xref: /onnv-gate/usr/src/cmd/perl/5.8.4/distrib/lib/Net/hostent.pm (revision 0:68f95e015346)
1*0Sstevel@tonic-gatepackage Net::hostent;
2*0Sstevel@tonic-gateuse strict;
3*0Sstevel@tonic-gate
4*0Sstevel@tonic-gateuse 5.006_001;
5*0Sstevel@tonic-gateour $VERSION = '1.01';
6*0Sstevel@tonic-gateour(@EXPORT, @EXPORT_OK, %EXPORT_TAGS);
7*0Sstevel@tonic-gateBEGIN {
8*0Sstevel@tonic-gate    use Exporter   ();
9*0Sstevel@tonic-gate    @EXPORT      = qw(gethostbyname gethostbyaddr gethost);
10*0Sstevel@tonic-gate    @EXPORT_OK   = qw(
11*0Sstevel@tonic-gate			$h_name	    	@h_aliases
12*0Sstevel@tonic-gate			$h_addrtype 	$h_length
13*0Sstevel@tonic-gate			@h_addr_list 	$h_addr
14*0Sstevel@tonic-gate		   );
15*0Sstevel@tonic-gate    %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] );
16*0Sstevel@tonic-gate}
17*0Sstevel@tonic-gateuse vars      @EXPORT_OK;
18*0Sstevel@tonic-gate
19*0Sstevel@tonic-gate# Class::Struct forbids use of @ISA
20*0Sstevel@tonic-gatesub import { goto &Exporter::import }
21*0Sstevel@tonic-gate
22*0Sstevel@tonic-gateuse Class::Struct qw(struct);
23*0Sstevel@tonic-gatestruct 'Net::hostent' => [
24*0Sstevel@tonic-gate   name		=> '$',
25*0Sstevel@tonic-gate   aliases	=> '@',
26*0Sstevel@tonic-gate   addrtype	=> '$',
27*0Sstevel@tonic-gate   'length'	=> '$',
28*0Sstevel@tonic-gate   addr_list	=> '@',
29*0Sstevel@tonic-gate];
30*0Sstevel@tonic-gate
31*0Sstevel@tonic-gatesub addr { shift->addr_list->[0] }
32*0Sstevel@tonic-gate
33*0Sstevel@tonic-gatesub populate (@) {
34*0Sstevel@tonic-gate    return unless @_;
35*0Sstevel@tonic-gate    my $hob = new();
36*0Sstevel@tonic-gate    $h_name 	 =    $hob->[0]     	     = $_[0];
37*0Sstevel@tonic-gate    @h_aliases	 = @{ $hob->[1] } = split ' ', $_[1];
38*0Sstevel@tonic-gate    $h_addrtype  =    $hob->[2] 	     = $_[2];
39*0Sstevel@tonic-gate    $h_length	 =    $hob->[3] 	     = $_[3];
40*0Sstevel@tonic-gate    $h_addr 	 =                             $_[4];
41*0Sstevel@tonic-gate    @h_addr_list = @{ $hob->[4] } =          @_[ (4 .. $#_) ];
42*0Sstevel@tonic-gate    return $hob;
43*0Sstevel@tonic-gate}
44*0Sstevel@tonic-gate
45*0Sstevel@tonic-gatesub gethostbyname ($)  { populate(CORE::gethostbyname(shift)) }
46*0Sstevel@tonic-gate
47*0Sstevel@tonic-gatesub gethostbyaddr ($;$) {
48*0Sstevel@tonic-gate    my ($addr, $addrtype);
49*0Sstevel@tonic-gate    $addr = shift;
50*0Sstevel@tonic-gate    require Socket unless @_;
51*0Sstevel@tonic-gate    $addrtype = @_ ? shift : Socket::AF_INET();
52*0Sstevel@tonic-gate    populate(CORE::gethostbyaddr($addr, $addrtype))
53*0Sstevel@tonic-gate}
54*0Sstevel@tonic-gate
55*0Sstevel@tonic-gatesub gethost($) {
56*0Sstevel@tonic-gate    if ($_[0] =~ /^\d+(?:\.\d+(?:\.\d+(?:\.\d+)?)?)?$/) {
57*0Sstevel@tonic-gate	require Socket;
58*0Sstevel@tonic-gate	&gethostbyaddr(Socket::inet_aton(shift));
59*0Sstevel@tonic-gate    } else {
60*0Sstevel@tonic-gate	&gethostbyname;
61*0Sstevel@tonic-gate    }
62*0Sstevel@tonic-gate}
63*0Sstevel@tonic-gate
64*0Sstevel@tonic-gate1;
65*0Sstevel@tonic-gate__END__
66*0Sstevel@tonic-gate
67*0Sstevel@tonic-gate=head1 NAME
68*0Sstevel@tonic-gate
69*0Sstevel@tonic-gateNet::hostent - by-name interface to Perl's built-in gethost*() functions
70*0Sstevel@tonic-gate
71*0Sstevel@tonic-gate=head1 SYNOPSIS
72*0Sstevel@tonic-gate
73*0Sstevel@tonic-gate use Net::hostent;
74*0Sstevel@tonic-gate
75*0Sstevel@tonic-gate=head1 DESCRIPTION
76*0Sstevel@tonic-gate
77*0Sstevel@tonic-gateThis module's default exports override the core gethostbyname() and
78*0Sstevel@tonic-gategethostbyaddr() functions, replacing them with versions that return
79*0Sstevel@tonic-gate"Net::hostent" objects.  This object has methods that return the similarly
80*0Sstevel@tonic-gatenamed structure field name from the C's hostent structure from F<netdb.h>;
81*0Sstevel@tonic-gatenamely name, aliases, addrtype, length, and addr_list.  The aliases and
82*0Sstevel@tonic-gateaddr_list methods return array reference, the rest scalars.  The addr
83*0Sstevel@tonic-gatemethod is equivalent to the zeroth element in the addr_list array
84*0Sstevel@tonic-gatereference.
