[texhax] \write17?

[Ulrike Fischer]

Am Sat, 20 Oct 2018 22:22:11 +0100 schrieb David Carlisle:

> In luatex there are 256 rather than 16 output streams, so it's different again.

To expand this: if files are perhaps processed with luatex too,
\write16 should not be used for messages. They can end in real files
and create quite a mess. See e.g.

https://tex.stackexchange.com/a/435226/2388

Some large number like \immediate\write333{hallo} or the \@unused
stream is safer here. 

-- 
Ulrike Fischer 
https://www.troubleshooting-tex.de/