[OpenTTD] xUSSR Set updater

#!/bin/bash

# The MIT License (MIT)

# Copyright (c) 2017 mcmodder

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# This script will download latest xUSSR Set version.
# Used files: .xussr.ver with current xUSSR Set version; xussr.tar with xUSSR Set, both in ~/.openttd/newgrf

_NEWGRF_PATH="$HOME/.openttd/newgrf/"
[ ! -e "${_NEWGRF_PATH}xussr.tar" ] && rm -f "${_NEWGRF_PATH}.xussr.ver"

_VERSION_DATA=$(curl -sL http://bundles.openttdcoop.org/xussrset/push/LATEST/custom_tags.txt)
_XUSSR_REMOTE=$( grep NEWGRF_VERSION <<<"$_VERSION_DATA" | cut -f2 -d':' )
_XUSSR_DATE=$( grep REPO_DATE <<<"$_VERSION_DATA" | cut -f2 -d':' )
_XUSSR_INSTALLED=$(<"${_NEWGRF_PATH}.xussr.ver") 2>/dev/null && echo "Installed xUSSR Set version: r${_XUSSR_INSTALLED}"
echo "Latest xUSSR Set version: r$_XUSSR_REMOTE"

[ ! -e "${_NEWGRF_PATH}xussr.tar" ] && _XUSSR_INSTALLED=""
if [ "${_XUSSR_INSTALLED}" != "${_XUSSR_REMOTE}" ]; then
  echo "Downloading xUSSR Set r${_XUSSR_REMOTE}..."
  curl -qL "http://bundles.openttdcoop.org/xussrset/push/LATEST/xussr-r${_XUSSR_REMOTE}.zip" | funzip > "${_NEWGRF_PATH}xussr.tar"
  echo "${_XUSSR_REMOTE}" > "${_NEWGRF_PATH}.xussr.ver"
  echo "Downloaded xUSSR Set r${_XUSSR_REMOTE} (released ${_XUSSR_DATE})"
  echo "View changelog at http://dev.openttdcoop.org/projects/xussrset/repository/changes"
else
  echo "Nothing to do"
fi