85*0Sstevel@tonic-gate
86*0Sstevel@tonic-gateYou may also import all the structure fields directly into your namespace
87*0Sstevel@tonic-gateas regular variables using the :FIELDS import tag.  (Note that this still
88*0Sstevel@tonic-gateoverrides your core functions.)  Access these fields as variables named
89*0Sstevel@tonic-gatewith a preceding C<h_>.  Thus, C<$host_obj-E<gt>name()> corresponds to
90*0Sstevel@tonic-gate$h_name if you import the fields.  Array references are available as
91*0Sstevel@tonic-gateregular array variables, so for example C<@{ $host_obj-E<gt>aliases()
92*0Sstevel@tonic-gate}> would be simply @h_aliases.
93*0Sstevel@tonic-gate
94*0Sstevel@tonic-gateThe gethost() function is a simple front-end that forwards a numeric
95*0Sstevel@tonic-gateargument to gethostbyaddr() by way of Socket::inet_aton, and the rest
96*0Sstevel@tonic-gateto gethostbyname().
97*0Sstevel@tonic-gate
98*0Sstevel@tonic-gateTo access this functionality without the core overrides,
99*0Sstevel@tonic-gatepass the C<use> an empty import list, and then access
100*0Sstevel@tonic-gatefunction functions with their full qualified names.
101*0Sstevel@tonic-gateOn the other hand, the built-ins are still available
102*0Sstevel@tonic-gatevia the C<CORE::> pseudo-package.
103*0Sstevel@tonic-gate
104*0Sstevel@tonic-gate=head1 EXAMPLES
105*0Sstevel@tonic-gate
106*0Sstevel@tonic-gate use Net::hostent;
107*0Sstevel@tonic-gate use Socket;
108*0Sstevel@tonic-gate
109*0Sstevel@tonic-gate @ARGV = ('netscape.com') unless @ARGV;
110*0Sstevel@tonic-gate
111*0Sstevel@tonic-gate for $host ( @ARGV ) {
112*0Sstevel@tonic-gate
113*0Sstevel@tonic-gate    unless ($h = gethost($host)) {
114*0Sstevel@tonic-gate	warn "$0: no such host: $host\n";
115*0Sstevel@tonic-gate	next;
116*0Sstevel@tonic-gate    }
117*0Sstevel@tonic-gate
118*0Sstevel@tonic-gate    printf "\n%s is %s%s\n",
119*0Sstevel@tonic-gate	    $host,
120*0Sstevel@tonic-gate	    lc($h->name) eq lc($host) ? "" : "*really* ",
121*0Sstevel@tonic-gate	    $h->name;
122*0Sstevel@tonic-gate
123*0Sstevel@tonic-gate    print "\taliases are ", join(", ", @{$h->aliases}), "\n"
124*0Sstevel@tonic-gate		if @{$h->aliases};
125*0Sstevel@tonic-gate
126*0Sstevel@tonic-gate    if ( @{$h->addr_list} > 1 ) {
127*0Sstevel@tonic-gate	my $i;
128*0Sstevel@tonic-gate	for $addr ( @{$h->addr_list} ) {
129*0Sstevel@tonic-gate	    printf "\taddr #%d is [%s]\n", $i++, inet_ntoa($addr);
130*0Sstevel@tonic-gate	}
131*0Sstevel@tonic-gate    } else {
132*0Sstevel@tonic-gate	printf "\taddress is [%s]\n", inet_ntoa($h->addr);
133*0Sstevel@tonic-gate    }
134*0Sstevel@tonic-gate
135*0Sstevel@tonic-gate    if ($h = gethostbyaddr($h->addr)) {
136*0Sstevel@tonic-gate	if (lc($h->name) ne lc($host)) {
137*0Sstevel@tonic-gate	    printf "\tThat addr reverses to host %s!\n", $h->name;
138*0Sstevel@tonic-gate	    $host = $h->name;
139*0Sstevel@tonic-gate	    redo;
140*0Sstevel@tonic-gate	}
141*0Sstevel@tonic-gate    }
142*0Sstevel@tonic-gate }
143*0Sstevel@tonic-gate
144*0Sstevel@tonic-gate=head1 NOTE
145*0Sstevel@tonic-gate
146*0Sstevel@tonic-gateWhile this class is currently implemented using the Class::Struct
147*0Sstevel@tonic-gatemodule to build a struct-like class, you shouldn't rely upon this.
148*0Sstevel@tonic-gate
149*0Sstevel@tonic-gate=head1 AUTHOR
150*0Sstevel@tonic-gate
151*0Sstevel@tonic-gateTom Christiansen
152