Prints the MAC addresses of captured packets

mac_printer.rb

require 'pcaprub'

snaplength = 65535
promiscous_mode = true 
timeout = 0

capture = PCAPRUB::Pcap.open_live('en0', snaplength, promiscous_mode, timeout)

capture.each_packet do |packet|
  mac = packet.data.unpack("C*").
        map { |i| i.to_s(16) }.
        map { |i| if i.length == 1 then "0#{i}" else i end}.
        slice(6, 6).
        join(":")
  puts mac
end