A simple bash script that can be used to fetch various DNS ad filter lists in either rpz or /etc/hosts format.

fetch-adlists-rpz.sh

#!/usr/bin/env bash

set -euo pipefail

fetch_hosts_as_rpz() {
    local action="${1?no action!}"
    local destination="${2?no destination!}"

    shift 2
    if [ $# = 0 ]
    then
        echo "No source URLs given!" >&2
        return 1
    fi

    local tmp_file="$destination.tmp"
    touch "$tmp_file"
    cat <<'EOL' > "$tmp_file"
$TTL 300
@ SOA localhost. root.localhost. 1714221973 43200 3600 259200 300
  NS  localhost.
EOL

    local tmp_download
    local status_code
    for source in "$@"
    do
        tmp_download="$(mktemp)"
        if ! status_code="$(curl -s -L -o "$tmp_download" -w "%{http_code}" "$source")" || [ "$status_code" != "200" ]
        then
            echo "Failed to fetch source $source, skipping entire list!" >&2
            echo "Response status: $status_code"
            echo "Output:"
            cat "$tmp_download"
            rm "$tmp_download" "$tmp_file"
            return 0
        fi
        grep -P '^\s*0\.0\.0\.0\s+' "$tmp_download" | sed -r 's/#.*$//g' | grep -Pv '\s+0\.0\.0\.0\s*$' | sed -r "s/^\s*0\.0\.0\.0\s+(\S+)/\1 300 IN CNAME $action/g" >> "$tmp_file"
        rm "$tmp_download"
    done

    mv "$tmp_file" "$destination"
}

fetch_rpz() {
    local destination="${1?no destination!}"
    local source="${2?no source!}"

    local tmp_file="$destination.tmp"
    local status_code
    status_code="$(curl -s -L -o "$tmp_file" -w "%{http_code}" "$source")"
    if [ "$status_code" = "200" ]
    then
        mv "$tmp_file" "$destination"
    else
        echo "Failed to fetch source $source, skipping list!" >&2
        echo "Response status: $status_code"
        echo "Output:"
        cat "$tmp_file"
        rm "$tmp_file"
    fi
}

# https://github.com/StevenBlack/hosts
fetch_hosts_as_rpz '.' /etc/knot-resolver/steven-black-hosts.rpz https://raw.githubusercontent.com/StevenBlack/hosts/master/alternates/fakenews-gambling/hosts
# https://github.com/badmojr/1Hosts
fetch_rpz /etc/knot-resolver/1hosts-lite.rpz https://o0.pages.dev/Lite/rpz.txt
# https://github.com/sjhgvr/oisd
fetch_rpz /etc/knot-resolver/osid.rpz https://big.oisd.nl/rpz