1CGI::Simple::Cookie(3)User Contributed Perl DocumentationCGI::Simple::Cookie(3)
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6 CGI::Simple::Cookie - Interface to HTTP cookies
7
9 use CGI::Simple::Standard qw(header);
10 use CGI::Simple::Cookie;
11 # Create new cookies and send them
13 $cookie1 = CGI::Simple::Cookie->new( -name=>'ID', -value=>123456 );
14 $cookie2 = CGI::Simple::Cookie->new( -name=>'preferences',
15 -value=>{ font => Helvetica,
16 size => 12 }
17 );
18 print header( -cookie=>[$cookie1,$cookie2] );
19 # fetch existing cookies
21 %cookies = CGI::Simple::Cookie->fetch;
22 $id = $cookies{'ID'}->value;
23 # create cookies returned from an external source
25 %cookies = CGI::Simple::Cookie->parse($ENV{COOKIE});
26
28 CGI::Simple::Cookie is an interface to HTTP/1.1 cookies, a mechanism
29 that allows Web servers to store persistent information on the
30 browser's side of the connection. Although CGI::Simple::Cookie is
31 intended to be used in conjunction with CGI::Simple (and is in fact
32 used by it internally), you can use this module independently.
33 For full information on cookies see:
35 http://tools.ietf.org/html/rfc2109
37 http://tools.ietf.org/html/rfc2965
38
40 CGI::Simple::Cookie is object oriented. Each cookie object has a name
41 and a value. The name is any scalar value. The value is any scalar or
42 array value (associative arrays are also allowed). Cookies also have
43 several optional attributes, including:
44 1. expiration date
46 The expiration date tells the browser how long to hang on to the
47 cookie. If the cookie specifies an expiration date in the future,
48 the browser will store the cookie information in a disk file and
49 return it to the server every time the user reconnects (until the
50 expiration date is reached). If the cookie species an expiration
51 date in the past, the browser will remove the cookie from the disk
52 file. If the expiration date is not specified, the cookie will
53 persist only until the user quits the browser.
54 2. domain
56 This is a partial or complete domain name for which the cookie is
57 valid. The browser will return the cookie to any host that matches
58 the partial domain name. For example, if you specify a domain name
59 of ".capricorn.com", then the browser will return the cookie to web
60 servers running on any of the machines "www.capricorn.com",
61 "ftp.capricorn.com", "feckless.capricorn.com", etc. Domain names
62 must contain at least two periods to prevent attempts to match on
63 top level domains like ".edu". If no domain is specified, then the
64 browser will only return the cookie to servers on the host the
65 cookie originated from.
66 3. path
68 If you provide a cookie path attribute, the browser will check it
69 against your script's URL before returning the cookie. For
70 example, if you specify the path "/cgi-bin", then the cookie will
71 be returned to each of the scripts "/cgi-bin/tally.pl",
72 "/cgi-bin/order.pl", and "/cgi-bin/customer_service/complain.pl",
73 but not to the script "/cgi-private/site_admin.pl". By default,
74 the path is set to "/", so that all scripts at your site will
75 receive the cookie.
76 4. secure flag
78 If the "secure" attribute is set, the cookie will only be sent to
79 your script if the CGI request is occurring on a secure channel,
80 such as SSL.
81 5. HttpOnly flag
83 If the "httponly" attribute is set, the cookie will only be
84 accessible through HTTP Requests. This cookie will be inaccessible
85 via JavaScript (to prevent XSS attacks).
86 See this URL for more information including supported browsers:
88 <http://www.owasp.org/index.php/HTTPOnly>
90 6. samesite flag
92 Allowed settings are "Strict" and "Lax".
93 As of April 2018, support is limited mostly to recent releases of
95 Chrome and Opera.
96 <https://tools.ietf.org/html/draft-west-first-party-cookies-07>
98 Creating New Cookies
100 $c = CGI::Simple::Cookie->new( -name => 'foo',
101 -value => 'bar',
102 -expires => '+3M',
103 -max-age => '+3M',
104 -domain => '.capricorn.com',
105 -path => '/cgi-bin/database',
106 -secure => 1,
107 -samesite => 'Lax',
108 );
109 Create cookies from scratch with the new method. The -name and -value
111 parameters are required. The name must be a scalar value. The value
112 can be a scalar, an array reference, or a hash reference. (At some
113 point in the future cookies will support one of the Perl object
114 serialization protocols for full generality).
115 -expires accepts any of the relative or absolute date formats
117 recognized by CGI::Simple, for example "+3M" for three months in the
118 future. See CGI::Simple's documentation for details.
