If you are getting an error saying "dig command not found" on CentOS 7, it means that the dig command is not installed on your system.
To install the dig command on CentOS 7, you will need to use the yum package manager.
First, update the package manager's package repository by running the following command:
sudo yum update
Then, install the dig command by running the following command:
sudo yum install bind-utils
This will install the dig command as well as other utilities from the BIND package, such as nslookup and host.
Once the installation is complete, you should be able to use the dig command to perform DNS lookups and other tasks.
For more information on using the dig command and the package manager on CentOS 7, you can consult the documentation or seek guidance from the CentOS community.