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CGI::Cookie(3)        User Contributed Perl Documentation       CGI::Cookie(3)
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, a mechanism 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
           https://tools.ietf.org/html/rfc6265
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 supported by nearly all modern browsers.
           See these URLs for more information:
               http://msdn.microsoft.com/en-us/library/ms533046.aspx
               http://www.browserscope.org/?category=security&v=top
       6. samesite flag
           Allowed settings are "Strict" and "Lax".
           As of June 2016, support is limited to recent releases of Chrome
           and Opera.
           <https://tools.ietf.org/html/draft-west-first-party-cookies-07>;
   Creating New Cookies
               my $c = CGI::Cookie->new(-name    =>  'foo',
                                    -value   =>  'bar',
                                    -expires =>  '+3M',
                                  '-max-age' =>  '+3M',
                                    -domain  =>  '.capricorn.com',
                                    -path    =>  '/cgi-bin/database',
                                    -secure  =>  1,
                                    -samesite=>  "Lax"
                                   );
       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.
       -samesite may be "Lax" or "Strict" and is an evolving part of the
       standards for cookies. Please refer to current documentation regarding
       it.
       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: $c\n";
         print "Content-Type: text/html\n\n";
       To send more than one cookie, create several Set-Cookie: fields.
       If you are using CGI.pm, you send cookies by providing a -cookie
       argument to the header() method:
         print header(-cookie=>$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 = 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 context, 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.
       max_age()
           Get or set the cookie's max_age value.
AUTHOR INFORMATION
       The CGI.pm distribution is copyright 1995-2007, Lincoln D. Stein. It is
       distributed under GPL and the Artistic License 2.0. It is currently
       maintained by Lee Johnson with help from many contributors.
       Address bug reports and comments to:
       https://github.com/leejo/CGI.pm/issues
       The original bug tracker can be found at:
       https://rt.cpan.org/Public/Dist/Display.html?Queue=CGI.pm
       When sending bug reports, please provide the version of CGI.pm, the
       version of Perl, the name and version of your Web server, and the name
       and version of the operating system you are using.  If the problem is
       even remotely browser dependent, please provide information about the
       affected browsers as well.
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 v5.26.3                      2017-12-01                    CGI::Cookie(3)