OS Module
os.exec(command: string, ...): { ok: string?, err: string? }
Executes the command as a child process, waiting for it to finish and collecting all of its output.
os.time(): float
Returns the number of non-leap-microseconds since January 1, 1970 UTC.
os.sleep(secs: number)
Puts the current thread to sleep for at least the specified amount of time.