disallow interaction with "outside world"

[Nathan Hüsken <nathan.huesken@...>]

Dear Lua community,

I am completely new to lua (not to programming) and also to this
community, so hello everyone :-).

I am considering to use Lua as a scripting language for scripts to which
I have special requirements.
The requirements are because the scripts deal with sensitive data. At
the same time they can be written by third party people. So the danger
of someone writing a "virus" in this scripts and sneaking the data out
(outside of the lua environment) in some way that would give them access
to it must not be possible.

On the other hand, the scripts are loose on other requirements. They do
not need to interact with the outside of the scripting environment very
much. The data they need can be provided through a handful of variables
(or maybe some other mechanism in lua I do not know yet :-) ). All
interactions and outputs happen by 2-3 functions.

So my Idea: simple do not load a handful of libraries when starting the
lua interpreter (I am guessing "io" and "os") and by this I guarantee
that no data can go out except by the functions provided by me.

Now, is this possible? Can I be sure that this way that it is impossible
to "sneak" data out?

Thanks - even if you can not help - for reading through this long post :-).

Best,
Nathan