[lltx] mkluatexfontdb -> fontdbutil

[Élie Roux]

Hi Karl, all,

> 1) Why do you need to rename it?  What's wrong with adding the features
> to it under its existing name?  Just because it will do other things?

We are fine with any name. The difference is that the default
behavior has changed: an update has to be requested explicitly
using the -u switch. We are reluctant to break existing behavior,
so we were looking for a way to both change things and keep them
the way they are without code duplication.

> 2) If you use argv[0] to change the behavior, please also make cmdline
> options to control it in the same way.  It's trivial to do that, and
> that way, users can use an alias or their own trivial wrapper script to
> get the behavior they want with the name they want, which turns out to
> be surprisingly useful in all kinds of unforeseen situations.

Agreed. A tracker item has been opened:

   https://github.com/lualatex/luaotfload/issues/4


> 3) I definitely think "lua", at least, should be in the name.
> "fontdbutil" doesn't give any clues -- there are endless numbers of
> fonts, databases, and utilities in the world, after all.

Ok. What about luafontdbutil?

> What are the features you want to add?

New features have already been added in the future version:
  - rudimentary querying for feedback on whether and how the database 
resolves a font name (--find option).
  - have it output basic information for a font name (--info switch).

It will help users to see what's in their database and how to query it 
with the good name.

What do you think?

Thank you,
-- 
Elie