[anh79]

whois may not work if you don't have correct configuration (e.g, whois server for some special domains .info, .social, ...)

[teddyh]

Use a proper whois command which has all this configured. Note: may be difficult to achieve on macOS.

[anh79]

It's even hard on Linux machine. How do you know all whois servers for different top level domains? for .info, for .social, for .in, bla bla. In 2016 it's so painful to set up correct whois monitoring at my company . (May be it's a lot better now.)

[teddyh]

apt install whois