This page describes the lua apis avaliable in CraftOS.

coroutine, io, math, string, table and most of the globals behave the same as standard lua.
Type "help os" to learn the operating system API.
Type "help shellapi" to learn the shell API.
Type "help fs" to learn the filesystem API.
Type "help redstone" to learn the redstone API.
Type "help term" to learn the terminal API.