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Diffstat (limited to 'lib/Net/hostent.pm')
| -rw-r--r-- | lib/Net/hostent.pm | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/lib/Net/hostent.pm b/lib/Net/hostent.pm new file mode 100644 index 0000000000..dfca789817 --- /dev/null +++ b/lib/Net/hostent.pm @@ -0,0 +1,149 @@ +package Net::hostent; +use strict; + +BEGIN { + use Exporter (); + use vars qw(@EXPORT @EXPORT_OK %EXPORT_TAGS); + @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::hostnet; + +=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 addresses. The aliases and +addresses methods return array reference, the rest scalars. The addr +method is equivalent to the zeroth element in the addresses 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() funtion 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 |