Tool for name server look up on IP address list
```shell
kali@kali:bt-nslookup> ./bt-nslookup -h
Usage: /usr/local/bin/bt-nslookup -f <target_file> -o <output_file> [-t <max_threads>]
Options:
-f <target_file> File containing target list
-o <output_file> Output file to save results
-t <max_threads> Maximum number of threads (default: 40, max: 100)
-h Display this help message
You can use grep to get your specific target
cat output.txt | grep example.com
cat output.txt | grep -E "example.com|nmap.org"