Re: Lua environment variables and supporting parallel versions

[Shmuel Zeigerman <shmuz@...>]

John Belmonte wrote:
> For Lua packagers: I realized that to support multiple installed
> versions of Lua, versioned aliases of the Lua environment variables
> (LUA_INIT, LUA_PATH, and LUA_CPATH) are needed.  I propose names as
> follows (e.g. for Lua 5.1):
>
>   LUA_5_1_INIT
>   LUA_5_1_PATH
>   LUA_5_1_CPATH
>
> If a versioned alias is set, it takes precedence over the non-versioned
> variable.
>
> --John

To use multiple versions of Lua one may use
a script analyzing _VERSION variable, e.g.:

-- environment variable
LUA_INIT=@c:/lua/init.lua

-- file c:/lua/init.lua
local v = string.sub(_VERSION, 5, 7)
if v == "5.0" then
    dofile("c:/lua/5.0/compat-5.1.lua")
else
    dofile("c:/lua/5.1/init.lua")
end

--
Shmuel