VPN Kill Switch For MacOS |Terminal User Interface | Route(8)

killswitch.command

#! /bin/bash

echo off

defgw=$(route get 0.0.0.0 2>/dev/null | awk '/gateway: / {print $2}';)
def_int=$(route get 0.0.0.0 2>/dev/null | awk '/interface: / {print $2}';)

clear
:start
clear

echo Simple VPN KillSwitch, ver. 1.1 - by whoami
echo
echo Your default gateway is "$defgw" on interface "$def_int"
echo "-if nothing appears or its incorrect, add it manually (Press "4")"
echo
echo USAGE: 
echo
PS3='Please enter your choice: '
options=("Manually insert VPN IP" "Enable Kill Switch (IP "$defgw")" "Disable Kill Switch (IP "$defgw")" "Manually set default gateway if its not detected above." "Exit Kill Switch")
select opt in "${options[@]}"
do
    case $opt in
     "Manually insert VPN IP")
            echo -n "Enter you VPN IP and press [ENTER]: "
read vpn
echo VPN $vpn Configured...
sleep 2
 ;;
    "Enable Kill Switch (IP "$defgw")")
            sudo route -n add $vpn $defgw 255.255.255.255 -static
            sudo route -n delete default default -ifp $def_int -ifa 192.168.0.24
            echo Kill Switch Enabled...
sleep 1
;;
    "Disable Kill Switch (IP "$defgw")")
            sudo route -n delete $vpn $defgw 255.255.255.255 -static 
            sudo route -n add default $defgw default -ifp $def_int -ifa 192.168.0.24
            echo Kill Switch Disabled...
sleep 1 
;;
    "Manually set default gateway if its not detected above.")
            echo -n "Enter Default Gateway IP and press [ENTER]: "
read defgw 
echo Default Gateway $defgw Configured...       
;;
    "Exit Kill Switch")                
             break
            ;;
        *) echo "invalid option $REPLY";;
    esac
done