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


NAME
       CGI::Cookie - Interface to Netscape Cookies

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

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

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

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

DESCRIPTION
       CGI::Cookie is an interface to Netscape (HTTP/1.1) cook-
       ies, an innovation that allows Web servers to store per-
       sistent information on the browser's side of the connec-
       tion.  Although CGI::Cookie is intended to be used in con-
       junction with CGI.pm (and is in fact used by it inter-
       nally), you can use this module independently.

       For full information on cookies see

               http://www.ics.uci.edu/pub/ietf/http/rfc2109.txt

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 expira-
           tion 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 expi-
           ration 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.





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


       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 Netscape will return the cookie
           to Web servers running on any of the machines
           "www.capricorn.com", "ftp.capricorn.com", "feck-
           less.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 speci-
           fied, 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 return-
           ing 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_ser-
           vice/complain.pl", but not to the script "/cgi-pri-
           vate/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.

       Creating New Cookies

               $c = new CGI::Cookie(-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 serial-
       ization protocols for full generality).

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

       -domain points to a domain name or to a fully qualified



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


       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.

       Sending the Cookie to the Browser

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

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

       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,"\n";

       Recovering Previous Cookies

               %cookies = fetch CGI::Cookie;

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



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


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

       In a scalar context, fetch() returns a hash reference,
       which may be more efficient if you are manipulating multi-
       ple 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:

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

       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 argu-
       ment, 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.




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


       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: lsteinATcshl.org

BUGS
       This section intentionally left blank.

SEE ALSO
       CGI::Carp, CGI


































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