Fix tail command and remove unnecessary echo

dyndns.sh

@@ -33,20 +33,34 @@ while ( true ); do
         ip="$(curl -s $service | grep '[0-9]\{1,3\}\(\.[0-9]\{1,3\}\)\{3\}')"
         test -n "$ip" && break
     done
-    
+
     echo "Found IP address $ip"
 
     if [[ -n $ip ]]; then
         # disable glob expansion
         set -f
-		
+
         for sub in ${NAME//;/ }; do
             record_id=$(echo $domain_records| jq ".domain_records[] | select(.type == \"A\" and .name == \"$sub\") | .id")
             record_data=$(echo $domain_records| jq -r ".domain_records[] | select(.type == \"A\" and .name == \"$sub\") | .data")
-            
+
+            if [ $(echo "$record_id" | wc -l) -ge 2 ]; then :
+                echo "'$sub' domain name has duplicate DNS records, removing duplicates"
+                record_id_to_delete=$(echo "$record_id"| tail -n +2)
+                record_id=$(echo "$record_id"| head -1)
+                record_data=$(echo "$record_data"| head -1)
+
+                while IFS= read -r line; do
+                    curl -s -X DELETE \
+                        -H "Content-Type: application/json" \
+                        -H "Authorization: Bearer $DIGITALOCEAN_TOKEN" \
+                        "$dns_list/$line" &> /dev/null
+                done <<< "$record_id_to_delete"
+            fi
+
             # re-enable glob expansion
             set +f
-            
+
             data="{\"type\": \"A\", \"name\": \"$sub\", \"data\": \"$ip\"}"
             url="$dns_list/$record_id"