Improve whitelisting script

Match domain exactly instead of partially.
Gather list of domains to minimize number of times that hosts file must be enumerated.
Only add domain to whitelist if it isn't already present.

advanced/Scripts/whitelist.sh

@@ -1,13 +1,44 @@
 #!/bin/bash
+
+if [ $# = 0 ]; then
+    echo "Immediately whitelists one or more domains."
+    echo "Usage: whitelist.sh domain1 [domain2 ...]"
+fi
+
+combopattern=""
+
 # For each argument passed to this script
 for var in "$@"
 do
-        echo "Whitelisting $var..."
-        # Use sed to search for the domain in /etc/pihole/gravity.list and remove it using an in-place edit
-        sed -i "/$var/d" /etc/pihole/gravity.list
-        # Also add the domain to the whitelist.txt in /etc/pihole
-        echo "$var" >> /etc/pihole/whitelist.txt
+  echo "Whitelisting $var..."
+
+  # Construct basic pattern to match domain name.
+  basicpattern=$(echo $var | awk -F '[# \t]' 'NF>0&&$1!="" {print ""$1""}' | sed 's/\./\\./g')
+
+  if [ "$basicpattern" != "" ]; then
+    # Add to the combination pattern that will be used below
+    if [ "$combopattern" != "" ]; then combopattern="$combopattern|"; fi
+    combopattern="$combopattern$basicpattern"
+
+    # Also add the domain to the whitelist but only if it's not already present
+    grep -E -q "^$basicpattern$" /etc/pihole/whitelist.txt \
+    || echo "$var" >> /etc/pihole/whitelist.txt
+  fi
 done
-echo "** $# domain(s) whitelisted."
-# Force dnsmasq to reload /etc/pihole/gravity.list
-kill -HUP $(pidof dnsmasq)
+
+# Now report on and remove matched domains
+if [ "$combopattern" != "" ]; then
+  echo "Modifying hosts file..."
+  
+  # Construct pattern to match entry in hosts file.
+  # This consists of one or more IP addresses followed by the domain name.
+  pattern=$(echo $combopattern | awk -F '[# \t]' '{printf "%s", "^(([0-9]+\.){3}[0-9]+ +)+("$1")$"}')
+
+  # Output what will be removed and then actually remove
+  sed -r -n 's/'"$pattern"'/  Removed: \3/p' /etc/pihole/gravity.list
+  sed -r -i '/'"$pattern"'/d' /etc/pihole/gravity.list
+
+  echo "** $# domain(s) whitelisted."
+  # Force dnsmasq to reload /etc/pihole/gravity.list
+  kill -HUP $(pidof dnsmasq)
+fi