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setcookie (PHP 3, PHP 4, PHP 5) setcookie -- Send a cookie Descriptionbool setcookie ( string name [, string value [, int expire [, string path [, string domain [, bool secure]]]]] )
setcookie() defines a cookie to be sent along
with the rest of the HTTP headers. Like other headers, cookies
must be sent before any output from your
script (this is a protocol restriction). This requires that you
place calls to this function prior to any output, including
<html> and <head> tags
as well as any whitespace. If output exists prior to calling this
function, setcookie() will fail and return FALSE.
If setcookie() successfully runs, it will return
TRUE. This does not indicate whether the user accepted the cookie.
Замечание:
As of PHP 4, you can use output buffering to send output prior to the
call of this function, with the overhead of all of your output to the
browser being buffered in the server until you send it. You can do this
by calling ob_start() and
ob_end_flush() in your script, or setting the
output_buffering configuration directive on in your
php.ini or server configuration files.
All the arguments except the name argument
are optional. You may also replace an argument with an empty string
("") in order to skip that
argument. Because the expire
argument is integer, it cannot
be skipped with an empty string, use a zero (0)
instead. The following table explains each parameter of the
setcookie() function, be sure to read the
Netscape cookie specification for
specifics on how each setcookie() parameter works
and RFC 2965 for additional
information on how HTTP cookies work.
Таблица 1. setcookie() parameters explained | Parameter | Description | Examples |
|---|
| name |
The name of the cookie.
|
'cookiename' is called as $_COOKIE['cookiename']
| | value |
The value of the cookie. This value is stored on the clients
computer; do not store sensitive information.
|
Assuming the name is 'cookiename', this
value is retrieved through $_COOKIE['cookiename']
| | expire |
The time the cookie expires. This is a Unix timestamp so is
in number of seconds since the epoch. In other words, you'll
most likely set this with the time() function
plus the number of seconds before you want it to expire. Or
you might use mktime().
|
time()+60*60*24*30 will set the cookie to
expire in 30 days. If not set, the cookie will expire at
the end of the session (when the browser closes).
| | path |
The path on the server in which the cookie will be available on.
|
If set to '/', the cookie will be available
within the entire domain. If set to
'/foo/', the cookie will only be available
within the /foo/ directory and all
sub-directories such as /foo/bar/ of
domain. The default value is the
current directory that the cookie is being set in.
| | domain |
The domain that the cookie is available.
|
To make the cookie available on all subdomains of example.com
then you'd set it to '.example.com'. The
. is not required but makes it compatible
with more browsers. Setting it to www.example.com
will make the cookie only available in the www
subdomain. Refer to tail matching in the
spec for details.
| | secure |
Indicates that the cookie should only be transmitted over a
secure HTTPS connection. When set to TRUE, the
cookie will only be set if a secure connection exists. The default
is FALSE.
|
0 or 1
|
Once the cookies have been set, they can be accessed on the next page load
with the $_COOKIE or
$HTTP_COOKIE_VARS arrays. Note,
autoglobals
such as $_COOKIE became available in PHP
4.1.0.
$HTTP_COOKIE_VARS has existed since PHP 3. Cookie
values also exist in
$_REQUEST.
Замечание:
If the PHP directive register_globals
is set to on then cookie values will also be made into
variables. In our examples below, $TestCookie will
exist. It's recommended to use $_COOKIE.
Common Pitfalls:
Cookies will not become visible until the next loading of a page that
the cookie should be visible for. To test if a cookie was successfully
set, check for the cookie on a next loading page before the cookie
expires. Expire time is set via the expire
parameter. A nice way to debug the existence of cookies is by
simply calling print_r($_COOKIE);.
Cookies must be deleted with the same parameters as they were set with.
If the value argument is an empty string, or FALSE, and all other arguments
match a previous call to setcookie, then the cookie with the specified
name will be deleted from the remote client.
Because setting a cookie with a value of FALSE will try to delete the cookie,
you should not use boolean values. Instead, use 0 for FALSE
and 1 for TRUE.
Cookies names can be set as array names and will be available to your
PHP scripts as arrays but separate cookies are stored on the users
system. Consider explode() to set one cookie with
multiple names and values. It is not recommended to use
serialize() for this purpose, because it can result
in security holes.
In PHP 3, multiple calls to setcookie() in the same
script will be performed in reverse order. If you are trying to
delete one cookie before inserting another you should put the
insert before the delete. As of PHP 4, multiple calls to
setcookie() are performed in the order called.
Some examples follow how to send cookies:
Пример 1. setcookie() send example |
<?php
$value = 'something from somewhere';
setcookie("TestCookie", $value);
setcookie("TestCookie", $value, time()+3600); setcookie("TestCookie", $value, time()+3600, "/~rasmus/", ".example.com", 1);
?>
|
|
Note that the value portion of the cookie will automatically be
urlencoded when you send the cookie, and when it is received, it
is automatically decoded and assigned to a variable by the same
name as the cookie name. If you don't want this, you can use
setrawcookie() instead if you are using PHP 5. To see
the contents of our test cookie in a script, simply use one of the
following examples:
When deleting a cookie you should assure that the expiration date
is in the past, to trigger the removal mechanism in your browser.
