Refactor

#!/usr/bin/env bash

set -eu

IMG="/storage"

[ ! -d "$IMG" ] && echo "Storage folder (${IMG}) not found!" && exit 69

if [ -z $URL ]; then

  if [ -f "$IMG"/dsm.ver ]; then

    BASE=$(cat "${IMG}/dsm.ver")

  else

    # Fallback for old installs

    BASE="DSM_VirtualDSM_42962"

  fi

else

  BASE=$(basename "$URL" .pat)

fi

[ ! -f "/run/server.sh" ] && echo "Script must run inside Docker container!" && exit 60

[ ! -f "$IMG/$BASE.boot.img" ] && rm -f "$IMG"/"$BASE".system.img

[ -f "$IMG/$BASE.system.img" ] && return

# Display wait message on port 5000

/run/server.sh 5000 > /dev/null &

  #URL="https://global.synologydownload.com/download/DSM/release/7.0.1/42218/DSM_VirtualDSM_42218.pat"

  #URL="https://global.synologydownload.com/download/DSM/release/7.1.1/42962-1/DSM_VirtualDSM_42962.pat"

  BASE=$(basename "$URL" .pat)

fi

BASE=$(basename "$URL" .pat)

echo "Install: Downloading extractor..."

TMP="$IMG/tmp"