#!/bin/bash
if (( $EUID != 0 )); then
   echo "This must be run as root. Try 'sudo bash $0'."
   exit 1
fi

echo "Swap wlan0 and wlan1"
IFACE=wlan0
read MAC </sys/class/net/$IFACE/address

if ! [ -f /etc/udev/rules.d/70-my_network_interfaces.rules ]
then
echo "file not exist => install it.."
echo ""
else
echo "file exist => remove it and install it again..."
echo ""
rm /etc/udev/rules.d/70-my_network_interfaces.rules
fi
cat <<'EOF'>> /etc/udev/rules.d/70-my_network_interfaces.rules
# Built-in wifi interface used in hostapd - identify device by MAC address
SUBSYSTEM=="net", ACTION=="add", ATTR{address}=="XXX", NAME="wlan1"
EOF

sudo sed -i -e "s/XXX/$MAC/g" /etc/udev/rules.d/70-my_network_interfaces.rules

echo "Actuel wlan0 MAC address is : $MAC"
echo "After reboot wlan0 will swapped to wlan1 and wlan1 to wlan0"
echo "check the config file and double check is what you want:"
echo ""
cat /etc/udev/rules.d/70-my_network_interfaces.rules
echo ""
echo "if it's ok, reboot...otherwize edit the file /etc/udev/rules.d/70-my_network_interfaces.rules"
echo