function kill_stdio()
  io.stdout:close()
  io.stderr:close()
  io.stdin:close()
end

function qspawn(program) -- quit  spawn
  kill_stdio()
  os.execute(program .. " &> /dev/null &")
end

function rows(con, stmt)
  local cur = assert (con:execute(stmt))
  return function ()
    return cur:fetch()
  end
end