Shell script for an up-to-date Ad-Free /etc/hosts

#!/bin/bash
# Update Ad-Free /etc/hosts file from public lists
# Original found on http://korovamilky.tumblr.com/
readonly TMP_FILE="/tmp/hosts"
readonly HOSTS_FILE="/etc/hosts"
# WINDOWS HOSTS FILE: %systemroot%\system32\drivers\etc\hosts

touch ${TMP_FILE}

for URL in  http://adaway.org/hosts.txt \
            http://winhelp2002.mvps.org/hosts.txt \
            http://someonewhocares.org/hosts/hosts \
            http://pgl.yoyo.org/adservers/serverlist.php?hostformat=hosts\&showintro=0\&mimetype=plaintext
do curl -s ${URL} | egrep "^127.0.0.1|^0.0.0.0" >> ${TMP_FILE}
done

# remember to add here your custom known hosts:
echo "127.0.0.1 localhost
127.0.0.1 localhost.localdomain
fe80::1%lo0 localhost
255.255.255.255 broadcasthost
" > ${HOSTS_FILE}

# use 0.0.0.0 instead of 127.0.0.1 (faster but not 100% compatible)
awk '!/ localhost/'{'print "0.0.0.0 "$2'} ${TMP_FILE} | sort | uniq >> ${HOSTS_FILE}
rm -f ${TMP_FILE}

exit 0