CGI::Cookie(3pm)					 Perl Programmers Reference Guide					  CGI::Cookie(3pm)

NAME

       CGI::Cookie - Interface to HTTP Cookies

SYNOPSIS

	   use CGI qw/:standard/;
	   use CGI::Cookie;

	   # Create new cookies and send them
	   $cookie1 = CGI::Cookie->new(-name=>'ID',-value=>123456);
	   $cookie2 = CGI::Cookie->new(-name=>'preferences',
				      -value=>{ font => Helvetica,
						size => 12 }
				      );
	   print header(-cookie=>[$cookie1,$cookie2]);

	   # fetch existing cookies
	   %cookies = CGI::Cookie->fetch;
	   $id = $cookies{'ID'}->value;

	   # create cookies returned from an external source
	   %cookies = CGI::Cookie->parse($ENV{COOKIE});

DESCRIPTION

       CGI::Cookie is an interface to HTTP/1.1 cookies, an innovation that allows Web servers to store persistent information on the browser's
       side of the connection.	Although CGI::Cookie is intended to be used in conjunction with CGI.pm (and is in fact used by it internally), you
       can use this module independently.

       For full information on cookies see

	       http://tools.ietf.org/html/rfc2109
	       http://tools.ietf.org/html/rfc2965
	       http://tools.ietf.org/html/draft-ietf-httpstate-cookie

USING CGI
::Cookie
       CGI::Cookie is object oriented.	Each cookie object has a name and a value.  The name is any scalar value.  The value is any scalar or
       array value (associative arrays are also allowed).  Cookies also have several optional attributes, including:

       1. expiration date
	   The expiration date tells the browser how long to hang on to the cookie.  If the cookie specifies an expiration date in the future, the
	   browser will store the cookie information in a disk file and return it to the server every time the user reconnects (until the
	   expiration date is reached).  If the cookie species an expiration date in the past, the browser will remove the cookie from the disk
	   file.  If the expiration date is not specified, the cookie will persist only until the user quits the browser.

       2. domain
	   This is a partial or complete domain name for which the cookie is valid.  The browser will return the cookie to any host that matches
	   the partial domain name.  For example, if you specify a domain name of ".capricorn.com", then the browser will return the cookie to Web
	   servers running on any of the machines "www.capricorn.com", "ftp.capricorn.com", "feckless.capricorn.com", etc.  Domain names must
	   contain at least two periods to prevent attempts to match on top level domains like ".edu".	If no domain is specified, then the
	   browser will only return the cookie to servers on the host the cookie originated from.

       3. path
	   If you provide a cookie path attribute, the browser will check it against your script's URL before returning the cookie.  For example,
	   if you specify the path "/cgi-bin", then the cookie will be returned to each of the scripts "/cgi-bin/tally.pl", "/cgi-bin/order.pl",
	   and "/cgi-bin/customer_service/complain.pl", but not to the script "/cgi-private/site_admin.pl".  By default, the path is set to "/",
	   so that all scripts at your site will receive the cookie.

       4. secure flag
	   If the "secure" attribute is set, the cookie will only be sent to your script if the CGI request is occurring on a secure channel, such
	   as SSL.

       5. httponly flag
	   If the "httponly" attribute is set, the cookie will only be accessible through HTTP Requests. This cookie will be inaccessible via
	   JavaScript (to prevent XSS attacks).

	   This feature is only supported by recent browsers like Internet Explorer 6 Service Pack 1, Firefox 3.0 and Opera 9.5 (and later of
	   course).

	   See these URLs for more information:

		   http://msdn.microsoft.com/en-us/library/ms533046.aspx
		   http://www.owasp.org/index.php/HTTPOnly#Browsers_Supporting_HTTPOnly

   Creating New Cookies
	       my $c = CGI::Cookie->new(-name	 =>  'foo',
				    -value   =>  'bar',
				    -expires =>  '+3M',
				    -domain  =>  '.capricorn.com',
				    -path    =>  '/cgi-bin/database',
				    -secure  =>  1
				   );

       Create cookies from scratch with the new method.  The -name and -value parameters are required.	The name must be a scalar value.  The
       value can be a scalar, an array reference, or a hash reference.	(At some point in the future cookies will support one of the Perl object
       serialization protocols for full generality).

       -expires accepts any of the relative or absolute date formats recognized by CGI.pm, for example "+3M" for three months in the future.  See
       CGI.pm's documentation for details.

       -max-age accepts the same data formats as -expires, but sets a relative value instead of an absolute like -expires. This is intended to be
       more secure since a clock could be changed to fake an absolute time. In practice, as of 2011, "-max-age" still does not enjoy the
       widespread support that "-expires" has. You can set both, and browsers that support "-max-age" should ignore the "Expires" header. The
       drawback to this approach is the bit of bandwidth for sending an extra header on each cookie.

