dynv6.net updater

dynv6.sh

#!/usr/bin/env bash

# Usage: dynv6.sh --token TOKEN --name NAME1,NAME2
# Created by @ffflorian (https://github.com/ffflorian)
# Licensed under the MIT license.

SCRIPT_NAME="${0##*/}"

_print_usage() {
cat <<EOF
Usage: ${SCRIPT_NAME} [-h] [switch] [command] <NAME[,NAME2, ...]>

Commands:
 --help (-h)                      Show help text
 --name (-n) example.com          Set the update URL
              [,example2.com,...]
Switches:
 --token (-t) 3d3192b72...        Set the update token
 --quiet (-q)                     Display only errors
EOF
}

_command_exist() {
    command -v "${1}" > /dev/null
}

_log() {
    echo "${2}" "[$(date +'%Y-%m-%d %H:%M:%S')] ${1}"
}

while :
do
    case "$1" in
        -t|--token )
            TOKEN="${2}"
            shift 2
            ;;
        -n|--name )
            NAMES="${2}"
            shift 2
            ;;
        -h|--help )
            _print_usage
            exit 0
            ;;
        -q|--quiet )
            QUIET="quiet"
            shift 1
            ;;
        * )
            break
            ;;
    esac
done

if [[ -z "${TOKEN}" || -z "${NAMES}" ]]; then
    _print_usage
    exit 1
fi

if ! _command_exist dig; then
    _log "dig not found. Please install dnsutils."
    exit 1
fi

PUBLIC_IP="$(wget http://ipecho.net/plain -O - -q)"

if _command_exist curl; then
    BIN="curl -fsS"
elif _command_exist wget; then
    BIN="wget -qO-"
else
    _log "Neither wget nor curl found. Can not update."
    exit 1
fi

for NAME in ${NAMES//,/ }
do
    if grep -q '^[a-z0-9-]\{5,20\}$' <<< "${NAME}"; then
        NAME="${NAME}.dynv6.net"
    else
        if ! grep -q '^[a-z0-9-]\{5,20\}.dynv6.net$' <<< "${NAME}"; then
            _log "${NAME}: Invalid hostname!"
            exit 1
        fi
    fi

    IPFILE="${HOME}/.${NAME}.addr4"
    if [ -r "${IPFILE}" ] && [ "${PUBLIC_IP}" = "$(cat "${IPFILE}")" ]; then
        [ "${QUIET}" != "quiet" ] && _log "${NAME} is current."
        continue
    fi

    [ "${QUIET}" != "quiet" ] && _log "Updating ${NAME} ... " "-n"

    UPDATE_URL="http://ipv4.dynv6.com/api/update?hostname=${NAME}&ipv4=${PUBLIC_IP}&token=${TOKEN}"

    if [ "${QUIET}" = "quiet" ]; then
        ${BIN} "${UPDATE_URL}" > /dev/null && UPDATED="updated"
    else
        ${BIN} "${UPDATE_URL}" && UPDATED="updated"
    fi

    if [ "${UPDATED}" = "updated" ]; then
        echo "${PUBLIC_IP}" > "${IPFILE}"
    else
        _log "Update failed!"
        exit 1
    fi
done