Re: EShell tips on SSH?

[Wenshan Ren]

On Tuesday, January 15, 2013 6:32:34 PM UTC+11, Bob Proulx wrote:
> Wenshan Ren wrote:
> 
> > I manage a few VMs via SSH. As an Emacs user, I'm considering to get
> 
> > everything done without leaving Emacs.
> 
> 
> 
> Sure.
> 
> 
> 
> > So far I've met two problems:
> 
> > 
> 
> > 1. ssh -A
> 
> >    ssh -A does agent forwarding, but I can't find the EShell
> 
> >    equivalent by searching the Emacs Info.
> 
> 
> 
> How are you invoking ssh?
> 
> 
> 
> My first thought is the use of the emacs "tramp" module.  This is
> 
> quite well documented and very useful.  If you are using tramp please
> 
> say so.  If you are not using tramp then look up the documentation and
> 
> read up on tramp.  You will like it.
> 
> 
> 
> >    How do you achieve the same effect of ssh -A in Emacs?
> 
> 
> 
> I don't recommend to forward your agent.  If you do forward your agent
> 
> only forward it to systems that you trust.  Because root on the remote
> 
> system can make use of your forwarded agent.
> 
> 
> 
> If you do want to forward your agent anyway I would set it up to do so
> 
> in your ssh configuration file.  That would avoid the need for a
> 
> command line option.  Then when Emacs and Tramp use ssh it will get
> 
> the agent forwarding because of the ssh configuration.  Something like
> 
> this usually in your $HOME/.ssh/config file:
> 
> 
> 
>   Host foo.example.com
> 
>     ForwardAgent yes
> 
> 
> 
> If you do this then your ssh-agent will be forwarded through tramp
> 
> shell and tramp eshell sessions.  I tested this just now and it worked
> 
> okay for me.
> 
> 
> 

Yes, I invoke ssh using tramp so I can edit files on remote machines with my 
beloved and well configured editor.

Putting FowardAgent yes in ~/.ssh/config works :) 

> > 2. cd /
> 
> >    After `cd /ssh:username@host', `cd /' will change directory to /
> 
> >    of my local machine.  Is there any way to make EShell behave like
> 
> >    a ordinary bash sshed to a remote machine?
> 
> 
> 
> I think the idea for "cd" in eshell is that "/ssh:username@host" is
> 
> just a directory path like any other.  Therefore "cd /" will also be a
> 
> path like any other.  It isn't special.  It isn't a chroot.
> 
> 
> 
> Even if you use "shell" (instead of "eshell") you are still inside
> 
> emacs.  I note that with shell doing "cd /" will stay on the remote
> 
> machine and won't crawl out of the facade.  I am not arguing against
> 
> eshell.  But just sayhing that shell implements this feature as you
> 
> wish it.  If you use shell then you will be ssh'd into the machine and
> 
> cd / will take you to the root of the remote machine as you desire.
> 
> 

Got it, I will raise a change request as Michael suggested.

> 
> Bob


Thank you very much, Bob.


- Wenshan