dir = ENV.fetch("PROCIO_DIR", "/proc")
result = {} of String => Hash(Symbol, UInt64)
time = Time.local.to_s("%s%9N")

Dir.entries(dir).each do |entry|
  entry =~ /^\d+$/ || next 

  comm = File.read("#{dir}/#{entry}/comm").chomp
  result[comm] ||= {r: 0.to_u64, w: 0.to_u64}.to_h

  File.read_lines("#{dir}/#{entry}/io").each do |line|
    if line.starts_with?("read_bytes: ")
      result[comm][:r] += line.split(" ").last.to_u64
    elsif line.starts_with?("write_bytes: ")
      result[comm][:w] += line.split(" ").last.to_u64
    end
  end
end

result.each do |comm, v|
  if v[:r] + v[:w] > 0
    puts %(procio comm="#{comm}" read_bytes=#{v[:r]},write_bytes=#{v[:w]} #{time})
  end
end