/usr/share/perl/5.22.1/Net/hostent.pm is in perl-modules-5.22 5.22.1-9ubuntu0.6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 | package Net::hostent;
use strict;
use 5.006_001;
our $VERSION = '1.01';
our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS);
BEGIN {
use Exporter ();
@EXPORT = qw(gethostbyname gethostbyaddr gethost);
@EXPORT_OK = qw(
$h_name @h_aliases
$h_addrtype $h_length
@h_addr_list $h_addr
);
%EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] );
}
use vars @EXPORT_OK;
# Class::Struct forbids use of @ISA
sub import { goto &Exporter::import }
use Class::Struct qw(struct);
struct 'Net::hostent' => [
name => '$',
aliases => '@',
addrtype => '$',
'length' => '$',
addr_list => '@',
];
sub addr { shift->addr_list->[0] }
sub populate (@) {
return unless @_;
my $hob = new();
$h_name = $hob->[0] = $_[0];
@h_aliases = @{ $hob->[1] } = split ' ', $_[1];
$h_addrtype = $hob->[2] = $_[2];
$h_length = $hob->[3] = $_[3];
$h_addr = $_[4];
@h_addr_list = @{ $hob->[4] } = @_[ (4 .. $#_) ];
return $hob;
}
sub gethostbyname ($) { populate(CORE::gethostbyname(shift)) }
sub gethostbyaddr ($;$) {
my ($addr, $addrtype);
$addr = shift;
require Socket unless @_;
$addrtype = @_ ? shift : Socket::AF_INET();
populate(CORE::gethostbyaddr($addr, $addrtype))
}
sub gethost($) {
if ($_[0] =~ /^\d+(?:\.\d+(?:\.\d+(?:\.\d+)?)?)?$/) {
require Socket;
&gethostbyaddr(Socket::inet_aton(shift));
} else {
&gethostbyname;
}
}
1;
__END__
=head1 NAME
Net::hostent - by-name interface to Perl's built-in gethost*() functions
=head1 SYNOPSIS
use Net::hostent;
=head1 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 F<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 C<h_>. Thus, C<$host_obj-E<gt>name()> corresponds to
$h_name if you import the fields. Array references are available as
regular array variables, so for example C<@{ $host_obj-E<gt>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 C<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 C<CORE::> pseudo-package.
=head1 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;
}
}
}
=head1 NOTE
While this class is currently implemented using the Class::Struct
module to build a struct-like class, you shouldn't rely upon this.
=head1 AUTHOR
Tom Christiansen
|