use Net::hostnet;
gethostbyname
and gethostbyaddr functions, replacing them with versions that
return ``Net::hostent'' objects. This object has methods that return the
similarly named structure field name from the C's hostent structure from netdb.h; namely name, aliases, addrtype, length, and addresses. The aliases and
addresses methods return array reference, the rest scalars. The addr method
is equivalent to the zeroth element in the addresses array reference.
You may also import all the structure fields directly into your namespace as regular variables using the
:FIELDS import tag. (Note that this still overrides your core functions.) Access these fields as variables named with a preceding
h_. Thus, $host_obj->name corresponds to $h_name if you import the fields. Array
references are available as regular array variables, so for example @{ $host_obj->aliases
} would be simply @h_aliases.
The gethost funtion is a simple front-end that forwards a
numeric argument to gethostbyaddr by way of Socket::inet_aton,
and the rest to gethostbyname.
To access this functionality without the core overrides, pass the use an empty import list, and then access function functions with their full
qualified names. On the other hand, the built-ins are still available via
the CORE:: pseudo-package.
use Net::hostent; use Socket;
@ARGV = ('netscape.com') unless @ARGV;
for $host ( @ARGV ) {
unless ($h = gethost($host)) {
warn "$0: no such host: $host\n";
next;
}
printf "\n%s is %s%s\n", $host, lc($h->name) eq lc($host) ? "" : "*really* ", $h->name;
print "\taliases are ", join(", ", @{$h->aliases}), "\n"
if @{$h->aliases};
if ( @{$h->addr_list} > 1 ) {
my $i;
for $addr ( @{$h->addr_list} ) {
printf "\taddr #%d is [%s]\n", $i++, inet_ntoa($addr);
}
} else {
printf "\taddress is [%s]\n", inet_ntoa($h->addr);
}
if ($h = gethostbyaddr($h->addr)) {
if (lc($h->name) ne lc($host)) {
printf "\tThat addr reverses to host %s!\n", $h->name;
$host = $h->name;
redo;
}
}
}