require recreation for ComputerCraft

--v2.0
_G["shell"] = shell
_G["multishell"] = multishell
_G.package = {
    ["loaded"] = {
        ["os"] = os;
        ["bit"] = bit;
        ["colors"] = colors;
        ["commands"] = commands;
        ["coroutine"] = coroutine;
        ["disk"] = disk;
        ["fs"] = fs;
        ["gps"] = gps;
        ["help"] = help;
        ["http"] = http;
        ["io"] = io;
        ["keys"] = keys;
        ["math"] = math;
        ["multishell"] = multishell;
        ["paintutils"] = paintutils;
        ["parallel"] = parallel;
        ["peripheral"] = peripheral;
        ["rednet"] = rednet;
        ["redstone"] = redstone;
        ["shell"] = shell;
        ["string"] = string;
        ["table"] = table;
        ["term"] = term;
        ["textutils"] = textutils;
        ["turtle"] = turtle;
        ["vector"] = vector;
        ["window"] = window;
    },
    ["path"] = "/System/libs/?;/System/libs/?.lib;/System/libs/?.lua;/libs/?;/libs/?.lib;/libs/?.lua",
    ["loaders"] = {
        [1] = function(name)
            if package.preload[name] then
                return true, package.preload[name]
            else
                return false, 'in "package.preload,"'
            end
        end;
        [2] = function(name)
            local path = string.gsub(package.path, "?", name)
            local result
            local file
            for subPath in string.gmatch(path, "([^;]+)") do
                file = io.open(subPath)
                if file then
                    result = subPath
                    break
                end
            end
            if not result then
                return false, 'in "package.path" with name "'..name..'"'
            end
            local text = file:read("*a")
            local module, err = load(text, name)
            if not module then
                return false, "Error in the module file: "..err
            end
            local env, meta = { }
            env._ENV = env
            meta = {
                __index = _G;
                name = tostring(env):gsub("table", "module");
                __tostring = function()
                    return meta.name
                end;
            }
            setmetatable(env, meta)
            setfenv(module, env)
            return true, module
        end
    },
    ["preload"] = { },
}
function _G.require( ... )
    local modules = { }
    for key, value in ipairs{ ... } do
        local message = ""
        if type(value) ~= "string" then error("Bad argument #"..key..": string expected, got "..type(value), 2) end
        if package.loaded[value] then
            modules[key] = package.loaded[value]
        else
            message = message..'Can\'t find module #'..key..' in "package.loaded",\n'
            for i=1, #package.loaders do
                local boolean, foo = package.loaders[i](value)
                if boolean then
                    local ok, module = pcall(foo)
                    if not ok then message = message..'Error in module "'..value..'": '..module.."\n"
                    else
                        if module == nil then
                            if next(getfenv(foo)) then
                                module = getfenv(foo)
                            else
                                module = true
                            end
                        end
                        if type(module) == "table" and getmetatable(module) == nil then
                            local meta
                            meta = {
                                __index = _G;
                                name = tostring(module):gsub("table", "module");
                                __tostring = function()
                                    return meta.name
                                end;
                            }
                            setmetatable(module, meta)
                        end
                        modules[key] = module
                        package.loaded[value] = module
                        break
                    end
                else
                    message = message..foo.."\n"
                end
            end
            if not modules[key] then
                error(message, 2)
            end
        end
    end
    return unpack(modules)
end
function _G.module(name, lib)
    if type(name) ~= "string" then error("Bad argument: string expected, got "..type(name), 2) end
    if lib == nil then lib = { } end
    if package.loaded[name] then error("Module with name \""..name.."\" has already loaded", 2)
    else package.loaded[name] = lib end
    return lib
end
function _G.unload(name)
    package.loaded[name] = nil
end
function os.multiEvent( ... )
    if not ... then
        return coroutine.yield()
    end
    while true do
        local var, var2 = { coroutine.yield() }
        for _, value in ipairs{ ... } do
            if var[1] == value then
                return unpack( var )
            end
        end
    end
end