Install script now saves interface and IPv4 address to files in /etc/pihole rather than /tmp.

gravity.sh, blacklist.sh, whitelist.sh read from these files first.  If they cannot find them then they warn the user and detect and use the most sensible interface / IPv4 address.
gravity.sh no longer deletes the IPv4 file.

advanced/Scripts/blacklist.sh

@@ -34,13 +34,31 @@ domList=()
 domToRemoveList=()
 
 
-piholeIPfile=/tmp/piholeIP
+piholeINTfile=/etc/pihole/piholeINT
+piholeIPfile=/etc/pihole/piholeIP
 piholeIPv6file=/etc/pihole/.useIPv6
 
-# 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
+# Know which interface we are using.
+if [[ -f $piholeINTfile ]]; then
+    # This file should normally exist - it was saved as part of the install.
+    IPv4dev=$(cat $piholeINTfile)
+else
+    # If it doesn't, we err on the side of working with the majority of setups and detect the most likely interface.
     IPv4dev=$(ip route get 8.8.8.8 | awk '{for(i=1;i<=NF;i++)if($i~/dev/)print $(i+1)}')
-piholeIPCIDR=$(ip -o -f inet addr show dev $IPv4dev | awk '{print $4}' | awk 'END {print}')
+    echo "::: Warning: ${piholeINTfile} is missing.  Using interface ${IPv4dev}."
+fi
+
+# Know which IPv4 address we are using.
+if [[ -f $piholeIPfile ]];then
+    # This file should normally exist - it was saved as part of the install.
+    piholeIP=$(cat $piholeIPfile)
+else
+    # If it doesn't, we err on the side of working with the majority of setups and detect the most likely IPv4 address,
+    # which is the first one we find belonging to the given interface.
+    piholeIPCIDR=$(ip -o -f inet addr show dev $IPv4dev | awk '{print $4}' | head -n 1)
     piholeIP=${piholeIPCIDR%/*}
+    echo "::: Warning: ${piholeIPfile} is missing.  Using IPv4 address ${piholeIP}."
+fi
 
 modifyHost=false
 

advanced/Scripts/whitelist.sh

@@ -33,13 +33,31 @@ versbose=true
 domList=()
 domToRemoveList=()
 
-piholeIPfile=/tmp/piholeIP
+piholeINTfile=/etc/pihole/piholeINT
+piholeIPfile=/etc/pihole/piholeIP
 piholeIPv6file=/etc/pihole/.useIPv6
 
-# 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
+# Know which interface we are using.
+if [[ -f $piholeINTfile ]]; then
+    # This file should normally exist - it was saved as part of the install.
+    IPv4dev=$(cat $piholeINTfile)
+else
+    # If it doesn't, we err on the side of working with the majority of setups and detect the most likely interface.
     IPv4dev=$(ip route get 8.8.8.8 | awk '{for(i=1;i<=NF;i++)if($i~/dev/)print $(i+1)}')
-piholeIPCIDR=$(ip -o -f inet addr show dev $IPv4dev | awk '{print $4}' | awk 'END {print}')
+    echo "::: Warning: ${piholeINTfile} is missing.  Using interface ${IPv4dev}."
+fi
+
+# Know which IPv4 address we are using.
+if [[ -f $piholeIPfile ]];then
+    # This file should normally exist - it was saved as part of the install.
+    piholeIP=$(cat $piholeIPfile)
+else
+    # If it doesn't, we err on the side of working with the majority of setups and detect the most likely IPv4 address,
+    # which is the first one we find belonging to the given interface.
+    piholeIPCIDR=$(ip -o -f inet addr show dev $IPv4dev | awk '{print $4}' | head -n 1)
     piholeIP=${piholeIPCIDR%/*}
+    echo "::: Warning: ${piholeIPfile} is missing.  Using IPv4 address ${piholeIP}."
+fi
 
