Start code refactor, eliminate some repetitive code

Begin code refactor prepatation, prevent DRY where possible.

gravity.sh

@@ -1,11 +1,18 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # http://pi-hole.net
 # Compiles a list of ad-serving domains by downloading them from multiple sources
-
+piholeIPfile=/tmp/piholeIP
-# This script should only be run after you have a static IP address set on the Pi
+if [[ -f $piholeIPfile ]];then
-piholeIP=$(hostname -I)
+    # If the file exists, it means it was exported from the installation script and we should use that value instead of detecting it in this script
+    piholeIP=$(cat $piholeIPfile)
+    rm $piholeIPfile
+else
+    # Otherwise, the IP address can be taken directly from the machine, which will happen when the script is run by the user and not the installation script
+    piholeIP=$(ip -4 addr show | awk '{match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/); ip = substr($0,RSTART,RLENGTH); print ip}' | sed '/^\s*$/d' | grep -v "127.0.0.1" | (head -n1))
+fi
 
 # Ad-list sources--one per line in single quotes
+# The mahakala source is commented out due to many users having issues with it blocking legitimate domains.  Uncomment at your own risk
 sources=('https://adaway.org/hosts.txt'
 'http://adblock.gjtech.net/?format=unix-hosts'
 #'http://adblock.mahakala.is/'
@@ -16,19 +23,19 @@ sources=('https://adaway.org/hosts.txt'
 'http://winhelp2002.mvps.org/hosts.txt')
 
 # Variables for various stages of downloading and formatting the list
-adList=/etc/pihole/gravity.list
+basename=pihole
-origin=/etc/pihole
+piholeDir=/etc/$basename
-piholeDir=/etc/pihole
+adList=$piholeDir/gravity.list
-justDomainsExtension=domains
-matter=pihole.0.matter.txt
-andLight=pihole.1.andLight.txt
-supernova=pihole.2.supernova.txt
-eventHorizon=pihole.3.eventHorizon.txt
-accretionDisc=pihole.4.accretionDisc.txt
-eyeOfTheNeedle=pihole.5.wormhole.txt
 blacklist=$piholeDir/blacklist.txt
 whitelist=$piholeDir/whitelist.txt
-latentWhitelist=$origin/latentWhitelist.txt
+latentWhitelist=$piholeDir/latentWhitelist.txt
+justDomainsExtension=domains
+matter=$basename.0.matter.txt
+andLight=$basename.1.andLight.txt
+supernova=$basename.2.supernova.txt
+eventHorizon=$basename.3.eventHorizon.txt
+accretionDisc=$basename.4.accretionDisc.txt
+eyeOfTheNeedle=$basename.5.wormhole.txt
 
 # After setting defaults, check if there's local overrides
 if [[ -r $piholeDir/pihole.conf ]];then
@@ -53,7 +60,7 @@ do
         domain=$(echo "$url" | cut -d'/' -f3)
 
         # Save the file as list.#.domain
-	saveLocation=$origin/list.$i.$domain.$justDomainsExtension
+        saveLocation=$piholeDir/list.$i.$domain.$justDomainsExtension
 
         agent="Mozilla/10.0"
 
@@ -64,75 +71,26 @@ do
         case "$domain" in
                 "adblock.mahakala.is")
                         agent='Mozilla/5.0 (X11; Linux x86_64; rv:30.0) Gecko/20100101 Firefox/30.0'
-			cmd="curl -e http://forum.xda-developers.com/"
+                        cmd_ext="-e http://forum.xda-developers.com/"
                         ;;
 
                 "pgl.yoyo.org")
-			cmd="curl -d mimetype=plaintext -d hostformat=hosts"
-			;;
-
-		# Default is a simple curl request
-		*) cmd="curl"
-	esac
-
-	# tmp file, so we don't have to store the (long!) lists in RAM
-	patternBuffer=$(mktemp)
-	heisenbergCompensator=""
-	if [[ -r $saveLocation ]]; then
-		heisenbergCompensator="-z $saveLocation"
-	fi
-	CMD="$cmd -s $heisenbergCompensator -A '$agent' $url > $patternBuffer"
-	$cmd -s $heisenbergCompensator -A "$agent" $url > $patternBuffer
-
-
-	if [[ -s "$patternBuffer" ]];then
-		# Remove comments and print only the domain name
-		# Most of the lists downloaded are already in hosts file format but the spacing/formating is not contigious
-		# This helps with that and makes it easier to read
-		# It also helps with debugging so each stage of the script can be researched more in depth
-		awk '($1 !~ /^#/) { if (NF>1) {print $2} else {print $1}}' $patternBuffer | \
-			sed -nr -e 's/\.{2,}/./g' -e '/\./p' > $saveLocation
-		echo "Done."
-	else
-		echo "Skipping pattern because transporter logic detected no changes..."
-	fi
-
-	# Cleanup
-	rm -f $patternBuffer
-done
-
-# Find all files with the .domains extension and compile them into one file and remove CRs
-echo "** Aggregating list of domains..."
-find $origin/ -type f -name "*.$justDomainsExtension" -exec cat {} \; | tr -d '\r' > $origin/$matter
-
-# Append blacklist entries if they exist
-if [[ -r $blacklist ]];then
-	numberOf=$(cat $blacklist | sed '/^\s*$/d' | wc -l)
-	echo "** Blacklisting $numberOf domain(s)..."
-	cat $blacklist >> $origin/$matter
-fi
-
-###########################
-function gravity_advanced() {
-
-	numberOf=$(wc -l < $origin/$andLight)
         echo "** $numberOf domains being pulled in by gravity..."
 
         # Remove carriage returns and preceding whitespace
         # not really needed anymore?
-	cp $origin/$andLight $origin/$supernova
+        cp $piholeDir/$andLight $piholeDir/$supernova
 
         # Sort and remove duplicates
-	sort -u  $origin/$supernova > $origin/$eventHorizon
+        sort -u  $piholeDir/$supernova > $piholeDir/$eventHorizon
-	numberOf=$(wc -l < $origin/$eventHorizon)
+        numberOf=$(wc -l < $piholeDir/$eventHorizon)
         echo "** $numberOf unique domains trapped in the event horizon."
 
         # Format domain list as "192.168.x.x domain.com"
         echo "** Formatting domains into a HOSTS file..."
-	awk '{print "'"$piholeIP"'" $1}' $origin/$eventHorizon > $origin/$accretionDisc
+        cat $piholeDir/$eventHorizon | awk '{sub(/\r$/,""); print "'"$piholeIP"' " $0}' > $piholeDir/$accretionDisc
-
         # Copy the file over as /etc/pihole/gravity.list so dnsmasq can use it
-	sudo cp $origin/$accretionDisc $adList
+        sudo cp $piholeDir/$accretionDisc $adList
         kill -HUP $(pidof dnsmasq)
 }
 
@@ -160,6 +118,6 @@ do
 done
 
 # Remove whitelist entries from deduped list
-grep -vxf $latentWhitelist $origin/$matter > $origin/$andLight
+grep -vxf $latentWhitelist $piholeDir/$matter > $piholeDir/$andLight
 
 gravity_advanced