setcookie
(PHP 4, PHP 5)
setcookie — Send a cookie
Описание
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.
Once the cookies have been set, they can be accessed on the next page load with the $_COOKIE or $HTTP_COOKIE_VARS arrays. Note, superglobals such as $_COOKIE became available in PHP 4.1.0. Cookie values also exist in $_REQUEST.
Список параметров
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.
See » Netscape cookie specification for specifics on how each setcookie() parameter works
- name
-
The name of the cookie.
- 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 set to 0, or omitted, the cookie will expire at the end of the session (when the browser closes).
Замечание: 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.
- 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 from the client. When set to TRUE, the cookie will only be set if a secure connection exists. The default is FALSE. On the server-side, it's on the programmer to send this kind of cookie only on secure connection (e.g. with respect to $_SERVER["HTTPS"]).
- httponly
-
When TRUE the cookie will be made accessible only through the HTTP protocol. This means that the cookie won't be accessible by scripting languages, such as JavaScript. This setting can effectly help to reduce identity theft through XSS attacks (although it is not supported by all browsers). Added in PHP 5.2.0. TRUE or FALSE
Возвращаемые значения
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.
Примеры
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); /* expire in 1 hour */
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:
<?php
// Print an individual cookie
echo $_COOKIE["TestCookie"];
echo $HTTP_COOKIE_VARS["TestCookie"];
// Another way to debug/test is to view all cookies
print_r($_COOKIE);
?>
Пример #2 setcookie() delete example
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:
<?php
// set the expiration date to one hour ago
setcookie ("TestCookie", "", time() - 3600);
setcookie ("TestCookie", "", time() - 3600, "/~rasmus/", ".example.com", 1);
?>
Пример #3 setcookie() and arrays
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:
<?php
// set the cookies
setcookie("cookie[three]", "cookiethree");
setcookie("cookie[two]", "cookietwo");
setcookie("cookie[one]", "cookieone");
// after the page reloads, print them out
if (isset($_COOKIE['cookie'])) {
foreach ($_COOKIE['cookie'] as $name => $value) {
echo "$name : $value <br />\n";
}
}
?>
Результат выполнения данного примера:
three : cookiethree two : cookietwo one : cookieone
Примечания
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.
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.
Multiple calls to setcookie() are performed in the order called.
- checkdnsrr
- closelog
- define_syslog_variables
- dns_check_record
- dns_get_mx
- dns_get_record
- fsockopen
- gethostbyaddr
- gethostbyname
- gethostbynamel
- gethostname
- getmxrr
- getprotobyname
- getprotobynumber
- getservbyname
- getservbyport
- header_register_callback
- header_remove
- header
- headers_list
- headers_sent
- http_response_code
- inet_ntop
- inet_pton
- ip2long
- long2ip
- openlog
- pfsockopen
- setcookie
- setrawcookie
- socket_get_status
- socket_set_blocking
- socket_set_timeout
- syslog
Коментарии
Note when setting "array cookies" that a separate cookie is set for each element of the array.
On high traffic sites, this can substantially increase the size of subsequent HTTP requests from clients (including requests for static content on the same domain).
More importantly though, the cookie specification says that browsers need only accept 20 cookies per domain. This limit is increased to 50 by Firefox, and to 30 by Opera, but IE6 and IE7 enforce the limit of 20 cookie per domain. Any cookies beyond this limit will either knock out an older cookie or be ignored/rejected by the browser.
something that wasn't made clear to me here and totally confused me for a while was that domain names must contain at least two dots (.), hence 'localhost' is invalid and the browser will refuse to set the cookie! instead for localhost you should use false.
to make your code work on both localhost and a proper domain, you can do this:
<?php
$domain = ($_SERVER['HTTP_HOST'] != 'localhost') ? $_SERVER['HTTP_HOST'] : false;
setcookie('cookiename', 'data', time()+60*60*24*365, '/', $domain, false);
?>
If you want to delete all cookies on your domain, you may want to use the value of:
<?php $_SERVER['HTTP_COOKIE'] ?>
rather than:
<?php $_COOKIE ?>
to dertermine the cookie names.
If cookie names are in Array notation, eg: user[username]
Then PHP will automatically create a corresponding array in $_COOKIE. Instead use $_SERVER['HTTP_COOKIE'] as it mirrors the actual HTTP Request header.
