Re: Adding streams for standard out and standard err

[Eli Zaretskii <eliz@gnu.org>]

> From: phillip.lord@russet.org.uk (Phillip Lord)
> Date: Wed, 20 Jul 2016 23:48:43 +0100
> 
> For a while I've wanted Emacs to have the ability to write to standard
> out, and/or standard err, when not running in batch. Mostly, I've wanted
> for debugging, as it involves touching no buffers at all.

Can we take a step back and talk about the need and the use cases?

Here're some thoughts related to this:

 . We already have (append-to-file START END FILENAME), which can be
   used to write a buffer or a string to a file.  FILENAME can be
   "/dev/stderr" on Posix platforms, for example, or it can be a real
   file name.

 . On TTY frames, writing to standard streams can end up on the
   screen, in which case it will mess up the display.

 . On GUI frames, writing to standard streams can end up in some
   unpredictable place on the system, or even in the bitbucket,
   depending on what window system, desktop, and window manager are
   installed.  On some systems, standard streams have invalid file
   descriptors in GUI sessions.

So this proposed functionality sounds (a) not really necessary, and
(b) somewhat unreliable/dangerous.  If you have specific use cases
where the existing functionality doesn't fit the bill, and the issues
mentioned above are non-issues, please describe those use cases.

Thanks.