       -domain points to a domain name or to a fully qualified host name.  If not specified, the cookie will be returned only to the Web server
       that created it.

       -path points to a partial URL on the current server.  The cookie will be returned to all URLs beginning with the specified path.  If not
       specified, it defaults to '/', which returns the cookie to all pages at your site.

       -secure if set to a true value instructs the browser to return the cookie only when a cryptographic protocol is in use.

       -httponly if set to a true value, the cookie will not be accessible via JavaScript.

       For compatibility with Apache::Cookie, you may optionally pass in a mod_perl request object as the first argument to "new()". It will
       simply be ignored:

	 my $c = CGI::Cookie->new($r,
				 -name	  =>  'foo',
				 -value   =>  ['bar','baz']);

   Sending the Cookie to the Browser
       The simplest way to send a cookie to the browser is by calling the bake() method:

	 $c->bake;

       This will print the Set-Cookie HTTP header to STDOUT using CGI.pm. CGI.pm will be loaded for this purpose if it is not already. Otherwise
       CGI.pm is not required or used by this module.

       Under mod_perl, pass in an Apache request object:

	 $c->bake($r);

       If you want to set the cookie yourself, Within a CGI script you can send a cookie to the browser by creating one or more Set-Cookie: fields
       in the HTTP header.  Here is a typical sequence:

	 my $c = CGI::Cookie->new(-name    =>  'foo',
				 -value   =>  ['bar','baz'],
				 -expires =>  '+3M');

	 print "Set-Cookie: $c
";
	 print "Content-Type: text/html

";

       To send more than one cookie, create several Set-Cookie: fields.

       If you are using CGI.pm, you send cookies by providing a -cookie argument to the header() method:

	 print header(-cookie=>$c);

       Mod_perl users can set cookies using the request object's header_out() method:

	 $r->headers_out->set('Set-Cookie' => $c);

       Internally, Cookie overloads the "" operator to call its as_string() method when incorporated into the HTTP header.  as_string() turns the
       Cookie's internal representation into an RFC-compliant text representation.  You may call as_string() yourself if you prefer:

	 print "Set-Cookie: ",$c->as_string,"
";

   Recovering Previous Cookies
	       %cookies = CGI::Cookie->fetch;

       fetch returns an associative array consisting of all cookies returned by the browser.  The keys of the array are the cookie names.  You can
       iterate through the cookies this way:

	       %cookies = CGI::Cookie->fetch;
	       for (keys %cookies) {
		  do_something($cookies{$_});
	       }

       In a scalar context, fetch() returns a hash reference, which may be more efficient if you are manipulating multiple cookies.

       CGI.pm uses the URL escaping methods to save and restore reserved characters in its cookies.  If you are trying to retrieve a cookie set by
       a foreign server, this escaping method may trip you up.	Use raw_fetch() instead, which has the same semantics as fetch(), but performs no
       unescaping.

       You may also retrieve cookies that were stored in some external form using the parse() class method:

	      $COOKIES = `cat /usr/tmp/Cookie_stash`;
	      %cookies = CGI::Cookie->parse($COOKIES);

       If you are in a mod_perl environment, you can save some overhead by passing the request object to fetch() like this:

	  CGI::Cookie->fetch($r);

       If the value passed to parse() is undefined, an empty array will returned in list contact, and an empty hashref will be returned in scalar
       context.

   Manipulating Cookies
       Cookie objects have a series of accessor methods to get and set cookie attributes.  Each accessor has a similar syntax.	Called without
       arguments, the accessor returns the current value of the attribute.  Called with an argument, the accessor changes the attribute and
       returns its new value.

       name()
	   Get or set the cookie's name.  Example:

		   $name = $c->name;
		   $new_name = $c->name('fred');

       value()
	   Get or set the cookie's value.  Example:

		   $value = $c->value;
		   @new_value = $c->value(['a','b','c','d']);

	   value() is context sensitive.  In a list context it will return the current value of the cookie as an array.  In a scalar context it
	   will return the first value of a multivalued cookie.

       domain()
	   Get or set the cookie's domain.

       path()
	   Get or set the cookie's path.

       expires()
	   Get or set the cookie's expiration time.

AUTHOR INFORMATION

       Copyright 1997-1998, Lincoln D. Stein.  All rights reserved.

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

       Address bug reports and comments to: lstein@cshl.org

BUGS

       This section intentionally left blank.

SEE ALSO

       CGI::Carp, CGI

       RFC 2109 <http://www.ietf.org/rfc/rfc2109.txt>, RFC 2695 <http://www.ietf.org/rfc/rfc2965.txt>

perl v5.16.2							    2012-10-25							  CGI::Cookie(3pm)