Tests if hostname is the string form of an IPv4 or IPv6 address. (Eg, "192.168.0.1".)
Since 2.66, IPv6 addresses with a zone-id are accepted (RFC6874).
a hostname (or IP address in string form)
true if hostname is an IP address
Tests if hostname is the string form of an IPv4 or IPv6 address. (Eg, "192.168.0.1".)
Since 2.66, IPv6 addresses with a zone-id are accepted (RFC6874).