Initial Commit

database/perl/lib/Net/hostent.pm

@@ -0,0 +1,156 @@
+package Net::hostent;
+use strict;
+
+use 5.006_001;
+our $VERSION = '1.02';
+our (@EXPORT, @EXPORT_OK, %EXPORT_TAGS);
+our (
+      $h_name, @h_aliases,
+      $h_addrtype, $h_length,
+      @h_addr_list, $h_addr
+);
+ 
+BEGIN { 
+    use Exporter   ();
+    @EXPORT      = qw(gethostbyname gethostbyaddr gethost);
+    @EXPORT_OK   = qw(
+			$h_name	    	@h_aliases
+			$h_addrtype 	$h_length
+			@h_addr_list 	$h_addr
+		   );
+    %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] );
+}
+
+# Class::Struct forbids use of @ISA
+sub import { goto &Exporter::import }
+
+use Class::Struct qw(struct);
+struct 'Net::hostent' => [
+   name		=> '$',
+   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