use Catalyst::Exception ();
use Digest ();
use overload ();
+use Object::Signature ();
+use Carp;
-our $VERSION = "0.01";
+our $VERSION = '0.19_01';
+my @session_data_accessors; # used in delete_session
BEGIN {
- __PACKAGE__->mk_accessors(qw/sessionid session_delete_reason/);
+ __PACKAGE__->mk_accessors(
+ "_session_delete_reason",
+ @session_data_accessors = qw/
+ _sessionid
+ _session
+ _session_expires
+ _extended_session_expires
+ _session_data_sig
+ _flash
+ _flash_keep_keys
+ _flash_key_hashes
+ _tried_loading_session_id
+ _tried_loading_session_data
+ _tried_loading_session_expires
+ _tried_loading_flash_data
+ /
+ );
}
sub setup {
%$cfg = (
expires => 7200,
- verify_address => 1,
+ verify_address => 0,
%$cfg,
);
$c->NEXT::setup_session();
}
-sub finalize {
+sub prepare_action {
+ my $c = shift;
+
+ if ( $c->config->{session}{flash_to_stash}
+ and $c->sessionid
+ and my $flash_data = $c->flash )
+ {
+ @{ $c->stash }{ keys %$flash_data } = values %$flash_data;
+ }
+
+ $c->NEXT::prepare_action(@_);
+}
+
+sub finalize_headers {
+ my $c = shift;
+
+ # fix cookie before we send headers
+ $c->_save_session_expires;
+
+ return $c->NEXT::finalize_headers(@_);
+}
+
+sub finalize_body {
+ my $c = shift;
+
+ # We have to finalize our session *before* $c->engine->finalize_xxx is called,
+ # because we do not want to send the HTTP response before the session is stored/committed to
+ # the session database (or whatever Session::Store you use).
+ $c->finalize_session;
+
+ return $c->NEXT::finalize_body(@_);
+}
+
+sub finalize_session {
+ my $c = shift;
+
+ $c->NEXT::finalize_session;
+
+ $c->_save_session_id;
+ $c->_save_session;
+ $c->_save_flash;
+
+ $c->_clear_session_instance_data;
+}
+
+sub _save_session_id {
+ my $c = shift;
+
+ # we already called set when allocating
+ # no need to tell the state plugins anything new
+}
+
+sub _save_session_expires {
+ my $c = shift;
+
+ if ( defined($c->_session_expires) ) {
+ my $expires = $c->session_expires; # force extension
+
+ my $sid = $c->sessionid;
+ $c->store_session_data( "expires:$sid" => $expires );
+ }
+}
+
+sub _save_session {
my $c = shift;
- if ( $c->{session} ) {
+ if ( my $session_data = $c->_session ) {
- # all sessions are extended at the end of the request
- my $now = time;
- @{ $c->{session} }{qw/__updated __expires/} =
- ( $now, $c->config->{session}{expires} + $now );
- $c->store_session_data( $c->sessionid, $c->{session} );
+ no warnings 'uninitialized';
+ if ( Object::Signature::signature($session_data) ne
+ $c->_session_data_sig )
+ {
+ $session_data->{__updated} = time();
+ my $sid = $c->sessionid;
+ $c->store_session_data( "session:$sid" => $session_data );
+ }
}
+}
+
+sub _save_flash {
+ my $c = shift;
+
+ if ( my $flash_data = $c->_flash ) {
- $c->NEXT::finalize(@_);
+ my $hashes = $c->_flash_key_hashes || {};
+ my $keep = $c->_flash_keep_keys || {};
+ foreach my $key ( keys %$hashes ) {
+ if ( !exists $keep->{$key} and Object::Signature::signature( \$flash_data->{$key} ) eq $hashes->{$key} ) {
+ delete $flash_data->{$key};
+ }
+ }
+
+ my $sid = $c->sessionid;
+
+ my $session_data = $c->_session;
+ if (%$flash_data) {
+ $session_data->{__flash} = $flash_data;
+ }
+ else {
+ delete $session_data->{__flash};
+ }
+ $c->_session($session_data);
