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root |
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package Net::hostent; |
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use strict; |
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use 5.006_001; |
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our $VERSION = '1.01'; |
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our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS); |
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BEGIN { |
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use Exporter (); |
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@EXPORT = qw(gethostbyname gethostbyaddr gethost); |
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@EXPORT_OK = qw( |
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$h_name @h_aliases |
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$h_addrtype $h_length |
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@h_addr_list $h_addr |
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); |
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%EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); |
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} |
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use vars @EXPORT_OK; |
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# Class::Struct forbids use of @ISA |
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sub import { goto &Exporter::import } |
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use Class::Struct qw(struct); |
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struct 'Net::hostent' => [ |
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name => '$', |
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aliases => '@', |
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addrtype => '$', |
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'length' => '$', |
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addr_list => '@', |
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]; |
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sub addr { shift->addr_list->[0] } |
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sub populate (@) { |
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return unless @_; |
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my $hob = new(); |
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$h_name = $hob->[0] = $_[0]; |
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@h_aliases = @{ $hob->[1] } = split ' ', $_[1]; |
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$h_addrtype = $hob->[2] = $_[2]; |
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$h_length = $hob->[3] = $_[3]; |
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$h_addr = $_[4]; |
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@h_addr_list = @{ $hob->[4] } = @_[ (4 .. $#_) ]; |
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return $hob; |
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} |
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sub gethostbyname ($) { populate(CORE::gethostbyname(shift)) } |
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sub gethostbyaddr ($;$) { |
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my ($addr, $addrtype); |
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$addr = shift; |
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require Socket unless @_; |
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$addrtype = @_ ? shift : Socket::AF_INET(); |
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populate(CORE::gethostbyaddr($addr, $addrtype)) |
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} |
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sub gethost($) { |
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if ($_[0] =~ /^\d+(?:\.\d+(?:\.\d+(?:\.\d+)?)?)?$/) { |
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require Socket; |
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&gethostbyaddr(Socket::inet_aton(shift)); |
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} else { |
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&gethostbyname; |
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} |
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} |
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1; |
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__END__ |
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=head1 NAME |
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Net::hostent - by-name interface to Perl's built-in gethost*() functions |
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=head1 SYNOPSIS |
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use Net::hostent; |
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=head1 DESCRIPTION |
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This module's default exports override the core gethostbyname() and |
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gethostbyaddr() functions, replacing them with versions that return |
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"Net::hostent" objects. This object has methods that return the similarly |
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named structure field name from the C's hostent structure from F<netdb.h>; |
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namely name, aliases, addrtype, length, and addr_list. The aliases and |
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addr_list methods return array reference, the rest scalars. The addr |
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method is equivalent to the zeroth element in the addr_list array |
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reference. |
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You may also import all the structure fields directly into your namespace |
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as regular variables using the :FIELDS import tag. (Note that this still |
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overrides your core functions.) Access these fields as variables named |
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with a preceding C<h_>. Thus, C<$host_obj-E<gt>name()> corresponds to |
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$h_name if you import the fields. Array references are available as |
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regular array variables, so for example C<@{ $host_obj-E<gt>aliases() |
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}> would be simply @h_aliases. |
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The gethost() function is a simple front-end that forwards a numeric |
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argument to gethostbyaddr() by way of Socket::inet_aton, and the rest |
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to gethostbyname(). |
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To access this functionality without the core overrides, |
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pass the C<use> an empty import list, and then access |
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function functions with their full qualified names. |
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On the other hand, the built-ins are still available |
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via the C<CORE::> pseudo-package. |
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=head1 EXAMPLES |
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use Net::hostent; |
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use Socket; |
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@ARGV = ('netscape.com') unless @ARGV; |
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for $host ( @ARGV ) { |
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unless ($h = gethost($host)) { |
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warn "$0: no such host: $host\n"; |
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next; |
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} |
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printf "\n%s is %s%s\n", |
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$host, |
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lc($h->name) eq lc($host) ? "" : "*really* ", |
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$h->name; |
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print "\taliases are ", join(", ", @{$h->aliases}), "\n" |
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if @{$h->aliases}; |
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if ( @{$h->addr_list} > 1 ) { |
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my $i; |
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for $addr ( @{$h->addr_list} ) { |
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printf "\taddr #%d is [%s]\n", $i++, inet_ntoa($addr); |
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} |
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} else { |
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printf "\taddress is [%s]\n", inet_ntoa($h->addr); |
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} |
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if ($h = gethostbyaddr($h->addr)) { |
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if (lc($h->name) ne lc($host)) { |
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printf "\tThat addr reverses to host %s!\n", $h->name; |
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$host = $h->name; |
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redo; |
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} |
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} |
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} |
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=head1 NOTE |
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While this class is currently implemented using the Class::Struct |
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module to build a struct-like class, you shouldn't rely upon this. |
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=head1 AUTHOR |
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Tom Christiansen |