119 -max-age accepts the same data formats as -expires, but sets a relative
121 value instead of an absolute like -expires. This is intended to be more
122 secure since a clock could be changed to fake an absolute time. In
123 practice, as of 2011, "-max-age" still does not enjoy the widespread
124 support that "-expires" has. You can set both, and browsers that
125 support "-max-age" should ignore the "Expires" header. The drawback to
126 this approach is the bit of bandwidth for sending an extra header on
127 each cookie.
128 -domain points to a domain name or to a fully qualified host name. If
130 not specified, the cookie will be returned only to the Web server that
131 created it.
132 -path points to a partial URL on the current server. The cookie will
134 be returned to all URLs beginning with the specified path. If not
135 specified, it defaults to '/', which returns the cookie to all pages at
136 your site.
137 -secure if set to a true value instructs the browser to return the
139 cookie only when a cryptographic protocol is in use.
140 -httponly if set to a true value, the cookie will not be accessible via
142 JavaScript.
143 -samesite may be "Lax" or "Strict" and is an evolving part of the
145 standards for cookies. Please refer to current documentation regarding
146 it.
147 Sending the Cookie to the Browser
149 Within a CGI script you can send a cookie to the browser by creating
150 one or more Set-Cookie: fields in the HTTP header. Here is a typical
151 sequence:
152 $c = CGI::Simple::Cookie->new( -name => 'foo',
154 -value => ['bar','baz'],
155 -expires => '+3M'
156 );
157 print "Set-Cookie: $c\n";
159 print "Content-Type: text/html\n\n";
160 To send more than one cookie, create several Set-Cookie: fields.
162 Alternatively, you may concatenate the cookies together with "; " and
163 send them in one field.
164 If you are using CGI::Simple, you send cookies by providing a -cookie
166 argument to the header() method:
167 print header( -cookie=>$c );
169 Mod_perl users can set cookies using the request object's header_out()
171 method:
172 $r->header_out('Set-Cookie',$c);
174 Internally, Cookie overloads the "" operator to call its as_string()
176 method when incorporated into the HTTP header. as_string() turns the
177 Cookie's internal representation into an RFC-compliant text
178 representation. You may call as_string() yourself if you prefer:
179 print "Set-Cookie: ",$c->as_string,"\n";
181 Recovering Previous Cookies
183 %cookies = CGI::Simple::Cookie->fetch;
184 fetch returns an associative array consisting of all cookies returned
186 by the browser. The keys of the array are the cookie names. You can
187 iterate through the cookies this way:
188 %cookies = CGI::Simple::Cookie->fetch;
190 foreach (keys %cookies) {
191 do_something($cookies{$_});
192 }
193 In a scalar context, fetch() returns a hash reference, which may be
195 more efficient if you are manipulating multiple cookies.
196 CGI::Simple uses the URL escaping methods to save and restore reserved
198 characters in its cookies. If you are trying to retrieve a cookie set
199 by a foreign server, this escaping method may trip you up. Use
200 raw_fetch() instead, which has the same semantics as fetch(), but
201 performs no unescaping.
202 You may also retrieve cookies that were stored in some external form
204 using the parse() class method:
205 $COOKIES = `cat /usr/tmp/Cookie_stash`;
207 %cookies = CGI::Simple::Cookie->parse($COOKIES);
208 Manipulating Cookies
210 Cookie objects have a series of accessor methods to get and set cookie
211 attributes. Each accessor has a similar syntax. Called without
212 arguments, the accessor returns the current value of the attribute.
213 Called with an argument, the accessor changes the attribute and returns
214 its new value.
215 name()
217 Get or set the cookie's name. Example:
218 $name = $c->name;
220 $new_name = $c->name('fred');
221 value()
223 Get or set the cookie's value. Example:
224 $value = $c->value;
226 @new_value = $c->value(['a','b','c','d']);
227 value() is context sensitive. In a list context it will return the
229 current value of the cookie as an array. In a scalar context it
230 will return the first value of a multivalued cookie.
231 domain()
233 Get or set the cookie's domain.
234 path()
236 Get or set the cookie's path.
237 expires()
239 Get or set the cookie's expiration time.
240 max_age()
242 Get or set the cookie's maximum age.
243 secure()
245 Get or set the cookie's secure flag.
246 httponly()
248 Get or set the cookie's HttpOnly flag.
249 samesite()
251 Get or set the cookie's samesite value.
252
254 Original version copyright 1997-1998, Lincoln D. Stein. All rights
255 reserved. Originally copyright 2001 Dr James Freeman
256 <jfreeman@tassie.net.au> This release by Andy Armstrong
257 <andy@hexten.net>
258 This library is free software; you can redistribute it and/or modify it
260 under the same terms as Perl itself.
261 Address bug reports and comments to: andy@hexten.net
263
265 This section intentionally left blank :-)
266
268 CGI::Carp, CGI::Simple
269perl v5.30.1 2020-01-29 CGI::Simple::Cookie(3)