new_contents: import shlex
  import sys
  import re
  from subprocess import Popen, PIPE
  
  def extractMacAddress(ampStatLine):
      macAddr = None
      items = ampStatLine.split( " " )
      for index in range(len(items)):
          if (items[index] == "MAC") and ((index+1) < len(items)):
              if re.match("[0-9a-f]{2}([-:])[0-9a-f]{2}(\\1[0-9a-f]{2}){4}$", items[index+1].lower()):
                  return items[index+1]
      return macAddr
  
  device = "eth0"
  if len(sys.argv) > 1:
      device = sys.argv[1]
  
  cmd = "ampstat -m -i {}".format(device)
  process = Popen(shlex.split(cmd), stdout=PIPE)
  (output, err) = process.communicate()
  exit_code = process.wait()
  
  allowedMacAddrMap = dict()
  
  outputArray = output.splitlines()
  for entries in outputArray:
      macAddr = extractMacAddress(entries)
      if macAddr is not None:
          # Check if mac address is allowed on the network
          print macAddr
  
  
  
  
subject: Read ampstat -m -i <device> and print out the mac addresses on the powerline network