Examples follow how to delete cookies sent in previous example:
Пример 2. setcookie() delete example |
<?php
setcookie ("TestCookie", "", time() - 3600);
setcookie ("TestCookie", "", time() - 3600, "/~rasmus/", ".example.com", 1);
?>
|
|
You may also set array cookies by using array notation in the
cookie name. This has the effect of setting as many cookies as
you have array elements, but when the cookie is received by your
script, the values are all placed in an array with the cookie's
name:
Пример 3. setcookie() and arrays |
<?php
setcookie("cookie[three]", "cookiethree");
setcookie("cookie[two]", "cookietwo");
setcookie("cookie[one]", "cookieone");
if (isset($_COOKIE['cookie'])) {
foreach ($_COOKIE['cookie'] as $name => $value) {
echo "$name : $value <br />\n";
}
}
?>
|
which prints
three : cookiethree
two : cookietwo
one : cookieone |
|
Замечание:
The following RFC's may also be useful:
RFC 2109 and
RFC 2695
You may notice the expire parameter takes on a
Unix timestamp, as opposed to the date format Wdy, DD-Mon-YYYY
HH:MM:SS GMT, this is because PHP does this conversion
internally.
expire is compared to the client's time which can
differ from server's time.
Замечание:
Microsoft Internet Explorer 4 with Service Pack 1 applied does
not correctly deal with cookies that have their path parameter
set.
Netscape Communicator 4.05 and Microsoft Internet Explorer 3.x
appear to handle cookies incorrectly when the path and time
are not set.
See also header(), setrawcookie()
and the cookies section.
setcookie
kael dot shipman at DONTSPAMIT! dot gmail dot com
13-Jul-2006 06:20
As I've interpreted it, only the cookies with a path set to the server name to which the request was made are available to the PHP superglobal $_COOKIE. If all were available, you'd probably have a huge security hole. Therefore, if you have a cookie on your computer set by www.cha.com, and you then visit www.fah.com, www.fah.com cannot see that your www.cha.com cookie exists (at least through the PHP $_COOKIE superglobal).
I've tested this in Safari and Firefox on Mac. I can't imagine that it would be any different on other browsers, as I thought that was specifically what the path parameters were for.
Bogumil Wirchanowicz
12-Jul-2006 05:14
You can simple read all cookies from client machine, with "foreach" and superglobal variable "$_COOKIE".
<?php
if (is_array($_COOKIE)) foreach($_COOKIE as $k=>$v){
echo 'Cookie name: '.$k.'; Cookie value: '.$v.';<br/>';
}
?>
(is_array is checking if $_COOKIE is initialized array).
Eric Mueller
08-Jul-2006 10:44
for some weird reason, on Safari, set_cookie doesn't work unless you specify all parameters. my code was flopping until I added a '0' at the end (for the 'secure' flag) and now, the cookie is being stored. weeeeird.
Olivier Jacquet
06-Jul-2006 08:09
To respond to the UTF-8 encoding post:
"Although I wish it were different, UTF-8 encoded scripts start output at the php tag declaration."
This is because many editors put a BOM (Byte Order Marker) at the beginning of a UTF-8 file. These 2 bytes also get send to the browser.
To solve this you can either remove the bytes from the file with a binary editor or turn on output_buffering.
In relation to setting cookies:
If you want to set cookies that need to be remembered forever you can use the PHP_INT_MAX constant.
setcookie("cookieName", $cookieValue, PHP_INT_MAX);
mrvanes at gmail dot com
06-Jun-2006 07:22
I just discovered that IE6 (6.0.2800.1106 at least) seems to have difficulties accepting cookies when the subdomain part of the URL is longer than 10 characters. This applies to automatic sessionid's as well (that's how I found out). So: Setting a cookie on a site named http://examples.test.com/ will work, doing the same on http://my_examples.test.com will fail (or at least, failed for me).
Tested it by snooping the outgoing traffic from the client: the GET request lacks the COOKIE: header in the last case. A closer inspection revealed that the cookie was never accepted in the first place: when the subdomain is longer than 10 characters, no cookiefile is created in the temporary internet files directory. Temporary cookies (like the PHP sessionid) have the same problem.
Firefox and Konqueror have no problem with this.
[Editor's note: Your comment is wrong. It is not the length of the hostname but the use of the underscore (_) char within it which makes IE (silently) freak out. The use of underscores in hostnames is an RFC violation and may very well not be supported at all by a browser, proxy or any http client.]
gareth at gw126 dot com
05-Jun-2006 07:38
You can use cookies to prevent a browser refresh repeating some action from a form post... (providing the client is cookie enabled!)
