listen

rednet.open("right")
items = {}
amount = {}
term.clear()

function update()
	term.clear()
	for i=1,#items do
		term.setCursorPos(1,i)
		term.write(items[i].." - "..tostring(amount[items[i]]))
	end
end

function checkfor(str)
	exist = false
	for i=1,#items do
		if items[i] == str then
			exist = true
		end
	end
	if not exist then
		table.insert(items,str)
	end
end

while true do
	event,id,message = os.pullEvent()
	if event == "rednet_message" then
		item = textutils.unserialize(message)
		checkfor(item[1])
		amount[item[1]] = item[2]
		update()
	end
end