+ $c->_save_session;
+ }
}
-sub prepare_action {
+sub _load_session_expires {
my $c = shift;
+ return $c->_session_expires if $c->_tried_loading_session_expires;
+ $c->_tried_loading_session_expires(1);
+
+ if ( my $sid = $c->sessionid ) {
+ my $expires = $c->get_session_data("expires:$sid") || 0;
+
+ if ( $expires >= time() ) {
+ $c->_session_expires( $expires );
+ return $expires;
+ } else {
+ $c->delete_session( "session expired" );
+ return 0;
+ }
+ }
- my $ret = $c->NEXT::prepare_action;
+ return;
+}
- my $sid = $c->sessionid || return;
+sub _load_session {
+ my $c = shift;
+ return $c->_session if $c->_tried_loading_session_data;
+ $c->_tried_loading_session_data(1);
+
+ if ( my $sid = $c->sessionid ) {
+ if ( $c->_load_session_expires ) { # > 0
+
+ my $session_data = $c->get_session_data("session:$sid") || return;
+ $c->_session($session_data);
+
+ no warnings 'uninitialized'; # ne __address
+ if ( $c->config->{session}{verify_address}
+ && $session_data->{__address} ne $c->request->address )
+ {
+ $c->log->warn(
+ "Deleting session $sid due to address mismatch ("
+ . $session_data->{__address} . " != "
+ . $c->request->address . ")"
+ );
+ $c->delete_session("address mismatch");
+ return;
+ }
+
+ $c->log->debug(qq/Restored session "$sid"/) if $c->debug;
+ $c->_session_data_sig( Object::Signature::signature($session_data) ) if $session_data;
+ $c->_expire_session_keys;
+
+ return $session_data;
+ }
+ }
- $c->log->debug(qq/Found session "$sid"/) if $c->debug;
+ return;
+}
- my $s = $c->{session} ||= $c->get_session_data($sid);
- if ( !$s or $s->{__expires} < time ) {
+sub _load_flash {
+ my $c = shift;
+ return $c->_flash if $c->_tried_loading_flash_data;
+ $c->_tried_loading_flash_data(1);
+
+ if ( my $sid = $c->sessionid ) {
+
+ my $session_data = $c->session;
+ $c->_flash($session_data->{__flash});
- # session expired
- $c->log->debug("Deleting session $sid (expired)") if $c->debug;
- $c->delete_session("session expired");
- return $ret;
+ if ( my $flash_data = $c->_flash )
+ {
+ $c->_flash_key_hashes({ map { $_ => Object::Signature::signature( \$flash_data->{$_} ) } keys %$flash_data });
+
+ return $flash_data;
+ }
}
- if ( $c->config->{session}{verify_address}
- && $c->{session}{__address}
- && $c->{session}{__address} ne $c->request->address )
- {
- $c->log->warn(
- "Deleting session $sid due to address mismatch ("
- . $c->{session}{__address} . " != "
- . $c->request->address . ")",
- );
- $c->delete_session("address mismatch");
- return $ret;
+ return;
+}
+
+sub _expire_session_keys {
+ my ( $c, $data ) = @_;
+
+ my $now = time;
+
+ my $expire_times = ( $data || $c->_session || {} )->{__expire_keys} || {};
+ foreach my $key ( grep { $expire_times->{$_} < $now } keys %$expire_times ) {
+ delete $c->_session->{$key};
+ delete $expire_times->{$key};
}
}
+sub _clear_session_instance_data {
+ my $c = shift;
+ $c->$_(undef) for @session_data_accessors;
+ $c->NEXT::_clear_session_instance_data; # allow other plugins to hook in on this
+}
+
sub delete_session {
my ( $c, $msg ) = @_;
+ $c->log->debug("Deleting session" . ( defined($msg) ? "($msg)" : '(no reason given)') ) if $c->debug;
+
# delete the session data
- my $sid = $c->sessionid;
- $c->delete_session_data($sid);
+ if ( my $sid = $c->sessionid ) {
