cookies.pm

1. 记录每个帖子的访问人情况

=item $cookie_jar->set_cookie($version, $key, $val, $path, $domain, $port, $path_spec, $secure, $maxage, $discard, \%rest)

The set_cookie() method updates the state of the $cookie_jar.  The
$key, $val, $domain, $port and $path arguments are strings.  The
$path_spec, $secure, $discard arguments are boolean values. The $maxage
value is a number indicating number of seconds that this cookie will
live.  A value <= 0 will delete this cookie.  %rest defines
various other attributes like "Comment" and "CommentURL".

=cut

sub set_cookie
{
    my $self = shift;
    my($version,
       $key, $val, $path, $domain, $port,
       $path_spec, $secure, $maxage, $discard, $rest) = @_;

    # path and key can not be empty (key can't start with '$')
    return $self if !defined($path) || $path !~ m,^/, ||
	            !defined($key)  || $key  !~ m,[^\$],;

    # ensure legal port
    if (defined $port) {
	return $self unless $port =~ /^_?\d+(?:,\d+)*$/;
    }

    my $expires;
    if (defined $maxage) {
	if ($maxage <= 0) {
	    delete $self->{COOKIES}{$domain}{$path}{$key};
	    return $self;
	}
	$expires = time() + $maxage;
    }
    $version = 0 unless defined $version;

    my @array = ($version, $val,$port,
		 $path_spec,
		 $secure, $expires, $discard);
    push(@array, {%$rest}) if defined($rest) && %$rest;
    # trim off undefined values at end
    pop(@array) while !defined $array[-1];

    $self->{COOKIES}{$domain}{$path}{$key} = \@array;
    $self;
}

=item $cookie_jar->save( [$file] );

This method file saves the state of the $cookie_jar to a file.
The state can then be restored later using the load() method.  If a
filename is not specified we will use the name specified during
construction.  If the attribute I<ignore_discared> is set, then we
will even save cookies that are marked to be discarded.

The default is to save a sequence of "Set-Cookie3" lines.
"Set-Cookie3" is a proprietary LWP format, not known to be compatible
with any browser.  The I<HTTP::Cookies::Netscape> sub-class can
be used to save in a format compatible with Netscape.

=cut

sub save
{
    my $self = shift;
    my $file = shift || $self->{'file'} || return;
    local(*FILE);
    open(FILE, ">$file") or die "Can't open $file: $!";
    print FILE "#LWP-Cookies-1.0\n";
    print FILE $self->as_string(!$self->{ignore_discard});
    close(FILE);
    1;
}

=item $cookie_jar->load( [$file] );

This method reads the cookies from the file and adds them to the
$cookie_jar.  The file must be in the format written by the save()
method.

=cut

sub load
{
    my $self = shift;
    my $file = shift || $self->{'file'} || return;
    local(*FILE, $_);
    local $/ = "\n";  # make sure we got standard record separator
    open(FILE, $file) or return;
    my $magic = <FILE>;
    unless ($magic =~ /^\#LWP-Cookies-(\d+\.\d+)/) {
	warn "$file does not seem to contain cookies";
	return;
    }
    while (<FILE>) {
	next unless s/^Set-Cookie3:\s*//;
	chomp;
	my $cookie;
	for $cookie (split_header_words($_)) {
	    my($key,$val) = splice(@$cookie, 0, 2);
	    my %hash;
	    while (@$cookie) {
		my $k = shift @$cookie;
		my $v = shift @$cookie;
		$hash{$k} = $v;
	    }
	    my $version   = delete $hash{version};
	    my $path      = delete $hash{path};
	    my $domain    = delete $hash{domain};
	    my $port      = delete $hash{port};
	    my $expires   = str2time(delete $hash{expires});

	    my $path_spec = exists $hash{path_spec}; delete $hash{path_spec};
	    my $secure    = exists $hash{secure};    delete $hash{secure};
	    my $discard   = exists $hash{discard};   delete $hash{discard};

	    my @array =	($version,$val,$port,
			 $path_spec,$secure,$expires,$discard);
	    push(@array, \%hash) if %hash;
	    $self->{COOKIES}{$domain}{$path}{$key} = \@array;
	}
    }
    close(FILE);
    1;
}

=item $cookie_jar->revert;

This method empties the $cookie_jar and re-loads the $cookie_jar
from the last save file.

