lua5.1 setfenv test.

fenv.lua

-- lua51 setfenv tests

function setenv1()
    -- 1 is the calling function
    setfenv(1, {foo='1', print=_G.print})
    print(foo) -- prints 1
end

setenv1()

local print = _G.print
local setfenv = _G.setfenv
local _G = _G
local tostring=_G.tostring

function setenv2()
    -- 2 is the direct outer function
    setfenv(2, {bar='2'})
end

setenv2()
print(bar) -- prints 2


-- 0 means *thread* environment, and top level function will
-- pick up by default. but somehow baz isn't available
setfenv(0, {tostring=tostring, print=print, baz=0})
function setenv0()
    print(baz) -- prints nil?
end

setenv0()