//Flag up repeat actions (like credit card transaction, etc)
if(count($_POST)>0) {
$lastpost= isset($_COOKIE['lastpost']) ? $_COOKIE['lastpost'] : '';
if($lastpost!=md5(serialize($_POST))) {
setcookie('lastpost', md5(serialize($_POST)));
$_POST['_REPEATED']=0;
} else {
$_POST['_REPEATED']=1;
}
}
//At this point, if $_POST['_REPEATED']==1, then the user
//has hit the refresh button; so don't do any actions that you don't
//want to repeat!
Hope that helps :)
Gareth
Ahmet Antmen ahmetantmen_at_msn_dot_com
19-May-2006 02:05
You can be sure about the cookie files contents weren't changed.
<?php
$Seperator = '--';
$uniqueID = 'Ju?hG&F0yh9?=/6*GVfd-d8u6f86hp';
$Data = 'Ahmet '.md5('123456789');
setcookie('VerifyUser', $Data.$Seperator.md5($Data.$uniqueID));
if ($_COOKIE) {
$Cut = explode($Seperator, $_COOKIE['VerifyUser']);
if (md5($Cut[0].$uniqueID) === $Cut[1]) {
$_COOKIE['VerifyUser'] = $Cut[0];
} else {
die('Cookie data is invalid!!!');
}
}
echo $_COOKIE['VerifyUser'];
?>
Create a unique id for your site and create a hash with md5($Data.$uniqueID). Attacker can understant that it must be re-hash after change cookie content.
But doesn't. Because cannot guess your unique id. Seperate your hash and data with seperator and send that cookie. Control that hash of returned value and your unique id's is same returned hash. Otherwise you have to stop attack. Sorry for my poor english!
matt at mattsoft dot net
04-May-2006 05:47
using time()-1 to delete (expire) a cookie only works if the client's clock is set exact. my testing showed some weird results with my clock set 1 second or so behind the server. 1 day or even just a few seconds ahead of the server's time and the cookie doesn't expire when it's suposed to.
my test:
setcookie('k',$k+1,time()-1);
echo $k;
setting the expire time to 0 makes it a browser session cookie, lasting forever, until the browser is closed. but setting the expire time to 1 is the lowest timestamp possible and is most likely to expire the cookie without any problems.
my fix:
setcookie('k',$k+1,1);
echo $k;
this is my theory. I'm not sure why no one else has thought of this problem or solution, and I'm still testing, but please email me your questions or comments.
Brian
10-Mar-2006 11:56
Firefox is following the real spec and does not decode '+' to space...in fact it further encodes them to '%2B' to store the cookie. If you read a cookie using javascript and unescape it, all your spaces will be turned to '+'.
To fix this problem, use setrawcookie and rawurlencode:
setrawcookie('cookie_name', rawurlencode($value), time()+60*60*24*365);
The only change is that spaces will be encoded to '%20' instead of '+' and will now decode properly.
php at macros dot org
02-Mar-2006 05:19
I've just been fighting with an issue with setting cookie paths that contain the underscore [_] and dash [-] characters on IIS6.
This issue is a known "feature" that was added to IIS6 to help prevent cross-site scripting vunerabilities (See: http://tinyurl.com/n5hq9).
Basically, when IIS6 is asked to go to a URI that doesn't contain a trailing slash, it will "courtesy redirect" to the URI with a trailing slash, but in doing so will encode underscores and dashes into their ASCII codes (%5F and %2D respectively).
Now, while this normally wouldn't be an issue, when a cookie is set by PHP using a defined path the unencoded version is used for the path. PHP does not know that the path is encoded, as IIS6 decodes it before it's given to the script (I assume).
Example:
URI = http://somedomain.com/some_directory
IIS redirects = http://somedomain.com/some%5Fdirectory/
PHP sees: http://somedomain.com/some_directory/
PHP_SELF: /some_directory/script.php
So, setting the path: path="/some_directory/"
but browser sees: path="/some%5Fdirectory/" which are not equal, so therefore the paths aren't the same and the cookie isn't retrieved.
Normally this wouldn't be an issue: simply don't specify a path & the browser handles it for you; or don't use underscores or dashes in the URI; or specify the URI with the trailing slash. But when used to lock down sessions to a specific directory (which might have those characters) this becomes a big problem (default session path is /).
The solution is to also set a cookie using the session information (name, value & other parameters) for the encoded version of the path, then the same session will be used for either version of the path.
Cameron.
simon at go4 dot com dot au
26-Feb-2006 03:26
For some reason setting a cookie path without a domain does not appear to work, eg.
<?php
setcookie('cookieName', 'cookieValue', time()+3600, '/');
?>
The path remains the default; 'The default value is the current directory that the cookie is being set in'. So you cannot access the cookie from outside that sub-directory.
However if you set the cookie with a blank domain, eg.
