How to use nslookup in bash to verify is DNS is configured properly?

bash nslookup
sorin picture sorin · Dec 9, 2016 · Viewed 20.9k times · Source

Mainly I want to detect if DNS is configured properly on a machine by using nslookup. Sadly it seems that nslookup still returns success error codes when it fails to lookup an entry. Also the fact that different queries could return multiple results makes it harder to test it.

So I want to write a bash snippet that returns success if the dns entry resolved successfully. I don't care if I get multiple results.

Example nslookup -type=srv _ldap._tcp.DOMAIN.COM

Answer

Isaac picture Isaac · Dec 9, 2016

The correct solution would be to use dig and test if there is any text with the short option:

[ "$(dig +short -t srv _ldap._tcp.example.com.)" ] && echo "got answer"

Related questions

How to concatenate string variables in Bash

In PHP, strings are concatenated together as follows: $foo = "Hello"; $foo .= " World"; Here, $foo becomes "Hello World". How is this accomplished in Bash?

Read More
How can I check if a directory exists in a Bash shell script?

What command can be used to check if a directory exists or not, within a Bash shell script?

Read More
How do I tell if a regular file does not exist in Bash?

I've used the following script to see if a file exists: #!/bin/bash FILE=$1 if [ -f $FILE ]; then echo "File $FILE exists." else echo "File $FILE does not exist." fi What's the correct syntax to use if I only want …

Read More