#!/usr/bin/env bash

# @example
# chmod a+x randommac.sh
# ./randommac.sh wlp2s0

# Came from here: https://gist.github.com/WebReflection/67245d3e05a04299e6cf89df22685081

if [ "$1" != "" ]; then
  if [ "$(ip link show | grep $1)" != "" ]; then
    if [ ! -f ~/mac-address-$1.bck ]; then
      echo "storing original information in ~/mac-address-$1.bck"
      ip link show $1 > ~/mac-address-$1.bck
    fi
    sudo ip link set dev $1 down
    sudo ip link set dev $1 address $(openssl rand -hex 6 | sed 's/\(..\)/\1:/g; s/.$//')
    sudo ip link set dev $1 up
  else
    echo "unknown interface $1"
    echo "available interfaces:"
    ip link show | sed 's/^\([0-9]*:\s*\w*\):.*$/\1/g; s/^\s\s*.*$//g'
    exit 1
  fi
else
  echo "you need to specify an interface"
  echo "example: $0 wlp2s0"
  exit 1
fi
