Bash script that I run in cron that emails me every time my Slicehost VMs get added back in to the Spamhaus PBL.

spamhaus_check.sh

#!/bin/bash

usage()
{
cat << EOF
usage: $0 <ip> [blocklist]

ip         The IP to check.
blocklist  The Spamhaus block list to check. Defaults to zen but can be one of these: zen, sbl, xbl, pbl or dbl. 
EOF
}

if [ -z "$1" ]; then
	usage
	exit
fi
IP_ADDR=$1

if [ -z "$2" ]; then 
	BLOCK_LIST=zen
else
	BLOCK_LIST="$2"
fi


IFS='.'; read -ra ADDR <<< "$IP_ADDR"
REVERSE_ADDR=""
for i in "${ADDR[@]}"; do
	if [ -z "$REVERSE_ADDR" ]; then
		REVERSE_ADDR="${i}"
	else
		REVERSE_ADDR="${i}.${REVERSE_ADDR}"
	fi
done

OUTPUT=`host "${REVERSE_ADDR}.${BLOCK_LIST}.spamhaus.org"`
if [[ "$OUTPUT" =~ "has address" ]]; then
	echo "${IP_ADDR} is in the ${BLOCK_LIST} Spamhaus block list"
fi