lister

itemname = "Cobble"
dir = "+Y"

local directions = { [0]=0,[1]=1,[2]=2,[3]=3,[4]=4,[5]=5,["down"] = 0, ["up"] = 1, ["-Z"] = 2, ["+Z"] = 3, ["-X"] = 4, ["+X"] = 5, ["+Y"] = 1, ["-Y"] = 0}
directions.south = directions["+Z"]
directions.east = directions["+X"]
directions.north = directions["-Z"]
directions.west = directions["-X"]

function getID(id, meta)
	if meta == nil then
		meta = 27268
	else
		meta = bit.bxor(meta, 0x6E6C)
	end
	local uuid = bit.bxor(id, 0x4F89) * 0x8000 + bit.bxor(meta, 0x3A69)
	return uuid
end

function getStack(uuid, c)
	-- Reverse RG's fancy math
	local subt = bit.band(uuid, 0xffff)
	local dexorm = bit.bxor(subt, 0x3a69)
	local metadata = nil
	if dexorm ~= 28262 then -- item takes dmg
		metadata = bit.bxor(dexorm, 0x6e6c)
	end
	local id = bit.bxor((uuid-subt)/0x8000, 0x4f89)
	-- put it in to a nice table
	local stack = {}
	stack.amount = c
	stack.id = id
	stack.meta = metadata
	return stack
end

function getStacks(direction, invDirection)
	if not peripheral.isPresent(direction) then
		return false, "No Peripheral"
	end
	if peripheral.getType(direction) ~= "interactiveSorter" then
		return false, "Not a sorter"
	end
	local stacks = {}
	for uuid,count in pairs(peripheral.call(direction, "list", directions[invDirection])) do
		table.insert(stacks, getStack(uuid, count))
	end
	return true, stacks
end

rednet.open("right")

while true do
	s,inv = getStacks("back",dir)
	if #inv > 0 then
		item = { [1]=itemname, [2]=inv[1].amount }
		text = textutils.serialize(item)
		rednet.broadcast(text)
	else
		item = { [1]=itemname, [2]=0 }
		text = textutils.serialize(item)
		rednet.broadcast(text)
	end
	os.sleep(10)
end