localmt=getmetatable(_G)or{}functionmt.__index(t,k)ifk~='arg'thenerror('Tried to view nil global '..tostring(k),2)endreturnnilendfunctionmt.__newindex(t,k,v)ifk~='arg'thenerror('Tried to write global '..tostring(k),2)endrawset(t,k,v)endsetmetatable(_G,mt)