+ $c->delete_session_data("${_}:${sid}") for qw/session expires flash/;
+ $c->delete_session_id($sid);
+ }
# reset the values in the context object
- $c->{session} = undef;
- $c->sessionid(undef);
- $c->session_delete_reason($msg);
+ # see the BEGIN block
+ $c->_clear_session_instance_data;
+
+ $c->_session_delete_reason($msg);
+}
+
+sub session_delete_reason {
+ my $c = shift;
+
+ $c->session_is_valid; # check that it was loaded
+
+ $c->_session_delete_reason(@_);
+}
+
+sub session_expires {
+ my $c = shift;
+
+ if ( defined( my $expires = $c->_extended_session_expires ) ) {
+ return $expires;
+ } elsif ( defined( $expires = $c->_load_session_expires ) ) {
+ return $c->extend_session_expires( $expires );
+ } else {
+ return 0;
+ }
+}
+
+sub extend_session_expires {
+ my ( $c, $expires ) = @_;
+ $c->_extended_session_expires( my $updated = $c->calculate_extended_session_expires( $expires ) );
+ $c->extend_session_id( $c->sessionid, $updated );
+ return $updated;
+}
+
+sub calculate_initial_session_expires {
+ my $c = shift;
+ return ( time() + $c->config->{session}{expires} );
+}
+
+sub calculate_extended_session_expires {
+ my ( $c, $prev ) = @_;
+ $c->calculate_initial_session_expires;
+}
+
+sub reset_session_expires {
+ my ( $c, $sid ) = @_;
+
+ my $exp = $c->calculate_initial_session_expires;
+ $c->_session_expires( $exp );
+ $c->_extended_session_expires( $exp );
+ $exp;
+}
+
+sub sessionid {
+ my $c = shift;
+
+ return $c->_sessionid || $c->_load_sessionid;
+}
+
+sub _load_sessionid {
+ my $c = shift;
+ return if $c->_tried_loading_session_id;
+ $c->_tried_loading_session_id(1);
+
+ if ( defined( my $sid = $c->get_session_id ) ) {
+ if ( $c->validate_session_id($sid) ) {
+ # temporarily set the inner key, so that validation will work
+ $c->_sessionid($sid);
+ return $sid;
+ } else {
+ my $err = "Tried to set invalid session ID '$sid'";
+ $c->log->error($err);
+ Catalyst::Exception->throw($err);
+ }
+ }
+
+ return;
+}
+
+sub session_is_valid {
+ my $c = shift;
+
+ # force a check for expiry, but also __address, etc
+ if ( $c->_load_session ) {
+ return 1;
+ } else {
+ return;
+ }
+}
+
+sub validate_session_id {
+ my ( $c, $sid ) = @_;
+
+ $sid and $sid =~ /^[a-f\d]+$/i;
}
sub session {
my $c = shift;
- return $c->{session} if $c->{session};
+ $c->_session || $c->_load_session || do {
+ $c->create_session_id_if_needed;
+ $c->initialize_session_data;
+ };
+}
- my $sid = $c->generate_session_id;
- $c->sessionid($sid);
+sub keep_flash {
+ my ( $c, @keys ) = @_;
+ my $href = $c->_flash_keep_keys || $c->_flash_keep_keys({});
+ (@{$href}{@keys}) = ((undef) x @keys);
+}
- $c->log->debug(qq/Created session "$sid"/) if $c->debug;
+sub _flash_data {
+ my $c = shift;
+ $c->_flash || $c->_load_flash || do {
+ $c->create_session_id_if_needed;
+ $c->_flash( {} );
+ };
+}
+
+sub _set_flash {
+ my $c = shift;
+ if (@_) {
+ my $items = @_ > 1 ? {@_} : $_[0];
+ croak('flash takes a hash or hashref') unless ref $items;
+ @{ $c->_flash }{ keys %$items } = values %$items;
+ }
+}
+
+sub flash {
+ my $c = shift;
+ $c->_flash_data;
+ $c->_set_flash(@_);
+ return $c->_flash;
+}
+
+sub clear_flash {
+ my $c = shift;
+
+ #$c->delete_session_data("flash:" . $c->sessionid); # should this be in here? or delayed till finalization?
