Re: run emacs in batch mode without a tty

[Eli Zaretskii <eliz@gnu.org>]

> From: Steinar Bang <sb@dod.no>
> Date: Sat, 04 Jul 2015 08:56:00 +0200
> 
> >>>>> Eli Zaretskii <eliz@gnu.org>:
> 
> > It does?  It doesn't for me:
> 
> >   emacs -batch --eval "(princ \"Hello, world\!\n\")" < /dev/null > foo
> 
> > I get no crash and the expected message in the file 'foo'.
> 
> >From the example above, how do you know that emacs doesn't require a tty
> as seen from the startup shell, just to start up and run in batch?

The original message talked about crashes.  It's easy to know I don't
get that ;-)

As for what you ask, I don't understand the question.  What do you
mean by "a tty as seen from the startup shell", and why is that
relevant?  Once Emacs is invoked, why should it care about the shell
that invoked it?

> (It's a real question, not a rethorical one. I'm curious. I guess the
> tty requirement might differ, depending on the OS? Different for
> GNU/linux (and other unixoid systems) and Win32?)

They might, but (a) I tried my example both on GNU/Linux and on
MS-Windows, and (b) I explicitly asked for evidence that a tty device
needs to exist for Emacs to start in batch mode, because if such a
precondition exists, it must be a bug of some kind.  Meanwhile, the OP
says that "emacs -batch" works on their system, which apparently lacks
a tty device, and that is yet another evidence that a tty device is
not needed in batch mode, as I'd expect.