[ESS] using R + ess-remote with screen in Emacs

[Vinh Nguyen]

Dear list,

I brought up [this](https://stat.ethz.ch/pipermail/ess-help/2009-June/005388.html)
issue before but a good solution never arised: being able to use
screen on a remote server (so if something goes wrong on my side I can
always resume that R session) inside of emacs in order to utilize ESS.
 The closest [thing](http://blog.nguyenvq.com/2009/06/01/run-screen-in-emacs-with-ansi-term-combine-this-with-emacs-ess-remote-r/)
I found to a good work flow was to use ansi-term or multi-term and
copying and pasting code in Emacs (ESS only worked nicely with
shell-mode; reason at the end).  Some would advise to use screen and
open emacs inside of that screen, and voila, you have the luxuries of
screen (attaching the session anywhere) and emacs+ESS (keybindings,
etc).  However, I prefer to use one main emacs session on my
laptop/netbook (all my configurations are there), where I can have
multiple projects and multiple R jobs opened at once.

I would like to share what I have working  (for the time being), with
the help of [Michael Zeller](http://home.michaelzeller.com/) in case
others are interested.

1.  Place the following in .emacs:
;; used to send screen keybindings to shell in emacs
(define-key shell-mode-map (kbd "C-l") (lambda (seq) (interactive "k")
(process-send-string nil seq)))
(define-key inferior-ess-mode-map (kbd "C-l") (lambda (seq)
(interactive "k") (process-send-string nil seq)))

2.  In xterm (or the likes), ssh to the remote server and start
screen.  Detach it.  (Need to do this first as starting the initial
screen in emacs shell-mode becomes very ugly with the printing;
resuming the same screen session also becomes messy in xterm)

3.  In emacs, M-x shell.  Set:
$ TERM=xterm ## give clearing capabilities to shell-mode

4.  ssh to remote server.  screen -r to resume the screen session.
start R.  M-x ess-remote.

5.  Send R code from R source files like before!

6.  To detach or do anything screen related, precede EACH keybinding
with C-l.  For example, C-a C-d to detach will now be C-l C-a C-l C-d.
 Yes this is cumbersome, but I don't imagine screen keybinding to be
used much at this stage since we are developing and debugging R code
for say a simulation study =].

I would also like to note (for archival reasons) that ess-remote does
not work with ansi-term and multi-term because of the
inferior-ess-mode command, which stems from comint-mode and
inferior-ess-send-input.  If you remove this command in ess-remote,
you don't get an error but u can only send one line of code at a time
from the R file.

Hope this helps someone out there.

Vinh Nguyen
PS This post is also posted on my blog at
http://blog.nguyenvq.com/2010/07/11/using-r-ess-remote-with-screen-in-emacs/