Displaying a record pair for a hostname or IP address is likely a common
operation, and using the `show` name makes it clear what the primary
function of the command is. Since record pairs are very simple, the
easiest way to allow both hostname and ip address arguments is to use
grep, which also provides general search-like functionality. In order to
avoid doubling this functionality, use the `show` command in the `list`
command for search.
