The ping_host_add method tries to resolve the host argument, open a
socket and associate everything with the liboping object obj.
The obj argument is a pointer to an liboping object, as returned by
The host parameter is a \0 terminated string which is interpreted as a
hostname or an IP address. Depending on the address family setting, set with
ping_setopt(3), the hostname is resolved to an IPv4 or IPv6 address.
The ping_host_remove method looks for host within obj and remove it if
found. It will close the socket and deallocate the memory, too.
The names passed to ping_host_add and ping_host_remove must match. This
name can be queried using ping_iterator_get_info(3).