Call external executable or shell command from Lua?

[zangman]

It seems that calls to io and os are disabled by default. If I want to interface with an external program from factorio (both send and receive data), whats the best way to do it through a mod? Can I have my application running as a local webserver and send requests to it?

[DaveMcW]

RCON for input. It requires a headless server to work.
game.write_file() for output.

[zangman]

Thanks. Rcon seems pretty complex, since I'm just sending data out, write_file works for now.