+ $c->_flash_key_hashes({});
+ $c->_flash_keep_keys({});
+ $c->_flash({});
+}
+
+sub session_expire_key {
+ my ( $c, %keys ) = @_;
- return $c->initialize_session_data;
+ my $now = time;
+ @{ $c->session->{__expire_keys} }{ keys %keys } =
+ map { $now + $_ } values %keys;
}
sub initialize_session_data {
my $now = time;
- return $c->{session} = {
- __created => $now,
- __updated => $now,
- __expires => $now + $c->config->{session}{expires},
+ return $c->_session(
+ {
+ __created => $now,
+ __updated => $now,
- (
- $c->config->{session}{verify_address}
- ? ( __address => $c->request->address )
- : ()
- ),
- };
+ (
+ $c->config->{session}{verify_address}
+ ? ( __address => $c->request->address )
+ : ()
+ ),
+ }
+ );
}
sub generate_session_id {
return $digest->hexdigest;
}
+sub create_session_id_if_needed {
+ my $c = shift;
+ $c->create_session_id unless $c->sessionid;
+}
+
+sub create_session_id {
+ my $c = shift;
+
+ my $sid = $c->generate_session_id;
+
+ $c->log->debug(qq/Created session "$sid"/) if $c->debug;
+
+ $c->_sessionid($sid);
+ $c->reset_session_expires;
+ $c->set_session_id($sid);
+
+ return $sid;
+}
+
my $counter;
sub session_hash_seed {
sub _find_digest () {
unless ($usable) {
- foreach my $alg (qw/SHA-1 MD5 SHA-256/) {
- eval {
- my $obj = Digest->new($alg);
- $usable = $alg;
- return $obj;
- }
+ foreach my $alg (qw/SHA-1 SHA-256 MD5/) {
+ if ( eval { Digest->new($alg) } ) {
+ $usable = $alg;
+ last;
+ }
}
- $usable
- or Catalyst::Exception->throw(
+ Catalyst::Exception->throw(
"Could not find a suitable Digest module. Please install "
- . "Digest::SHA1, Digest::SHA, or Digest::MD5" );
+ . "Digest::SHA1, Digest::SHA, or Digest::MD5" )
+ unless $usable;
}
return Digest->new($usable);
);
}
+
+sub get_session_id { shift->NEXT::get_session_id(@_) }
+sub set_session_id { shift->NEXT::set_session_id(@_) }
+sub delete_session_id { shift->NEXT::delete_session_id(@_) }
+sub extend_session_id { shift->NEXT::extend_session_id(@_) }
+
__PACKAGE__;
__END__
=head1 NAME
-Catalyst::Plugin::Session - Generic Session plugin - ties together server side
-storage and client side tickets required to maintain session data.
+Catalyst::Plugin::Session - Generic Session plugin - ties together server side storage and client side state required to maintain session data.
=head1 SYNOPSIS
- use Catalyst qw/Session Session::Store::FastMmap Session::State::Cookie/;
+ # To get sessions to "just work", all you need to do is use these plugins:
+
+ use Catalyst qw/
+ Session
+ Session::Store::FastMmap
+ Session::State::Cookie
+ /;
+
+ # you can replace Store::FastMmap with Store::File - both have sensible
+ # default configurations (see their docs for details)
+
+ # more complicated backends are available for other scenarios (DBI storage,
+ # etc)
+
+
+ # after you've loaded the plugins you can save session data
+ # For example, if you are writing a shopping cart, it could be implemented
+ # like this:
sub add_item : Local {
my ( $self, $c ) = @_;
my $item_id = $c->req->param("item");
- # $c->session is stored across requests, so
- # other actions will see these values
+ # $c->session is a hash ref, a bit like $c->stash
+ # the difference is that it' preserved across requests
push @{ $c->session->{items} }, $item_id;
# values in $c->session are restored
$c->stash->{items_to_display} =
- [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ];
+ [ map { MyModel->retrieve($_) } @{ $c->session->{items} } ];
$c->forward("MyView");
}
This plugin links the two pieces together.
+=head1 RECOMENDED BACKENDS
+
+=over 4
+
+=item Session::State::Cookie
+
+The only really sane way to do state is using cookies.
+
+=item Session::Store::File
+
+A portable backend, based on Cache::File.
+
+=item Session::Store::FastMmap
+
+A fast and flexible backend, based on Cache::FastMmap.
+
+=back
+
=head1 METHODS
=over 4
This method will automatically create a new session and session ID if none
exists.
+=item session_expires
+
+=item session_expires $reset
+
+This method returns the time when the current session will expire, or 0 if
+there is no current session. If there is a session and it already expired, it
+will delete the session and return 0 as well.
+
+If the C<$reset> parameter is true, and there is a session ID the expiry time
+will be reset to the current time plus the time to live (see
+L</CONFIGURATION>). This is used when creating a new session.
+
+=item flash
+
+This is like Ruby on Rails' flash data structure. Think of it as a stash that
+lasts for longer than one request, letting you redirect instead of forward.
