NAME¶
Net::hostent - by-name interface to Perl's built-in gethost*() functions
SYNOPSIS¶
use Net::hostent;
DESCRIPTION¶
This module's default exports override the core
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 addr_list. The
aliases and addr_list methods return array reference, the rest scalars. The
addr method is equivalent to the zeroth element in the addr_list 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() function 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.
EXAMPLES¶
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;
}
}
}
NOTE¶
While this class is currently implemented using the Class::Struct module to
build a struct-like class, you shouldn't rely upon this.
AUTHOR¶
Tom Christiansen