CGI::Cookie

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



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) 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://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 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 Netscape 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, path is
           set to "/", which causes the cookie to be sent to any CGI script on
           your site.

       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
       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.

       -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.

       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.
       Alternatively, you may concatenate the cookies together with "; " and
       send them in one field.

       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:

         $r->header_out('Set-Cookie',$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 cookies returned
       by the browser.  The keys of the array are the cookie names.  You can
       iterate through the cookies this way:

               %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 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:

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


       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 an array 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
       be used and modified freely, but I do request that this copyright
       notice remain attached to the file.  You may modify this module as you
       wish, but if you redistribute a modified version, please attach a note
       listing the modifications you have made.

       Address bug reports and comments to: lstein@genome.wi.mit.edu

BUGS
       This section intentionally left blank.

SEE ALSO
       the CGI::Carp manpage, the CGI manpage

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3rd Berkeley Distribution    perl 5.005, patch 02               CGI::Cookie(3)