#!/bin/bash

# snippet from https://stackoverflow.com/questions/10768160/ip-address-converter
ip2dec () {
    local a b c d ip=$@
    IFS=. read -r a b c d <<< "$ip"
    printf '%d\n' "$((a * 256 ** 3 + b * 256 ** 2 + c * 256 + d))"
}

# This only works with real bash (<<<) - split IP addresses into array with
# hyphen as delimiter
readarray -d - -t strarr <<< $1

ipaddrcheck --is-ipv4-single ${strarr[0]}
if [ $? -gt 0 ]; then
  exit 1
fi

ipaddrcheck --is-ipv4-single ${strarr[1]}
if [ $? -gt 0 ]; then
  exit 1
fi

start=$(ip2dec ${strarr[0]})
stop=$(ip2dec ${strarr[1]})
if [ $start -ge $stop ]; then
  exit 1
fi

exit 0