use custom dns

check_ptr.sh

@@ -10,14 +10,16 @@ if [[ $# -ne 1 ]]; then
     exit 1
 fi
 
+DNS="84.2.44.1"
+
 # Get IPs
-IPS="$(dig +short $1 A | sort -u) $(dig +short $1 AAAA | sort -u)"
+IPS="$(dig +short $1 A @$DNS | sort -u) $(dig +short $1 AAAA @$DNS | sort -u)"
 
 # Loop through IPs
 fails=0
 for IP in $IPS; do
         # Performs the actual lookup against blacklists
-        RESULT=$(host $IP | rev | cut -d" " -f1 | rev | sed 's/.$//')
+        RESULT=$(host $IP $DNS | tail -1 | rev | cut -d" " -f1 | rev | sed 's/.$//')
         if [ "$RESULT" != "$1" ]; then
                 ((fails++))
         fi