# File lib/facter/util/macaddress.rb, line 11
11:     def self.macaddress
12:       iface = default_interface
13:       Facter.warn "Could not find a default route. Using first non-loopback interface" if iface.empty?
14: 
15:       macaddress = `#{ifconfig_command} #{iface} | /usr/bin/awk '/ether/{print $2;exit}'`.chomp
16:       macaddress.empty? ? nil : macaddress
17:     end