOS - Sep 2006 - How to reattach to a failed ssh session or process

Hi, is there a way to "reconnect" to a ssh session that was
disconnected and left running processes in the linux server?

I know that's the purpose of the screen command, but just to spread
know-how, is that possible?

Example:
 3441 pts/0    S+     0:00 nano /etc/httpd/conf/httpd.conf

I remotely connect to a machine via ssh and started to edit apache
conf and i did not used screen (me bad). The session timed out due to
an internet glitch and I got disconnected.
How can I reattach (speaking in screen terms) to that ssh session or
gain control to the nano process (or any other)?

Thanks,


-- 
------------------------------------------------------------
Erick Perez
Panama Sistemas
Integradores de Telefonia IP y Soluciones Para Centros de Datos
Panama, Republica de Panama
Cel Panama. +(507) 6694-4780
------------------------------------------------------------

On Sep 20, 2006, at 10:41 AM, Erick Perez wrote:
> Hi, is there a way to "reconnect" to a ssh session that was
> disconnected and left running processes in the linux server?
>
> I know that's the purpose of the screen command, but just to spread
> know-how, is that possible?
>
> Example:
> 3441 pts/0    S+     0:00 nano /etc/httpd/conf/httpd.conf
>
> I remotely connect to a machine via ssh and started to edit apache
> conf and i did not used screen (me bad). The session timed out due to
> an internet glitch and I got disconnected.
> How can I reattach (speaking in screen terms) to that ssh session or
> gain control to the nano process (or any other)?
if you didn't start an instance of screen to begin with, you're out  
of luck; screen can't help you reattach to any arbitrary process,  
only to other instances of screen.

does nano have a robust autosave/autorecover facility?  if it does,  
just kill the nano process and start another (perhaps this time from  
within screen).  if not, curse your bad luck and consider using vi  
next time, which can deal with this sort of problem.

-steve

--
If this were played upon a stage now, I could condemn it as an  
improbable fiction. - Fabian, Twelfth Night, III,v

On Wed, 2006-09-20 at 09:41 -0500, Erick Perez wrote:
> Hi, is there a way to "reconnect" to a ssh session that was
> disconnected and left running processes in the linux server?
> 
> I know that's the purpose of the screen command, but just to spread
> know-how, is that possible?
> 
> Example:
>  3441 pts/0    S+     0:00 nano /etc/httpd/conf/httpd.conf
> 
> I remotely connect to a machine via ssh and started to edit apache
> conf and i did not used screen (me bad). The session timed out due to
> an internet glitch and I got disconnected.
> How can I reattach (speaking in screen terms) to that ssh session or
> gain control to the nano process (or any other)?
You can't reconnect to a broken ssh connection, and in fact it
should have killed all the processes you were running.  However,
some editors will save your work when terminated abnormally and
let you recover in a different session.  For example, if you used
vi filename
and were disconnected, you could recover later with
vi -r filename
I don't know anything about nano, though.

-- 
  Les Mikesell
   lesmikesell at gmail.com

On Wednesday 20 September 2006 11:12, Les Mikesell
wrote:
> On Wed, 2006-09-20 at 09:41 -0500, Erick Perez wrote:
> > Hi, is there a way to "reconnect" to a ssh session that was
> > disconnected and left running processes in the linux server?
> You can't reconnect to a broken ssh connection, and in fact it
> should have killed all the processes you were running.  
Unfortunately, I have seen many instances where ssh sessions do like this; if 
one happens to be running a yum update in one, and yum is downloading 
packages (putting yum into its unkillable mode, which, in my opinion is such 
an annoying thing; there have been a number of times I'd start up an update,
have it run for a while, then need to leave (taking my laptop with me, and 
thus disconnecting the session, which can cause its own problems) where I'd 
like to just simply CTRL-C yum and have it do the Right Thing; yum just 
cycles to the next mirror (at least the last time a couple of weeks ago it 
did this) when you hit CTRL-C OR when you send yum a SIGTERM)), then you can 
get some really wierd artifacts with unkillable but not running yum 
processes; I have seen a few where SIGKILL didn't do anything, and all 
because of a network glitch. 
-- 
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772
(828)862-5554
www.pari.edu

Hi Erick:

General but good info about screen use:
http://www.linuxjournal.com/article/6340

I hope it will be useful for you.
-- 
Jordi Espasa Clofent

PGP id 0xC5ABA76A #http://pgp.mit.edu/
FSF Associate Member id 4281 #http://www.fsf.org/

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL:
<http://lists.centos.org/pipermail/centos/attachments/20060921/fb7b1186/attachment-0002.sig>

On Thursday 21 September 2006 09:29, Craig White wrote:
> man screen
>
> screen creates a detachable session
Yes, I know.  I've used it and dtach both.  And it's usually the case
that
when I need to detach and reattach is typically when I've not run screen or 
dtach prior.  Typically when I do run them, I haven't needed them; like any 
thing, it needs to become a habit, and I've just not made it a habit as yet.

dtach is quite a bit simpler and smaller than screen; it doesn't, of course,
do as much either.
-- 
Lamar Owen
Director of Information Technology
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC  28772
(828)862-5554
www.pari.edu