MAC Spoofing script for Ubuntu 16.04

MAC_changer.sh

#!/bin/bash

if [ "$(id -u)" != "0" ]; then
  exec sudo "$0" "$@"
fi

change_mac() {
  echo -n "Choose network interface. (enp4s0f2): "
  read nic
  ifconfig $nic down
  ifconfig $nic hw ether $1
  ifconfig $nic up
  dhclient $nic
}

echo -n "Have you used this MAC address before? (yes/no): "
read method

if [ $method = yes ]; then
  cat -n name.txt
  echo -n "Please choose PC based on its corresponding number: "
  read old_mac_select
  old_mac=$(sed -n "${old_mac_select}p" ./mac.txt)
  echo "Selected MAC: $old_mac"
  change_mac $old_mac
else
  echo -n "Please enter name of PC for later use for MAC Spoofing: "
  read new_name
  echo $new_name >> ./name.txt
  echo -n "Please enter MAC address. (aa:bb:cc:11:22:33): "
  read new_mac
  echo $new_mac >> ./mac.txt
  change_mac $new_mac
fi

ping -c 5 8.8.8.8