+
+The flash data will be cleaned up only on requests on which actually use
+$c->flash (thus allowing multiple redirections), and the policy is to delete
+all the keys which haven't changed since the flash data was loaded at the end
+of every request.
+
+ sub moose : Local {
+ my ( $self, $c ) = @_;
+
+ $c->flash->{beans} = 10;
+ $c->response->redirect( $c->uri_for("foo") );
+ }
+
+ sub foo : Local {
+ my ( $self, $c ) = @_;
+
+ my $value = $c->flash->{beans};
+
+ # ...
+
+ $c->response->redirect( $c->uri_for("bar") );
+ }
+
+ sub bar : Local {
+ my ( $self, $c ) = @_;
+
+ if ( exists $c->flash->{beans} ) { # false
+
+ }
+ }
+
+=item clear_flash
+
+Zap all the keys in the flash regardless of their current state.
+
+=item keep_flash @keys
+
+If you want to keep a flash key for the next request too, even if it hasn't
+changed, call C<keep_flash> and pass in the keys as arguments.
+
+=item delete_session REASON
+
+This method is used to invalidate a session. It takes an optional parameter
+which will be saved in C<session_delete_reason> if provided.
+
+NOTE: This method will B<also> delete your flash data.
+
=item session_delete_reason
This accessor contains a string with the reason a session was deleted. Possible
=back
+=item session_expire_key $key, $ttl
+
+Mark a key to expire at a certain time (only useful when shorter than the
+expiry time for the whole session).
+
+For example:
+
+ __PACKAGE__->config->{session}{expires} = 1000000000000; # forever
+
+ # later
+
+ $c->session_expire_key( __user => 3600 );
+
+Will make the session data survive, but the user will still be logged out after
+an hour.
+
+Note that these values are not auto extended.
+
+=back
+
+=head1 INTERNAL METHODS
+
+=over 4
+
=item setup
This method is extended to also make calls to
=item prepare_action
-This methoid is extended, and will restore session data and check it for
-validity if a session id is defined. It assumes that the State plugin will
-populate the C<sessionid> key beforehand.
+This method is extended.
-=item finalize
+Its only effect is if the (off by default) C<flash_to_stash> configuration
+parameter is on - then it will copy the contents of the flash to the stash at
+prepare time.
-This method is extended and will extend the expiry time, as well as persist the
-session data if a session exists.
+=item finalize_headers
-=item delete_session REASON
+This method is extended and will extend the expiry time before sending
+the response.
-This method is used to invalidate a session. It takes an optional parameter
-which will be saved in C<session_delete_reason> if provided.
+=item finalize_body
+
+This method is extended and will call finalize_session before the other
+finalize_body methods run. Here we persist the session data if a session exists.
=item initialize_session_data
This method will initialize the internal structure of the session, and is
called by the C<session> method if appropriate.
+=item create_session_id
+
+Creates a new session ID using C<generate_session_id> if there is no session ID
+yet.
+
+=item validate_session_id SID
+
+Make sure a session ID is of the right format.
+
+This currently ensures that the session ID string is any amount of case
+insensitive hexadecimal characters.
+
=item generate_session_id
This method will return a string that can be used as a session ID. It is
supposed to be a reasonably random string with enough bits to prevent
collision. It basically takes C<session_hash_seed> and hashes it using SHA-1,
-MD5 or SHA-256, depending on the availibility of these modules.
+MD5 or SHA-256, depending on the availability of these modules.
=item session_hash_seed
=over 4
-=item *
-
-A counter
-
-=item *
-
-The current time
-
-=item *
+=item * A counter
-One value from C<rand>.
+=item * The current time
-=item *
+=item * One value from C<rand>.
-The stringified value of a newly allocated hash reference
+=item * The stringified value of a newly allocated hash reference
-=item *
-
-The stringified value of the Catalyst context object
+=item * The stringified value of the Catalyst context object
=back
-In the hopes that those combined values are entropic enough for most uses. If
+in the hopes that those combined values are entropic enough for most uses. If
this is not the case you can replace C<session_hash_seed> with e.g.
sub session_hash_seed {
Also have a look at L<Crypt::Random> and the various openssl bindings - these
modules provide APIs for cryptographically secure random data.
+=item finalize_session
+
+Clean up the session during C<finalize>.
+
+This clears the various accessors after saving to the store.
