Any way to delete all NON LM objects?

[MantasJ]

Code:

data = io.readfile('/home/ftp/data.esf')

if data then
  lines = data:split('\n')

  for _, line in ipairs(lines) do
    props = line:split('\t')

    if #props >= 5 then
      addr = props[1]:match('[0-9]+/[0-9]+/[0-9]+$')

      if addr then
        name = props[2]:trim()
        id = buslib.encodega(addr)
        db:update('objects', { name = name }, { id = id })
      end
    end
  end

  os.remove('/home/ftp/data.esf')
end

Is there any way to use this code with .json files instead of .esf? The reason is that .esf does not export knx objects which are not linked to anything and in addition it does not support some symbols from my language so instead of normal symbol it puts "?" in that place.