<?php
setcookie('cookieName', 'cookieValue', time()+3600, '/', false);
?>
Then the path override will work and you can access it from any path in the domain using the code in the above example ('/').
NOTE: setting the domain to false will cause it to be filled with the default value.
r dot namakshenas at gmail dot com
06-Feb-2006 12:38
if you are using Dreamweaver 8 and the file encoding is set to UTF and BOM has been selected to define Byte Order, a disturbing "\377" is added to the start of the page which causes failure for cookies, sessions and headers and is not displayed in Dreamweaver. You will need to edit the file again using vi or similar editors and delete "\377". It took me several working hours.
simplifiedwebsystems
26-Jan-2006 10:36
I needed to access COOKIE data before the next page load, so here's the solution:
Accessing PHP $_COOKIE value before new page load or page refresh:
<?PHP
setcookie('key', 'value', time()+60*60*24*30);
if (!isset($_COOKIE['key'])) {
$_COOKIE['key'] = 'value';
}
?>
useradd at hotmail dot com
13-Dec-2005 05:55
ok, I want to contribute with a simply calculator that uses cookies for saving the results... Sure you'll find so basic.
<?php
include("xmlvalido.php");
if(isset($_COOKIE["ACUMULADO"])&&(!isset($_POST["CE"]))){
$valor = $_COOKIE["ACUMULADO"];
if($_POST["op"]=="1"){
$valor_nuevo=$valor+$_POST["dat"];
}
if($_POST["op"]=="2"){
$valor_nuevo=$valor-$_POST["dat"];
}
if($_POST["op"]=="3"){
$valor_nuevo=$valor*$_POST["dat"];
}
if($_POST["op"]=="4"){
$valor_nuevo=$valor/$_POST["dat"];
}
setcookie("ACUMULADO",$valor_nuevo);
echo abre_web("Mi calculadora");
}else{
setcookie("ACUMULADO",0);
$valor_nuevo=0;
$valor=0;
echo abre_web("Mi calculadora");
}
?>
<br/>
<p> Valor calculado hasta ahora: <?php
echo $valor_nuevo;?></p>
<form action="calculadora.php" method="POST">
<p><input type="radio" name="op" value="1">Sumar</p>
<p><input type="radio" name="op" value="2">Restar</p>
<p><input type="radio" name="op" value="3">Multiplicar</p>
<p><input type="radio" name="op" value="4">Dividir</p>
<p>Valor: <input type="text" name="dat"></p>
<input type="submit" value="Calcular" name="Calcular">
<input type="submit" value="CE" name="CE">
</form><?php
echo cierra_web();
?>
Note I've created a file called "funciones.php" that provides my php all the headers for making valid xhtml webs! Here I'm posting it...
...xmlvalido.php
<?php
function abre_web($titulo)
{
$salida=<<<TXT
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="sp" lang="sp">
<head>
<title>$titulo</title>
</head>
<body>
<p>
TXT;
return $salida;
}
function cierra_web(){
$salida=<<<TXT
</p>
</body>
</html>
TXT;
echo $salida;
}
function enlace($texto, $url){
$salida=<<<TXT
<a href="$url">$texto</a>
TXT;
return $salida;
}
?>
no at spam dot com
10-Dec-2005 01:47
To workaround the header issue with php/IIS I opened the php.ini file and enabled the following option.
; Output buffering allows you to send header lines (including cookies) even
; after you send body content, at the price of slowing PHP's output layer a
; bit. You can enable output buffering during runtime by calling the output
; buffering functions. You can also enable output buffering for all files by
; setting this directive to On. If you wish to limit the size of the buffer
; to a certain size - you can use a maximum number of bytes instead of 'On', as
; a value for this directive (e.g., output_buffering=4096).
output_buffering = On
All cookies work fine now :)
marc at NOSPAM dot grootkoerkamp dot net
13-Oct-2005 12:59
If you want to secure your cookies with the HttpOnly attribute (only supported by IE6. see http://msdn.microsoft.com/workshop/author/dhtml/httponly_cookies.asp ) you could create your own setcookie function by using the following function:
<?php
function mgk_setcookie($sName,$sValue,$iExpire=false,
$sPath="",$sDomain="",$bSecure=false,$bHttpOnly=true) {
$sHeader = "Set-Cookie: $sName=$sValue";
if ($sPath) { $sHeader .= "; Path=$sPath";
}
if ($iExpire !==false || $iExpire !== 0 ) {
$sHeader .= "; Max-Age=$iExpire";
}
if ($sPath) { $sHeader .= "; Path=$sPath";
}
if ($sDomain) { $sHeader .= "; Domain=$sDomain";
}
if ($bSecure) { $sHeader .= "; Secure";
}
if ($bHttpOnly) { $sHeader .= "; HttpOnly";
}
$sHeader .= "; Version=\"1\""; header($sHeader);
}
?>
simon at ruderich dot com
01-Aug-2005 02:21
If you want to delete a session cookie, you can do it with this code:
<?php
session_start();
$sessionName = session_name();
$sessionCookie = session_get_cookie_params();
session_destroy();
setcookie($sessionName, false, $sessionCookie['lifetime'], $sessionCookie['path'], $sessionCookie['domain'], $sessionCookie['secure']);
?>
This works also well if the session cookie params or the session name were changed.
lharkleroad at gmail dot com
18-Jul-2005 03:12
In response to Snupha's note, one way to get the desired result on the server side, and therefore work around the user's local date and time, is to store your session information in a sessions table in your database.
