How to run a function from a lua file on interactive terminal?

I’m reading some source codes of  a project, which is a combination of c++ and lua, they are interwined through luabind.

There is a la.lua file, in which there is a function exec(arg). The lua file also uses functions/variables from other lua file, so it has statements as below in the beginning

module(…, package.seeall);

print(“Loading “…debug.getinfo(1).source…”…”)

require “client_config”

now I want to run la.exec() from interactive terminal(on linux), but I get errors like

attempt to index global ‘lg’ (a nil value)

if I want to import la.lua, I get

require “la”

Loading @./la.lua…

./la.lua:68: attempt to index global ‘ld’ (a nil value)

stack traceback:

./lg.lua:68: in main chunk

C: in function ‘require’

stdin:1: in main chunk

what can I do?