The nslookup function is similar to nsl but works on all platforms
and can resolve ipv6 addresses if supported by the OS. Default behavior raises an
error if lookup fails. The has_internet function tests the internet
connection by resolving a random address.
Usage
nslookup(host, error = TRUE)
has_internet()
Arguments
host
a string with a hostname
error
raise an error for failed DNS lookup. Otherwise returns NULL.