For example:
1. Create a sessions table in your favorite db with a 32 char sessionid column, modifed and created datetime columns, and any other columns that you want to associate with the session such as a userid.
2. In your PHP script, create a variable containing the 32 char unique ID for your session, and store the result in a sessionid cookie that expires at the end of the browser session, and also insert it in a new row in your sessions table.
3. When your scripts check for the existance of the sessionid cookie, if a value is returned, they would check against the sessions table in your database to find the matching ID, updating the modified datetime for that record to keep the session active. If the server time elapsed since the record was modified exceeds your timeout constraints, you can force the user to reauthenticate and issue them a new session ID if desired.
4. If you require a login to some part of your site, you can also update the session record with the userid to link the session to the user.
I decided to use this method on a recent project where both PHP and ColdFusion needed to access the same datasource for different applications. The result is a language-independent session in which multiple web servers on the same domain (but potentially different sub-domains) can know when the user has logged in and allow them to continue the session on the other server. Otherwise, using the sessions built in to PHP and ColdFusion would require separate logins when switching between applications programmed in the two languages.
Going a little further with this, you can then report stats on the sessions table for the average session length by comparing the created and modified columns, or get a session history for a particular user.
I hope this helps a few people. Have fun!
p dot nowicki at hero dot mac dot edu dot pl
07-Jul-2005 09:03
It takes me some time to solve a problem with PHPSESSID propagation in URL's when --enable-trans-sid is on.
The problem was that even when user has cookies turned on, sometimes PHPSESSID has been shown in URL. I used subdomains on my page to make the URL's more user-friendly.
It turn out that the session cookie was automaticly set to main domain address with "www" (ex. "www.domain.top_domain"), when session.cookie_domain was set to (default value) "no value".
Adding
<?php
ini_set("session.cookie_domain", ".domain.top_domain");
?>
helped, and now when session cookie is set, all URL's are clear from the nasty session id.
Right now it seems to be pretty logical, but sometimes you can easly forget about something like that.
James
22-Jun-2005 10:34
"If you cannot get a cookie to stick when using an expiration date..."
Also the session.cookie_lifetime parameter in php.ini seems to cause the problem. If this value is set to zero, the cookie will always expire when you close the browser even though you specify expiration time in set_cookie(). After setting session.cookie_lifetime to some nonzero value, my cookies stuck. :)
(Apache 1.3.33, PHP 5.0.4)
nahtan at email dot com
11-Jun-2005 04:35
I tried for an hour to figure out how to have a session cookie (one that deletes when the browser is closed) with a path.
If you specify 0 as the expire parameter, the cookie will be a session cookie. eg:
setcookie("test", "value", 0, "/somepath/");
Snupha
07-Jun-2005 01:24
If you cannot get a cookie to stick when using an expiration date - check that local computer's time and time zone!
I spent hours trouble-shooting my code when I realized that the computer time on a client's computer was 7 years into the future which automatically expired the cookie before it could be used! Go figure, I'm going to look now for a work around that I can do on the server-side.
terry at scribendi dot com
08-May-2005 07:07
A few comments have suggested using serialize() to set object or array data into a cookie. There are a couple of reasons to be carefull with that technique:
Security: If the cookie is human readable, then it is also fairly easy for end users to play around with it. Wrapping your cookie setting and getting in an encryption routine will prevent tampering, and make sure that your cookies don't make any sense to any client-side exploits or other sites they get sent to thanks to browser bugs.
Bulk: If you serialize even a fairly simple class, then you get a lot of data. Large cookies will make browser requests fat and slow, and some browsers have a limit on cookie size, so think about what data you really need to persist, and create __sleep() and __wakeup() methods to package the data into the shortest possible form. You can get better and faster results when you write your own __sleep() and __wakup() to implode() or pack() your data, than by using zlib compress() on the serialized object.
support at duggen dot net
20-Apr-2005 10:21
Addition to "Carl V"s note. Thanks for the note.
Here is a way to delete alle cookies and cookie arrays from your domain.
