maketorblocklist.sh fixups

installer/resources/maketorblocklist.sh

@@ -6,80 +6,100 @@
 
 # Adapted from I2P+, license granted to I2P under I2P license
 
+set -eu    # abort on error or undefined variable
+
+cd "$(dirname "$0")" # change to resources/installer
+
 # Specify input, output, and proxy variables
 input_file="torbulkexitlist"
+download_file="$(mktemp)"
+trap "rm -fv ""$download_file""" EXIT  # intentional double-quoting
 output_file="blocklist-tor.txt"
-http_proxy=${http_proxy:-"http://127.0.0.1:4444"}
+http_proxy="${http_proxy:-http://127.0.0.1:4444}"
 
 # Variables
-url="https://check.torproject.org/$input_file"
+url=https://check.torproject.org/"$input_file"
 today="$(date '+%d %B %Y')"
 
-# Check if curl is installed
-if [ -z "$(which curl)" ]; then
-  echo "> curl is not installed. Please install curl to use this script."
+# Check if curl is installed using a Bourne-compatible shell built-in
+if ! command -v curl > /dev/null 2>&1;  then
+  echo "> curl is not installed. Please install curl to use this script." >&2
   exit 1
 fi
 
-# Remove existing input file if it exists
-if [ -f $input_file ]; then
-  rm $input_file
-  echo " > Deleted existing local copy of $input_file"
-fi
-
 # Download the latest list from Tor Project
-echo " > Downloading the latest list from Tor Project via specified proxy $http_proxy..."
-curl -o $input_file -x $http_proxy $url 2>/dev/null
-if [ $? -ne 0 ]; then
-  echo " > Failed to download the latest list using proxy ${http_proxy}. Please check your proxy settings and try again."
+echo " > Downloading the latest list from Tor Project via specified proxy $http_proxy..." >&2
+if ! curl --silent -o "$download_file" -x "$http_proxy" "$url" ; then
+  echo " > Failed to download the latest list using proxy ${http_proxy}. Please check your proxy settings and try again." >&2
   exit 1
 fi
 
 # Count the number of IPs in the file
-ips_count=$(wc -l $input_file)
-echo " > Number of IPs in $input_file: $ips_count"
-echo " > Sorting IPs and consolidating ranges, please stand by..."
+ips_count=$(wc -l < "$download_file")  # using the redirect prevents the filename from being output
+echo " > Number of IPs in $input_file: $ips_count" >&2
+echo " > Sorting IPs and consolidating ranges, please stand by..." >&2
 
 # Sort the list of IPs naturally
-sorted_ips=$(cat $input_file | sort -V)
+# The version sort -V will usually do the right thing, but this is explicitly for IP addresses,
+# ensuring that each octet is sorted with every version of `sort`.
+sorted_ips=$(sort -t . -k1,1n -k2,2n -k3,3n -k4,4n "$download_file")
 
 # Initialize variables
 start_ip=""
 end_ip=""
 
-cp $output_file ${output_file}.bak
+[ -r "$output_file" ] && cp "$output_file" "${output_file}".bak
 
 # Print URL and date to the output file
-echo "# $url" > $output_file
-echo "# $today" >> $output_file
+echo "# $url" > "$output_file"
+echo "# $today" >> "$output_file"
 
 # Function to print the IP range
 print_range() {
   if [ "$start_ip" = "$end_ip" ]; then
-    echo "$start_ip" >> $output_file
+    echo "$start_ip" >> "$output_file"
   else
-    echo "${start_ip}-${end_ip}" >> $output_file
+    echo "${start_ip}-${end_ip}" >> "$output_file"
   fi
 }
 
+# Function to increment the last octet of an IPv4 IP address
+increment_ip() {
+  ip="$1"
+  a=${ip%.*.*.*}
+  b="${ip#*.}"; b="${b%.*.*}"
+  c="${ip#*.*.}"; c="${c%.*}"
+  d="${ip##*.}"
+  d="$((d + 1))"
+  if [ "$d" -eq 256 ]; then
+    d=0
+    c=$((c + 1))
+    if [ "$c" -eq 256 ]; then
+      c=0
+      b=$((b + 1))
+      if [ "$b" -eq 256 ]; then
+        b=0
+        a=$((a + 1))
+      fi
+    fi
+  fi
+  echo "$a.$b.$c.$d"
+}
+
 # Loop through the sorted IPs to find consecutive IPs
 for ip in $sorted_ips; do
-  if [ "$start_ip" = "" ]; then
-    start_ip=$ip
-  elif [ "$ip" != $(echo -n "$end_ip" | awk -F. '{ printf "%d.%d.%d.%d", $1, $2, $3, $4 + 1}') ]; then
+  if [ -z "$start_ip" ]; then
+    start_ip="$ip"
+  elif [ "$ip" != "$(increment_ip "$end_ip")" ]; then
     print_range
-    start_ip=$ip
+    start_ip="$ip"
   fi
-  end_ip=$ip
+  end_ip="$ip"
 done
 
 # Print the last range
 print_range
 
-echo " > Consolidated IPs saved to: $output_file"
-ips_count=$(wc -l $output_file)
-echo " > Consolidated IP ranges in $output_file: $(($ips_count - 2))"
-
-# Clean up: Remove downloaded input file
-rm $input_file
-echo " > Deleted $input_file"
+echo " > Consolidated IPs saved to: $output_file" >&2
+ips_count=$(wc -l < "$output_file")
+echo " > Consolidated IP ranges in $output_file: $((ips_count - 2))" >&2