 modifyHost=false
 

automated install/basic-install.sh

@@ -152,7 +152,6 @@ chooseInterface() {
 		do
 		piholeInterface=$desiredInterface
 		echo "::: Using interface: $piholeInterface"
-		echo ${piholeInterface} > /tmp/piholeINT
 		done
 	else
 		echo "::: Cancel selected, exiting...."
@@ -219,6 +218,9 @@ use4andor6() {
 										Gateway:         $IPv4gw" $r $c)
 			then
 				echo "::: Leaving IPv4 settings as is."
+				# Saving the IP and interface to a file for future use by other scripts (gravity.sh, whitelist.sh, etc.)
+				echo ${IPv4addr%/*} > /etc/pihole/piholeIP
+				echo $piholeInterface > /etc/pihole/piholeINT
 			else
 				getStaticIPv4Settings
 				setStaticIPv4
@@ -284,9 +286,9 @@ getStaticIPv4Settings() {
 							IP address:    $IPv4addr
 							Gateway:       $IPv4gw" $r $c)then
 							# If the settings are correct, then we need to set the piholeIP
-							# Saving it to a temporary file us to retrieve it later when we run the gravity.sh script
+							# Saving the IP and interface to a file for future use by other scripts (gravity.sh, whitelist.sh, etc.)
-							echo ${IPv4addr%/*} > /tmp/piholeIP
+							echo ${IPv4addr%/*} > /etc/pihole/piholeIP
-							echo $piholeInterface > /tmp/piholeINT
+							echo $piholeInterface > /etc/pihole/piholeINT
 							# After that's done, the loop ends and we move on
 							ipSettingsCorrect=True
 					else

gravity.sh

@@ -26,7 +26,8 @@ else
   fi
 fi
 
-piholeIPfile=/tmp/piholeIP
+piholeINTfile=/etc/pihole/piholeINT
+piholeIPfile=/etc/pihole/piholeIP
 piholeIPv6file=/etc/pihole/.useIPv6
 
 adListFile=/etc/pihole/adlists.list
@@ -34,15 +35,26 @@ adListDefault=/etc/pihole/adlists.default
 whitelistScript=/usr/local/bin/whitelist.sh
 blacklistScript=/usr/local/bin/blacklist.sh
 
-if [[ -f $piholeIPfile ]];then
+# Know which interface we are using.
-    # 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
+if [[ -f $piholeINTfile ]]; then
-    piholeIP=$(cat $piholeIPfile)
+    # This file should normally exist - it was saved as part of the install.
-    rm $piholeIPfile
+    IPv4dev=$(cat $piholeINTfile)
 else
-    # Otherwise, the IP address can be taken directly from the machine, which will happen when the script is run by the user and not the installation script
+    # If it doesn't, we err on the side of working with the majority of setups and detect the most likely interface.
     IPv4dev=$(ip route get 8.8.8.8 | awk '{for(i=1;i<=NF;i++)if($i~/dev/)print $(i+1)}')
-    piholeIPCIDR=$(ip -o -f inet addr show dev $IPv4dev | awk '{print $4}' | awk 'END {print}')
+    echo "::: Warning: ${piholeINTfile} is missing.  Using interface ${IPv4dev}."
+fi
+
+# Know which IPv4 address we are using.
+if [[ -f $piholeIPfile ]];then
+    # This file should normally exist - it was saved as part of the install.
+    piholeIP=$(cat $piholeIPfile)
+else
+    # If it doesn't, we err on the side of working with the majority of setups and detect the most likely IPv4 address,
+    # which is the first one we find belonging to the given interface.
+    piholeIPCIDR=$(ip -o -f inet addr show dev $IPv4dev | awk '{print $4}' | head -n 1)
     piholeIP=${piholeIPCIDR%/*}
+    echo "::: Warning: ${piholeIPfile} is missing.  Using IPv4 address ${piholeIP}."
 fi
 
 if [[ -f $piholeIPv6file ]];then