$cookiesSet = array_keys($_COOKIE);
for ($x = 0; $x < count($cookiesSet); $x++) {
if (is_array($_COOKIE[$cookiesSet[$x]])) {
$cookiesSetA = array_keys($_COOKIE[$cookiesSet[$x]]);
for ($c = 0; $c < count($cookiesSetA); $c++) {
$aCookie = $cookiesSet[$x].'['.$cookiesSetA[$c].']';
setcookie($aCookie,"",time()-1);
}
}
setcookie($cookiesSet[$x],"",time()-1);
}
scissorjammer at hotmail dot com
08-Apr-2005 12:18
As per Sijmen Ruwhof's comment:
It's not that the domain requires a dot as much as it requires a fully qualified domain name. Setting it to false is a valid workaround, as it will default to whatever domain the page is being accessed at. If a fully qualified domain name is unavailable, consider editing your hosts file on both the client and server to have a common domain name to use for the cookie.
Carl V
07-Apr-2005 08:29
If you want to delete all the cookies set by your domain, you may run the following:
<?php
$cookiesSet = array_keys($_COOKIE);
for ($x=0;$x<count($cookiesSet);$x++) setcookie($cookiesSet[$x],"",time()-1);
?>
Very useful when doing logout scripts and the cookie name may have changed (long story).
jonathan at jonathanopie dot com
23-Mar-2005 02:00
I've found that when using header("Location: <destination page>") type 302 redirect, that cookie information in the header will be silently dropped if the <destination page> path includes any non-alphanumeric (except the allowed "-" and ".") characters. That had been pointed out above, and is documented with Microsoft as by design...
http://support.microsoft.com/default.aspx?scid=kb;EN-US;316112
...but what is not made clear, is that the rule seems to include file and directory names too!
Also, I've had unpredictable results when the <destination page> filename begins with ANY character other than strictly alphanumeric characters, even the otherwise allowed "-" and "." characters; and/or if the <destination page> is in a different directory.
Alchaemist
14-Mar-2005 03:36
setcookie + header Location + IIS 5 = Trouble
It took me a long time to figure out what was causing a missing cookie in one system while it worked perfectly in another...
See this one: http://support.microsoft.com/kb/q176113/
In short, this WILL NEVER WORK IN IIS 5:
<?php
header("Pragma: no-cache");
header('Location: http://www.example.com/');
setcookie('AA','1',0,'/');
setcookie('BB','2',time() + 24 * 3600,'/');
?>
You will ONLY get the Location Header, everything else will be "cut out" by IIS 5 CGI implementation.
Solutions:
1- Migrate to Apache/IIS6/Whatever
2- Use a Non Parsed Header Script (nph-*.php)
3- Try with header('Refresh: 0; $URL');
I hope this helps somebody not to spend hours knocking his/her head.
Alchaemist
dear_grommet at reverse dot liamtoh dot moc
04-Mar-2005 11:41
When using cookies to store PHP variables with serialize(),
I found that I also needed to use stripslashes().
Here is an example of code that does what the PHP web site
does - remembering your last search options at the top of the
page.
I would initialise my variable $cookie_data to whatever I wanted,
and I use an array, eg:
<?php
$cookie_data['hist_days'] = 15;
$cookie_data['test1'] = "a string test $ ; \" & ";
$cookie_data['test2'] = 0;
$cookie_data_expire = 60 * 60 * 24 * 60;
?>
And then this code, run at the start of the script, after the
session_start(), will store/restore this cookie data...
<?php
if (isset($_SESSION['cookie_data']))
{
$cookie_data = $_SESSION['cookie_data'];
}
else
{
if (isset($_COOKIE['cookie_data']))
{
$string = $_COOKIE['cookie_data'];
$string = stripslashes($string);
$cookie_data = unserialize($string);
}
}
?>
NB. I found that for such a small amount of data, the gzcompress()
made the string bigger.
The idea is that if the $_SESSION data is available, then it takes
precedence, but if not, then it will re-load the last values from a
cookie that was stored (for the last 60 days).
Then you need to get any user changes for any values and copy
them back into the $_SESSION data.
Then set both the $_SESSION and cookie data., eg:
<?php
$cookie_data['test2']++;
$_SESSION['cookie_data'] = $cookie_data;
$string = serialize($cookie_data);
setcookie('cookie_data', $string, time()+$cookie_data_expire, '/');
$_SESSION['cookie_data'] = $cookie_data;
?>
Danny Lin
19-Feb-2005 08:37
I have XP Home and IE6. I tried the example 3:
<?php
setcookie("cookie[three]", "cookiethree");
setcookie("cookie[two]", "cookietwo");
setcookie("cookie[one]", "cookieone");
if (isset($_COOKIE['cookie'])) {
foreach ($_COOKIE['cookie'] as $name => $value) {
echo "$name : $value <br />\n";
}
}
?>
And it worked. However, when I added expiration info, it stopped working. Then, I noticed that it might be related to the time() on my server (hosted in Texas). With the debugging code below, I found out I have to add two hours. (You will need to "fresh" the browser to get the cookies set.)
