Re: Passing unicode filenames to start-process on Windows?

[Eli Zaretskii <eliz@gnu.org>]

> From: Klaus-Dieter Bauer <bauer.klaus.dieter@gmail.com>
> Date: Fri, 8 Jan 2016 00:31:38 +0100
> Cc: emacs-devel@gnu.org
> 
> - I want at some point to write an incremental backup utility 
> that uses md5sum to identify renamed files. Since precompiled
> Windows binaries are 32bit, only the first 512MB of any given
> file are accessible to elisp however, so I wanted to use 
> GnuWin32's md5sum.exe (but it turns out that it doesn't 
> support unicode filenames anyway). 

Emacs 25 can be built --with-wide-int, in which case the 512MB limit
goes up to almost 2GB.  I believe the precomiled binaries of the next
version will use this configure-time option.  So maybe this is still a
relevant alternative for you.

> - I want to verify a convention where filenames should mirror 
> the metadata in my music library. Here I intended to write 
> an elisp tool (for easy interactive processing im Emacs) 
> and tried to use ffmpeg (which does support unicode filenames
> in cmd.exe). 

You could have Emacs write a batch file that invokes ffmpeg with those
Unicode file names (encoded in UTF-16, of course, not UTF-8!), and
then run the batch file as the sub-process.  Will that work for you?

> I checked and both tools allow reading the input data from 
> a pipe (`type UNICODE.mp3 | ffmpeg -i - ...` or `md5sum` 
> respectively), so that workaround is applicable to all my usecases. 

Yes, that's another possibility.