mac_addr_osx

#!/usr/bin/env  ruby
require 'optparse'


def current_mac_address_from_ifconfig()
  ret = `ifconfig en0`
  match = ret.match(/([a-f0-9]{2}:*){6}/)
  mac_addr = match[0]
end

def default_mac_addr
  if !File.exists?("/usr/local/etc/mac_addr") then 
    mac_addr = current_mac_address_from_ifconfig
    open("/usr/local/etc/mac_addr", "w"){|f| f.puts mac_addr } 
  end
  mac_addr = open("/usr/local/etc/mac_addr").read.strip
end

def random_mac_addr
  mac_addr = `openssl rand -hex 6 `
  mac_addr = mac_addr.scan(/.{1,2}/).join(":")
end

def change_mac_addr_cmd_str(mac_addr)
  cmd = [
  # "sudo /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport -z",
  "sudo ifconfig en0 ether #{mac_addr} ",
  # "networksetup -detectnewhardware",
  "networksetup -setairportpower en0 off",
  "networksetup -setairportpower en0 on",
  ].map(&:strip).reject{|e| e==""}

  cmd.join(";")
end



def main ()

  params = ARGV.getopts('ed')
  mac_addr =  nil
  if  params["d"]==false &&  params["e"]==false then 
    puts current_mac_address_from_ifconfig
    exit
  end


  begin 
    if params["e"] then 
      mac_addr = random_mac_addr
    end
    if params["d"] 
      mac_addr = default_mac_addr
    end
    cmd = change_mac_addr_cmd_str(mac_addr)
    `#{cmd}`

    raise unless mac_addr == current_mac_address_from_ifconfig

    puts "change mac_addr to  #{mac_addr}"
  rescue  => e 
    puts "#{mac_addr} is not valid. retry...."
    retry 
  end
end



main()