Re: run emacs in batch mode without a tty

[Sam Halliday <sam.halliday@gmail.com>]

On Friday, 3 July 2015 21:14:36 UTC+1, Eli Zaretskii  wrote:
> > Date: Fri, 3 Jul 2015 10:07:06 -0700 (PDT)
> > From: Sam Halliday <sam.halliday@gmail.com>
> > 
> > >   emacs -batch --eval "(princ \"Hello, world\!\n\")" < /dev/null > foo
> > 
> > Aah, the difference is that you're using `-batch`
> 
> Excuse me?  It was you who asked specifically about the batch mode:
> 
> > Is it possible to run emacs in batch mode without access to a tty? Is there a way to mock a tty for these purposes?
>   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I wasn't aware that there was a flag to turn emacs into a batch processor. You can invoke commands and load lisp files for purely automated testing without the -batch flag, and that is exactly what we are doing. I was calling that batch mode, but now I don't know what to call it.


> > and that does allow me to do *some* things in the docker container, but emacs seems to just exit when I start a `process`. The docs don't mention this as a caveat http://www.emacswiki.org/emacs/BatchMode
> 
> What do you mean by "start a process"?

I mean start a http://www.gnu.org/software/emacs/manual/html_node/elisp/Processes.html

> > Is there anything that you can think of that might cause a -batch emacs to exit early?
> 
> How do you see it exiting early?  Please provide the details of what
> you see, as I have no way of trying this on a system similar to yours.

Well, this is literally all the information I have: the stdout

http://fommil.com/github.com/ensime/ensime-emacs/drone/ee99fc5d368cafc2dd583520f9fe8e9e23faadb6

from running this script

https://github.com/fommil/ensime-emacs/blob/drone/test/run_emacs_tests.sh

The last thing we see is the output from this function call (which starts the process) https://github.com/fommil/ensime-emacs/blob/drone/ensime-startup.el#L215

So I'm interested to know what implication the -batch flag has for the functionality of emacs. Specifically: launching/monitoring processes, and navigating buffers (i.e. spoofing user actions).

Best regards,
Sam