function Utf8to32(utf8str)
	assert(type(utf8str) == "string")
	local res, seq, val = {}, 0, nil
	for i = 1, #utf8str do
		local c = string.byte(utf8str, i)
		if seq == 0 then
			table.insert(res, val)
			seq = c < 0x80 and 1 or c < 0xE0 and 2 or c < 0xF0 and 3 or
			      c < 0xF8 and 4 or --c < 0xFC and 5 or c < 0xFE and 6 or
				  error("invalid UTF-8 character sequence")
			val = (c & 2^(8-seq) - 1)
		else
			val = ((val<< 6)| (c & 0x3F))
		end
		seq = seq - 1
	end
	table.insert(res, val)
	table.insert(res, 0)
	return res
end

for k,v in pairs(Utf8to32("sss"))
do
    if v~=0 then
        print(string.format("%04x", v))
    end
end