Whois can be queried from the command line using tools available on many operating systems. This is useful for fast checks, technical diagnostics and repeated lookups.
A typical command is:
whois example.comThe result depends on the extension and Whois server. Sometimes the first response points to the authoritative registrar Whois server, so a second query may be needed to obtain more details.
Command line Whois is practical for technicians, but for many users a web-based Whois or RDAP lookup is easier to read and often includes clearer formatting.