gistfile1.rb

#!/usr/bin/env ruby

require 'socket'

localhost = Socket.gethostbyname(Socket.gethostname).first
npackets = ARGV[0] ? ARGV[0].to_i : 1_000

def top_n(name, data)
	data.map { |h,stats|
		[h, stats[name]]
	}.sort_by { |h,n|
		-n
	}.reject { |h,n| n.zero? }.map { |h,n|
		"\t%10.02fk : %s" % [n.to_f / 1024, h]
	}
end

($stderr << "Waiting for #{npackets} packets...").flush
raw_data = IO.popen("sudo tcpdump -tt -c #{npackets} 2>/dev/null").readlines
$stderr.puts "Done"

hosts = raw_data.map { |l|
	l.chomp!
	a = l.split(/ /)
	timestamp, wtf1, src, wtf2, dst, * = a
	size = a.last.to_i
	{ :src => src, :dst => dst.sub(/:$/, ''), :size => size }
}.inject(Hash.new { |x,y| x[y] = {:up => 0, :down => 0} }) { |h,a|
	next(h) if a[:size].zero?
	if a[:src].start_with?(localhost)
		h[a[:dst]][:up] += a[:size]
	elsif a[:dst].start_with?(localhost)
		h[a[:src]][:down] += a[:size]
	end
	h
}

ups = top_n(:up, hosts)
downs = top_n(:down, hosts)

puts "Uploading:", *ups
puts "Downloading:", *downs