Checking whether a shared library has been loaded

[Dirk Laurie <dirk.laurie@...>]

I wish to test whether a shared library has already been loaded.

This is the best I can come up with.

is_loaded_library = function (LIB_NAME)
-- returns fully qualified name of loaded library or `false`
   for key,val in pairs(debug.getregistry()) do
      if type(key)=='userdata' and type(val)=='table' then
         for k in pairs(val) do
            if type(k)=='string' and k:match(LIB_NAME..'$') then
               return k
            end
         end
      end
   end
   return false
end

Is there a better way?