<?
for ($i = 0; $i < 10; $i++) {
$time[$i] = time();
setcookie("time_report[$i]",$time[$i], $time[$i]+3600*$i);
}
print_r($_COOKIE);
?>
sikon at gorodok dot net
09-Feb-2005 07:13
The documentation says, 'Consider explode() or serialize() to set one cookie with multiple names and values'. It means implode(), of course, since it is implode() that constructs a string from an array, and explode() splits a string into an array.
Jos Enrique Serrano Expsito
04-Feb-2005 12:36
For listing all the cookies readed in the client machine.- echo sHTTP_COOKIE_VARS();
<?php
function sHTTP_COOKIE_VARS() {
global $HTTP_COOKIE_VARS; $sEcho = '';
$iCookies = 0;
ForEach( $HTTP_COOKIE_VARS As $vIndex => $vValue ) {
$iCookies++;
if( is_array( $vValue ) ) {
foreach ( $vValue as $vIndex2 => $vValue2 ) {
$sEcho .= '$HTTP_COOKIE_VARS[\'<b>'.$vIndex."</b>']['".$vIndex2.'\'] == "'.
$vValue2.'"<br>';
}
} else {
$sEcho .= '$HTTP_COOKIE_VARS[\'<b>'.$vIndex.'</b>\'] == "'.
$vValue.'"<br>';
}
}
$sEcho .= $iCookies.' cookies listed.';
return $sEcho; }
?>
do not spam M. Kristall at MKP
24-Jan-2005 10:18
The "bug" that prevents cookies from working properly with Windows XP and Internet Explorer 6 seems to be a more strict following of the cookie specifications. This part in particular:
Only hosts within the specified domain can set a cookie for a domain and domains must have at least two (2) or three (3) periods in them to prevent domains of the form: ".com", ".edu", and "va.us". Any domain that fails [sic] within one of the seven special top level domains listed below only require two periods. Any other domain requires at least three. The seven special top level domains are: "COM", "EDU", "NET", "ORG", "GOV", "MIL", and "INT".
localhost should not work. Neither should localhost.localdomain. Though, it may be a bug that 127.0.0.1 does not work, even despit the fact that 127.0.0.1 is not a domain name.
glillibridge at yahoo dot com
08-Jan-2005 11:27
mleer at sp dot nl 19-Dec-2002 02:50 had a very similar problem to my own.
My page is being called from a client url as part of a 100% frame so the url would look correct to the user (reason: PR). My cookies stopped working.
mleer suggested sending the following header:
header('P3P: CP="NOI ADM DEV PSAi COM NAV OUR OTRo STP IND DEM"');
Unfortunately it did not work for me. I found the below header command at http://www.sitepoint.com/article/p3p-cookies-ie6/2
It worked for me.
header('P3P: CP="IDC DSP COR CURa ADMa OUR IND PHY ONL COM STA"');
Good luck.
Sijmen Ruwhof
02-Jan-2005 12:41
My experience with setting cookies, a must read for every developer that doenst want to spend his time debugging cookies..
- if your're using windows XP with Internet Explorer, having a local webserver running and you're setting a cookie in you script, don't set the domain name! Use false instead. Windows XP in combination with Internet Explorer (with Firefox your cookie will be set successful) will not set a cookie when the domain name points to localhost. Examples:
<?
setcookie('test', 'value', false, '/', 'localhost', 0); ?>
Someone noted already this bug in WinXP + IE, but said that the domainname should have a dot in it. That is totally untrue (i've tried a domainname with a dot in it that points to 127.0.0.1). I think that the problem persist that the domainname may not be pointing to 127.0.0.1 so the solution would be:
<?php
setcookie('test', 'value', false, '/', false, 0); ?>
- be sure that the 4th argument (path) always ends with a slash '/'
- be sure that the expire time is false or a timestamp, 0 is not the value for a session cookie (false is the value).
-- Sijmen Ruwhof
adam at metrovanlines dot com
23-Mar-2004 03:47
This limitation is mentiones in the <a href=http://wp.netscape.com/newsref/std/cookie_spec.html> Netscape HTTP Cookies Preliminary Specification </a> above but I thought it might save someone some time if it was posted here. (I wasted almost a day about it, Serves me right for not RTFMing ...)
There are limitations on the number of cookies that a client can store at any one time. This is a specification of the minimum number of cookies that a client should be prepared to receive and store.
* 300 total cookies
* 4 kilobytes per cookie, where the name and the OPAQUE_STRING combine to form the 4 kilobyte limit.
* 20 cookies per server or domain. (note that completely specified hosts and domains are treated as separate entities and have a 20 cookie limitation for each, not combined)
Servers should not expect clients to be able to exceed these limits. When the 300 cookie limit or the 20 cookie per server limit is exceeded, clients should delete the least recently used cookie. When a cookie larger than 4 kilobytes is encountered the cookie should be trimmed to fit, but the name should remain intact as long as it is less than 4 kilobytes.
apex at xepa dot nl
24-Nov-2003 06:59
[Editor's note: ... or simply use sessions. You can't be sure that the visitor will use the same IP the next visit. Not even on the next request (thanks to proxy servers)]
Note on setting cookies allowing access to sites:
If you are not using something "personal" from the computer that you are sending the cookie too watch out. Via javascript it is possible to steal cookies from other users. Thus allowing the stealer to login to your site as another user that might not have access otherwise. Try to add something like the user's ip in the cookie and allowing access from that ip only with the stored cookie data.
