Generate an ipset for a given autonomous system number

fetch-ipset-from-asn.bash

#!/bin/bash

usage()
{
        echo "Usage: $0 [ASN]"
}

if [ $# -ne 1 ]; then
        usage
        exit 1
fi
ASN="${1}"

input=$(curl -s 'https://asn.ipinfo.app/api/text/list/AS'"${ASN}")
linecount=$(wc -l <<< "${input}")

ipv4count=$(grep -Eco "([0-9.]+){4}/[0-9]{1,2}" <<< "${input}")
ipv6count=$(grep -Eco "([0-9a-f]+:){1,7}:/[0-9]{1,3}" <<< "${input}")
flag=0

if [ ${ipv4count} -gt 0 ]; then
        flag=1
        echo '/usr/sbin/ipset -N asn_'"${ASN}"'_v4 hash:net family inet'
        while read -r line; do
                echo '/usr/sbin/ipset -A asn_'"${ASN}"'_v4 '"${line}"
        done <<< "$(grep -E "([0-9.]+){4}/[0-9]{1,2}" <<< "${input}")"
fi
if [ ${ipv6count} -gt 0 ]; then
        flag=1
        echo '/usr/sbin/ipset -N asn_'"${ASN}"'_v6 hash:net family inet6'
        while read -r line; do
                echo '/usr/sbin/ipset -A asn_'"${ASN}"'_v6 '"${line}"
        done <<< "$(grep -E "([0-9a-f]+:){1,7}:/[0-9]{1,3}" <<< "${input}")"
fi
if [ ${flag} -eq 1 ]; then
        echo '/usr/sbin/ipset -N asn_'"${ASN}"' list:set'
        if [ ${ipv4count} -gt 0 ]; then
                echo '/usr/sbin/ipset -A asn_'"${ASN}"' asn_'"${ASN}"'_v4'
        fi
        if [ ${ipv6count} -gt 0 ]; then
                echo '/usr/sbin/ipset -A asn_'"${ASN}"' asn_'"${ASN}"'_v6'
        fi
fi