you-dont-need-pihole/update.sh

#!/bin/bash
# vi: et sts=4 sw=4 ts=4

set -e

WORKDIR=${0%/*}
CFG=$WORKDIR/update.cfg

# Config defaults
BACKUPSUFFIX=
BLOCKLIST=$WORKDIR/block.list
LIST_DIR=$WORKDIR/lists
OUT=()
URL=()
if [[ -f $CFG ]]; then
    . "$CFG"
fi

TEMP_DIR=$(mktemp -d -t "${0##*/}.XXXXXX")
cleanup() {
    rm -fr -- "$TEMP_DIR"
}
trap 'cleanup' EXIT

(cd "$WORKDIR" && git submodule update --init --remote)

for (( I = 0 ; I < ${#OUT[@]} ; ++I )); do
    MY_URL=${URL[$I]}
    MY_OUT=${OUT[$I]}
    if [[ -z $MY_URL ]]; then
        echo "$CFG: URL[$I] empty" >&2
        exit 2
    fi
    if [[ -z $MY_OUT ]]; then
        echo "$CFG: OUT[$I] empty" >&2
        exit 2
    fi

    TEMP_OUT=$(mktemp -p "$TEMP_DIR")

    if [[ -f $MY_OUT ]]; then
        cp -a -- "$MY_OUT" "$TEMP_OUT"
    fi

    wget \
        -O "$TEMP_OUT" \
        "$MY_URL"

    if [[ -f $MY_OUT ]]; then
        chmod --reference="$MY_OUT" "$TEMP_OUT"
        if [[ -n $BACKUPSUFFIX ]]; then
            mv -- "$MY_OUT" "$MY_OUT$BACKUPSUFFIX"
        fi
    fi

    mkdir -p -- "${MY_OUT%/*}"
    mv -- "$TEMP_OUT" "$MY_OUT"

    # If the old one is the same, don't keep it around
    if [[ -n $BACKUPSUFFIX && -f $MY_OUT$BACKUPSUFFIX ]]; then
        if diff -q "$MY_OUT" "$MY_OUT$BACKUPSUFFIX"; then
            rm -f -- "$MY_OUT$BACKUPSUFFIX"
        fi
    fi

done

if [[ -n $BACKUPSUFFIX && -f $BLOCKLIST ]]; then
    mv -- "$BLOCKLIST" "$BLOCKLIST$BACKUPSUFFIX"
fi
"$WORKDIR/make-block.pl" --out="$BLOCKLIST"

# If the old one is the same the same, don't keep it around
if [[ -n $BACKUPSUFFIX && -f $BLOCKLIST$BACKUPSUFFIX ]]; then
    if diff -q "$BLOCKLIST" "$BLOCKLIST$BACKUPSUFFIX"; then
        rm -f -- "$BLOCKLIST$BACKUPSUFFIX"
    fi
fi

if [[ -x /etc/rc.d/rc.dnsmasq ]]; then
    /etc/rc.d/rc.dnsmasq restart
fi