Jrg Aldinger
30-Sep-2003 04:13
When using your cookies on a webserver that is not on the standard port 80, you should NOT include the :[port] in the "Cookie domain" parameter, since this would not be recognized correctly.
I had the issue working on a project that runs on multiple servers (development, production, etc.). One of the servers is running on a different port (together with other websites that run on the same server but on different ports).
dave at fubra dot com
09-Sep-2003 12:36
There are several characters that dont work correctly if part of the cookie name, I in particular ran into problems using = as part of the cookie name ie/
setcookie('dE4fR=', $foo);
this was as a result of base64_encode() ing a variable to use as the name. The cookie was being set fine but the = is stored as a little square character in the cookie which prevent proper retreival.
The solution for me was to use md5() instead of base64_encode() but any other method which avoids the = sign should also solve the problem
thomas at proton dot mine dot nu
29-Jun-2003 04:07
Browsers like Opera and Mozilla are told to need the full page loaded to accept cookies (that's what bmatzelle at NOSPAM dot yahoo dot com said).
You can use cookies at reloading pages, however after sending out all headers call exit(); to stop the rest of the script, so the actual page content is not sent out.
soreman at abv dot bg
11-Apr-2003 03:26
If you experience problems on Microsoft Information Server (IIS) when setting a cookie via PHP and when PHP is running as a CGI binary it is not setting the cookie. After spending many hours on what the problem is here is what happens:
When you invoke setcookie and redirect to another page you will not have your cookie set, because it seems that IIS doesn't set the cookie unless you actually send some contents to the browser. Therefore if you want to set a cookie and then redirect to another page you will have to do the redirection via JavaScript and/or HTML if you want your script to work on IIS.
neil
20-Jan-2003 12:34
Some versions of IE6, when you drop a non-persistent cookie, handle this incorrectly and instead drop a persistent cookie.
This is not PHP's fault: ) Rather it is a bug in these versions of IE6. I am posting this because people may be programming session IDs and tokens in what they believe to be non-persistent cookies. Specifically, IE6 build 6.0.2800.1106CO (SP1) does this.
IE6, in this case, will make your application insecure. You should notify IE6 users to manually delete their cookies after their session is completed. Will they do this, no. At least you did your part to notify them of the risk.
We found this to be true after an ethical hack which condemned the use of SessionID's in query string, even if the entire session begins, happens, and ends, in https. M$ Proxy Server (here we go with M$ crappy security) writes these session ID's to it's proxy logs. Since Proxy Server is easily comprimised with numerous well known hacks, your sessions can be. I have seen the logs and seen the sessionid's in https.
Unfortunately, these EH fellows are forgetting that most user's systems are less secure and less patched than most ISP's and corporate proxy servers. We are simply moving the vulnerability to the client by using cookies. If it were up to me, I would leave sessionid in query string.
I was proven right in the case with this browser.
thx
Neil
mleer at sp dot nl
19-Dec-2002 02:50
P3P is a good idea. But.
IE 6 features an inadequate definition of third party cookies.
If your site is hosted on server A and your PHP stuff is coming in a framesetting from server B your setcookie-attempts will be blocked when default privacy settings are deployed. Your secondparty-cookie will be regarded as a thirdparty-cookie.
So what you do is not read the P3P-Internet Explorer 6-manual at MS but send a header like
header('P3P: CP="NOI ADM DEV PSAi COM NAV OUR OTRo STP IND DEM"');
before doing the setcookie-thing. This will enable your cookie to survive any IE-6 privacy settings.
You won't do this if you're working for some doubleclick institution, because if you do, you... you...well... you are not a very nice person!
robert at ourwebhome dot com
05-Dec-2001 03:41
Internet Exploer 6 now requires sites that set cookies to have P3P policies.
From the Microsoft page:
"Internet Explorer 6 implements advanced cookie filtering that is based on the Platform for Privacy Preferences (P3P) specification. By default, Internet Explorer 6 blocks third-party cookies that do not have a compact policy (a condensed computer-readable privacy statement) or third-party cookies that have a compact policy which specifies that personally identifiable information is used without your implicit consent. First-party cookies that have a compact policy which specifies that personally identifiable information is used without implicit consent are downgraded (deleted when you close Internet Explorer). First-party cookies that do not have a compact policy are leashed (restricted so that they can only be read in the first-party context)."
See:
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q260971&GSSNB=1
For more about P3P:
http://www.w3.org/P3P/
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