let’s assume our desired fqdn is foobar.example.com. Now
$ hostname
should display “foobar”
$ hostname -d
should display “example.com”
$ dnsdomainname
should display “example.com”
$ cat /etc/hosts
should have following 2 lines
127.0.0.1 localhost
127.0.1.1 foobar.example.com foobar
