addCommandHandler( "getxyz",
    function ()
        local x,y,z = source:getPosition()
        outputChatBox( tostring(x)..","..tostring(y)..","..tostring(z) )
    end
)

---------------
[12:17:09] ERROR: mtadm\core_s.lua:30: attempt to index global 'source' (a nil v
alue)