=cut

sub revert
{
    my $self = shift;
    $self->clear->load;
    $self;
}

=item $cookie_jar->clear( [$domain, [$path, [$key] ] ]);

Invoking this method without arguments will empty the whole
$cookie_jar.  If given a single argument only cookies belonging to
that domain will be removed.  If given two arguments, cookies
belonging to the specified path within that domain are removed.  If
given three arguments, then the cookie with the specified key, path
and domain is removed.

=cut

sub clear
{
    my $self = shift;
    if (@_ == 0) {
	$self->{COOKIES} = {};
    } elsif (@_ == 1) {
	delete $self->{COOKIES}{$_[0]};
    } elsif (@_ == 2) {
	delete $self->{COOKIES}{$_[0]}{$_[1]};
    } elsif (@_ == 3) {
	delete $self->{COOKIES}{$_[0]}{$_[1]}{$_[2]};
    } else {
	require Carp;
        Carp::carp('Usage: $c->clear([domain [,path [,key]]])');
    }
    $self;
}

=item $cookie_jar->clear_temporary_cookies( );

Discard all temporary cookies. Scans for all cookies in the jar 
with either no expire field or a true C<discard> flag. To be 
called when the user agent shuts down according to RFC 2965.

=cut

sub clear_temporary_cookies
{
    my($self) = @_;

    $self->scan(sub {
        if($_[9] or        # "Discard" flag set
           not $_[8]) {    # No expire field?
            $_[8] = -1;            # Set the expire/max_age field
            $self->set_cookie(@_); # Clear the cookie
        }
      });
}

sub DESTROY
{
    my $self = shift;
    $self->save if $self->{'autosave'};
}


=item $cookie_jar->scan( \&callback );

The argument is a subroutine that will be invoked for each cookie
stored in the $cookie_jar.  The subroutine will be invoked with
the following arguments:

  0  version
  1  key
  2  val
  3  path
  4  domain
  5  port
  6  path_spec
  7  secure
  8  expires
  9  discard
 10  hash

=cut

sub scan
{
    my($self, $cb) = @_;
    my($domain,$path,$key);
    for $domain (sort keys %{$self->{COOKIES}}) {
	for $path (sort keys %{$self->{COOKIES}{$domain}}) {
	    for $key (sort keys %{$self->{COOKIES}{$domain}{$path}}) {
		my($version,$val,$port,$path_spec,
		   $secure,$expires,$discard,$rest) =
		       @{$self->{COOKIES}{$domain}{$path}{$key}};
		$rest = {} unless defined($rest);
		&$cb($version,$key,$val,$path,$domain,$port,
		     $path_spec,$secure,$expires,$discard,$rest);
	    }
	}
    }
}

=item $cookie_jar->as_string( [$skip_discard] );

The as_string() method will return the state of the $cookie_jar
represented as a sequence of "Set-Cookie3" header lines separated by
"\n".  If $skip_discard is TRUE, it will not return lines for
cookies with the I<Discard> attribute.

=cut

sub as_string
{
    my($self, $skip_discard) = @_;
    my @res;
    $self->scan(sub {
	my($version,$key,$val,$path,$domain,$port,
	   $path_spec,$secure,$expires,$discard,$rest) = @_;
	return if $discard && $skip_discard;
	my @h = ($key, $val);
	push(@h, "path", $path);
	push(@h, "domain" => $domain);
	push(@h, "port" => $port) if defined $port;
	push(@h, "path_spec" => undef) if $path_spec;
	push(@h, "secure" => undef) if $secure;
	push(@h, "expires" => HTTP::Date::time2isoz($expires)) if $expires;
	push(@h, "discard" => undef) if $discard;
	my $k;
	for $k (sort keys %$rest) {
	    push(@h, $k, $rest->{$k});
	}
	push(@h, "version" => $version);
	push(@res, "Set-Cookie3: " . join_header_words(\@h));
    });
    join("\n", @res, "");
}

