Script to check whether one ip/subnet is within another ip/subnet

checksubnet.sh

#!/bin/bash
(( $# != 2 )) && {
    echo "uso: ./$0 10.0.0.0/8 10.10.10.10/24"
    exit 1
}
IFS="/" read ip1 mask1 <<< $1
IFS="/" read ip2 mask2 <<< $2
size=$mask1
readarray -d'.' -t first <<< $ip1
readarray -d'.' -t second <<< $ip2

binary=({0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1})
zeroes=00000000000000000000000000000000
ones=11111111111111111111111111111111

mask2=$(echo ${ones::$mask2}${zeroes:$mask2}|sed 's/.\{8\}/\0./g'| sed 's/\.$//g')
mask1=$(echo ${ones::$mask1}${zeroes:$mask1}|sed 's/.\{8\}/\0./g'| sed 's/\.$//g')

readarray -d'.' -t firstmask <<< $mask1
readarray -d'.' -t secondmask <<< $mask2

for i in {0..3}; do
    answ=${binary[$(( 2#${firstmask[$i]} & 2#${secondmask[$i]} ))]}
    ((2#$answ == 2#${firstmask[$i]})) || {
        echo "$2 nao cabe em $1"
        exit 1;
    }
done

for i in {0..3}; do
    maior+=${binary[${first[$i]}]}
    menor+=${binary[${second[$i]}]}
done
(( ${maior::$size} == ${menor::$size} )) && echo "$2 cabe em $1" || echo "$2 nao cabe em $1"