get_vpn_ip

get_vpn_ip

[get_my_vpn_ip.sh]
#!/bin/bash

last_ip_file="/some/path/vpn/last_ip"
log_file="/some/path/vpn/vpn_ip.log"

if [ -e $last_ip_file ]
then
  last_ip=$(cat /some/path/vpn/last_ip)
  current_ip=$(/some/path/vpn/vpn_ip.sh)
  if [ $? -eq 0 ]
  then
    if [ "$last_ip" != "$current_ip" ]
    then
      /some/path/vpn/vpn_ip.sh > /some/path/vpn/last_ip
      now=$(date "+%s")
      echo -ne "$now,$last_ip,$current_ip\n" > $log_file
      exit 0
    fi
  fi
  exit 1
fi

===
[get_my_vpn_ip.sh]
#!/bin/bash
# Get IP of tunnel(tun0) if it is up.

is_tunnel_up() {
  /sbin/ifconfig tun0 2>&1 >/dev/null
  if [ $? -eq 0 ]
  then
    return 0
  fi
  return 1
}

get_vpn_ip() {
  is_tunnel_up
  if [ $? -ne 0 ]
  then
    return 1
  fi
  vpn_ip=$(/sbin/ifconfig tun0|grep "inet add"|cut -d: -f2|cut -d" " -f1)
  echo $vpn_ip
  return 0
}

main() {
  vpn_ip=$(get_vpn_ip)
  if [ $? -ne 0 ]
  then
    exit 1
  fi 
  echo $vpn_ip
  exit 0
}

main