+
=item dump_these
See L<Catalyst/dump_these> - ammends the session data structure to the list of
dumped objects if session ID is defined.
+
+=item calculate_extended_session_expires
+
+=item calculate_initial_session_expires
+
+=item create_session_id_if_needed
+
+=item delete_session_id
+
+=item extend_session_expires
+
+=item extend_session_id
+
+=item get_session_id
+
+=item reset_session_expires
+
+=item session_is_valid
+
+=item set_session_id
+
=back
+=head1 USING SESSIONS DURING PREPARE
+
+The earliest point in time at which you may use the session data is after
+L<Catalyst::Plugin::Session>'s C<prepare_action> has finished.
+
+State plugins must set $c->session ID before C<prepare_action>, and during
+C<prepare_action> L<Catalyst::Plugin::Session> will actually load the data from
+the store.
+
+ sub prepare_action {
+ my $c = shift;
+
+ # don't touch $c->session yet!
+
+ $c->NEXT::prepare_action( @_ );
+
+ $c->session; # this is OK
+ $c->sessionid; # this is also OK
+ }
+
=head1 CONFIGURATION
$c->config->{session} = {
=item verify_address
-When false, C<< $c->request->address >> will be checked at prepare time. If it
-is not the same as the address that initiated the session, the session is
-deleted.
+When true, C<<$c->request->address>> will be checked at prepare time. If it is
+not the same as the address that initiated the session, the session is deleted.
+
+Defaults to false.
+
+=item flash_to_stash
+
+This option makes it easier to have actions behave the same whether they were
+forwarded to or redirected to. On prepare time it copies the contents of
+C<flash> (if any) to the stash.
=back
=item __expires
-A timestamp whose value is the last second when the session is still valid. If
-a session is restored, and __expires is less than the current time, the session
-is deleted.
+This key no longer exists. Use C<session_expires> instead.
=item __updated
-The last time a session was saved. This is the value of
-C<< $c->{session}{__expires} - $c->config->{session}{expires} >>.
+The last time a session was saved to the store.
=item __created
=item __address
The value of C<< $c->request->address >> at the time the session was created.
-This value is only populated of C<verify_address> is true in the configuration.
+This value is only populated if C<verify_address> is true in the configuration.
=back
=head1 CAVEATS
+=head2 Round the Robin Proxies
+
C<verify_address> could make your site inaccessible to users who are behind
load balanced proxies. Some ISPs may give a different IP to each request by the
same client due to this type of proxying. If addresses are verified these
To let these users access your site you can either disable address verification
as a whole, or provide a checkbox in the login dialog that tells the server
that it's OK for the address of the client to change. When the server sees that
-this box is checked it should delete the C<__address> sepcial key from the
+this box is checked it should delete the C<__address> special key from the
session hash when the hash is first created.
+=head2 Race Conditions
+
+In this day and age where cleaning detergents and Dutch football (not the
+American kind) teams roam the plains in great numbers, requests may happen
+simultaneously. This means that there is some risk of session data being
+overwritten, like this:
+
+=over 4
+
+=item 1.
+
+request a starts, request b starts, with the same session ID
+
+=item 2.
+
+session data is loaded in request a
+
+=item 3.
+
+session data is loaded in request b
+
+=item 4.
+
+session data is changed in request a
+
+=item 5.
+
+request a finishes, session data is updated and written to store
+
+=item 6.
+
+request b finishes, session data is updated and written to store, overwriting
+changes by request a
+
+=back
+
+If this is a concern in your application, a soon-to-be-developed locking
+solution is the only safe way to go. This will have a bigger overhead.
+
+For applications where any given user is only making one request at a time this
+plugin should be safe enough.
+
+=head1 AUTHORS
+
+Andy Grundman
+
+Christian Hansen
+
+Yuval Kogman, C<nothingmuch@woobling.org>
+
+Sebastian Riedel
+
+Tomas Doran (t0m) C<bobtfish@bobtfish.net> (current maintainer)
+
+Sergio Salvi
+
+And countless other contributers from #catalyst. Thanks guys!
+
+=head1 COPYRIGHT & LICENSE
+
+ Copyright (c) 2005 the aforementioned authors. All rights
+ reserved. This program is free software; you can redistribute
+ it and/or modify it under the same terms as Perl itself.
+
=cut