sub _host
{
    my($request, $url) = @_;
    if (my $h = $request->header("Host")) {
	$h =~ s/:\d+$//;  # might have a port as well
	return $h;
    }
    return $url->host;
}

sub _url_path
{
    my $url = shift;
    my $path;
    if($url->can('epath')) {
       $path = $url->epath;    # URI::URL method
    } else {
       $path = $url->path;           # URI::_generic method
    }
    $path = "/" unless length $path;
    $path;
}

sub _normalize_path  # so that plain string compare can be used
{
    my $x;
    $_[0] =~ s/%([0-9a-fA-F][0-9a-fA-F])/
	         $x = uc($1);
                 $x eq "2F" || $x eq "25" ? "%$x" :
                                            pack("C", hex($x));
              /eg;
    $_[0] =~ s/([\0-\x20\x7f-\xff])/sprintf("%%%02X",ord($1))/eg;
}



=back

=head1 SUB CLASSES

We also provide a subclass called I<HTTP::Cookies::Netscape> which
loads and saves Netscape compatible cookie files.  You
should be able to have LWP share Netscape's cookies by constructing
your $cookie_jar like this:

 $cookie_jar = HTTP::Cookies::Netscape->new(
                   File     => "$ENV{HOME}/.netscape/cookies",
                   AutoSave => 1,
               );

Please note that the Netscape cookie file format is not able to store
all the information available in the Set-Cookie2 headers, so you will
probably loose some information if you save in this format.

=cut

package HTTP::Cookies::Netscape;

use vars qw(@ISA);
@ISA=qw(HTTP::Cookies);

sub load
{
    my($self, $file) = @_;
    $file ||= $self->{'file'} || return;
    local(*FILE, $_);
    local $/ = "\n";  # make sure we got standard record separator
    my @cookies;
    open(FILE, $file) || return;
    my $magic = <FILE>;
    unless ($magic =~ /^\# Netscape HTTP Cookie File/) {
	warn "$file does not look like a netscape cookies file" if $^W;
	close(FILE);
	return;
    }
    my $now = time() - $EPOCH_OFFSET;
    while (<FILE>) {
	next if /^\s*\#/;
	next if /^\s*$/;
	chomp;
	my($domain,$bool1,$path,$secure, $expires,$key,$val) = split(/\t/, $_);
	$secure = ($secure eq "TRUE");
	$self->set_cookie(undef,$key,$val,$path,$domain,undef,
			  0,$secure,$expires-$now, 0);
    }
    close(FILE);
    1;
}

sub save
{
    my($self, $file) = @_;
    $file ||= $self->{'file'} || return;
    local(*FILE, $_);
    open(FILE, ">$file") || return;

    print FILE <<EOT;
# Netscape HTTP Cookie File
# http://www.netscape.com/newsref/std/cookie_spec.html
# This is a generated file!  Do not edit.

EOT

    my $now = time - $EPOCH_OFFSET;
    $self->scan(sub {
	my($version,$key,$val,$path,$domain,$port,
	   $path_spec,$secure,$expires,$discard,$rest) = @_;
	return if $discard && !$self->{ignore_discard};
	$expires = $expires ? $expires - $EPOCH_OFFSET : 0;
	return if $now > $expires;
	$secure = $secure ? "TRUE" : "FALSE";
	my $bool = $domain =~ /^\./ ? "TRUE" : "FALSE";
	print FILE join("\t", $domain, $bool, $path, $secure, $expires, $key, $val), "\n";
    });
    close(FILE);
    1;
}

1;

__END__

=head1 COPYRIGHT

Copyright 1997-1999 Gisle Aas

This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=cut