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86530b38 AT |
1 | package Net::hostent; |
2 | use strict; | |
3 | ||
4 | use 5.006_001; | |
5 | our $VERSION = '1.00'; | |
6 | our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS); | |
7 | BEGIN { | |
8 | use Exporter (); | |
9 | @EXPORT = qw(gethostbyname gethostbyaddr gethost); | |
10 | @EXPORT_OK = qw( | |
11 | $h_name @h_aliases | |
12 | $h_addrtype $h_length | |
13 | @h_addr_list $h_addr | |
14 | ); | |
15 | %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); | |
16 | } | |
17 | use vars @EXPORT_OK; | |
18 | ||
19 | # Class::Struct forbids use of @ISA | |
20 | sub import { goto &Exporter::import } | |
21 | ||
22 | use Class::Struct qw(struct); | |
23 | struct 'Net::hostent' => [ | |
24 | name => '$', | |
25 | aliases => '@', | |
26 | addrtype => '$', | |
27 | 'length' => '$', | |
28 | addr_list => '@', | |
29 | ]; | |
30 | ||
31 | sub addr { shift->addr_list->[0] } | |
32 | ||
33 | sub populate (@) { | |
34 | return unless @_; | |
35 | my $hob = new(); | |
36 | $h_name = $hob->[0] = $_[0]; | |
37 | @h_aliases = @{ $hob->[1] } = split ' ', $_[1]; | |
38 | $h_addrtype = $hob->[2] = $_[2]; | |
39 | $h_length = $hob->[3] = $_[3]; | |
40 | $h_addr = $_[4]; | |
41 | @h_addr_list = @{ $hob->[4] } = @_[ (4 .. $#_) ]; | |
42 | return $hob; | |
43 | } | |
44 | ||
45 | sub gethostbyname ($) { populate(CORE::gethostbyname(shift)) } | |
46 | ||
47 | sub gethostbyaddr ($;$) { | |
48 | my ($addr, $addrtype); | |
49 | $addr = shift; | |
50 | require Socket unless @_; | |
51 | $addrtype = @_ ? shift : Socket::AF_INET(); | |
52 | populate(CORE::gethostbyaddr($addr, $addrtype)) | |
53 | } | |
54 | ||
55 | sub gethost($) { | |
56 | if ($_[0] =~ /^\d+(?:\.\d+(?:\.\d+(?:\.\d+)?)?)?$/) { | |
57 | require Socket; | |
58 | &gethostbyaddr(Socket::inet_aton(shift)); | |
59 | } else { | |
60 | &gethostbyname; | |
61 | } | |
62 | } | |
63 | ||
64 | 1; | |
65 | __END__ | |
66 | ||
67 | =head1 NAME | |
68 | ||
69 | Net::hostent - by-name interface to Perl's built-in gethost*() functions | |
70 | ||
71 | =head1 SYNOPSIS | |
72 | ||
73 | use Net::hostnet; | |
74 | ||
75 | =head1 DESCRIPTION | |
76 | ||
77 | This module's default exports override the core gethostbyname() and | |
78 | gethostbyaddr() functions, replacing them with versions that return | |
79 | "Net::hostent" objects. This object has methods that return the similarly | |
80 | named structure field name from the C's hostent structure from F<netdb.h>; | |
81 | namely name, aliases, addrtype, length, and addr_list. The aliases and | |
82 | addr_list methods return array reference, the rest scalars. The addr | |
83 | method is equivalent to the zeroth element in the addr_list array | |
84 | reference. | |
85 | ||
86 | You may also import all the structure fields directly into your namespace | |
87 | as regular variables using the :FIELDS import tag. (Note that this still | |
88 | overrides your core functions.) Access these fields as variables named | |
89 | with a preceding C<h_>. Thus, C<$host_obj-E<gt>name()> corresponds to | |
90 | $h_name if you import the fields. Array references are available as | |
91 | regular array variables, so for example C<@{ $host_obj-E<gt>aliases() | |
92 | }> would be simply @h_aliases. | |
93 | ||
94 | The gethost() function is a simple front-end that forwards a numeric | |
95 | argument to gethostbyaddr() by way of Socket::inet_aton, and the rest | |
96 | to gethostbyname(). | |
97 | ||
98 | To access this functionality without the core overrides, | |
99 | pass the C<use> an empty import list, and then access | |
100 | function functions with their full qualified names. | |
101 | On the other hand, the built-ins are still available | |
102 | via the C<CORE::> pseudo-package. | |
103 | ||
104 | =head1 EXAMPLES | |
105 | ||
106 | use Net::hostent; | |
107 | use Socket; | |
108 | ||
109 | @ARGV = ('netscape.com') unless @ARGV; | |
110 | ||
111 | for $host ( @ARGV ) { | |
112 | ||
113 | unless ($h = gethost($host)) { | |
114 | warn "$0: no such host: $host\n"; | |
115 | next; | |
116 | } | |
117 | ||
118 | printf "\n%s is %s%s\n", | |
119 | $host, | |
120 | lc($h->name) eq lc($host) ? "" : "*really* ", | |
121 | $h->name; | |
122 | ||
123 | print "\taliases are ", join(", ", @{$h->aliases}), "\n" | |
124 | if @{$h->aliases}; | |
125 | ||
126 | if ( @{$h->addr_list} > 1 ) { | |
127 | my $i; | |
128 | for $addr ( @{$h->addr_list} ) { | |
129 | printf "\taddr #%d is [%s]\n", $i++, inet_ntoa($addr); | |
130 | } | |
131 | } else { | |
132 | printf "\taddress is [%s]\n", inet_ntoa($h->addr); | |
133 | } | |
134 | ||
135 | if ($h = gethostbyaddr($h->addr)) { | |
136 | if (lc($h->name) ne lc($host)) { | |
137 | printf "\tThat addr reverses to host %s!\n", $h->name; | |
138 | $host = $h->name; | |
139 | redo; | |
140 | } | |
141 | } | |
142 | } | |
143 | ||
144 | =head1 NOTE | |
145 | ||
146 | While this class is currently implemented using the Class::Struct | |
147 | module to build a struct-like class, you shouldn't rely upon this. | |
148 | ||
149 | =head1 AUTHOR | |
150 | ||
151 | Tom Christiansen |