Set a random MAC address on OSX

set_random_mac_address.sh

#!/bin/bash
# ether 3c:07:54:12:6d:fc

if [ -z "$1" ]; then
  echo "usage: $0 NETWORK_INTERFACE(en0|en1)"
  exit 1
fi

interface="$1"
mac=`openssl rand -hex 1 | \
tr '[:lower:]' '[:upper:]' | \
xargs echo "obase=2;ibase=16;" | \
bc | cut -c1-6 | sed 's/$/00/' | \
xargs echo "obase=16;ibase=2;" | bc | \
sed "s/$/:$(openssl rand -hex 5 | sed 's/\(..\)/\1:/g; s/.$//' | tr '[:lower:]' '[:upper:]')/"`

echo "Setting link-level address for [$interface] to [$mac]"
sudo ifconfig $interface ether $mac