<?php
// unset cookies
if (isset($_SERVER['HTTP_COOKIE'])) {
$cookies = explode(';', $_SERVER['HTTP_COOKIE']);
foreach($cookies as $cookie) {
$parts = explode('=', $cookie);
$name = trim($parts[0]);
setcookie($name, '', time()-1000);
setcookie($name, '', time()-1000, '/');
}
}
?>
Note that the $_COOKIE variable not will hold multiple cookies with the same name. It is legitimate to set two cookies with the same name to the same host where the sub domain is different.
<?php
setcookie("testcookie", "value1hostonly", time(), "/", ".example.com", 0, true);
setcookie("testcookie", "value2subdom", time(), "/", "subdom.example.com", 0, true);
?>
The next request from the browser will have both cookies in the $_SERVER['HTTP_COOKIE'] variable, but only one of them will be found in the $_COOKIE variable. Requests to subdom.example.com will have both cookies, while browser request to example.com or www.example.com only sends the cookie with the "value1hostonly" value.
<?php
$kaker = explode(";", $_SERVER['HTTP_COOKIE']);
foreach($kaker as $val){
$k = explode("=", $val);
echo trim($k[0]) . " => " . $k[1];
}
// output
testcookie => value1hostonly
testcookie => value2subdom
?>
A period in a cookie name (like user.name) seems to show up in the $_COOKIE array as an underscore (so user_name). This means that for example $_COOKIE["user_name"] must be used to read a cookie that has been set with setcookie("user.name" ...), which is already rather confusing.
Furthermore the variable $_COOKIE["user_name"] will retain the value set by setcookie("user.name" ...) and no amount of calling setcookie("user_name" ...) will alter this value. This is rather trivially fixed by clearing the "user.name" cookie, but it can take a while to realize this since there's only "user_name" in $_COOKIE.
Hope this saves someone some time.
Want to remove a cookie?
Many people do it the complicated way:
setcookie('name', 'content', time()-3600);
But why do you make it so complicated and risk it not working, when the client's time is wrong? Why fiddle around with time();
Here's the easiest way to unset a cookie:
setcookie('name', 'content', 1);
Thats it.
Instead of this:
<?php setcookie( "TestCookie", $value, time()+(60*60*24*30) ); ?>
You can this:
<?php setcookie( "TestCookie", $value, strtotime( '+30 days' ) ); ?>
Caveat: if you use URL RewriteRules to get stuff like this: domain.com/bla/stuf/etc into parameters, you might run into a hickup when setting cookies.At least in my setup a change in one of the parameters resulted in the cookie not being 'there' anymore.
The fix is simple: specify the domain. '/' will usualy do fine.
It's worth a mention: you should avoid dots on cookie names.
<?php
// this will actually set 'ace_fontSize' name:
setcookie( 'ace.fontSize', 18 );
?>
The " PHPSESSID " cookie will soon be rejected because its " sameSite " attribute is set to " none " or an invalid value, and without " secure " attribute. To learn more about the "sameSite" attribute, visit https://developer.mozilla.org/docs/Web/HTTP/Headers/Set-Cookie/SameSite.
<?php
ini_set("session.cookie_secure", 1);
session_start();
my PHP code ....
?>
Just an example to clarify the use of the array options, especially since Mozilla is going to deprecate / penalise the use of SameSite = none, which is used by default if not using array options.
<?php
$arr_cookie_options = array (
'expires' => time() + 60*60*24*30,
'path' => '/',
'domain' => '.example.com', // leading dot for compatibility or use subdomain
'secure' => true, // or false
'httponly' => true, // or false
'samesite' => 'None' // None || Lax || Strict
);
setcookie('TestCookie', 'The Cookie Value', $arr_cookie_options);
?>
In any web browser there is a very commonly used option "Open previous windows and tabs" which is disabled by default, but many people enable it.When this option is active, the web browser, when closing and reopening, instead of executing the termination and starting a new session, saves and restores the current session along with session cookies and sessionStorage.
Both session cookies and sessionStorage, contrary to expectations, can live for a very long time until the user closes the tab before closing the web browser.
If you want a cookie, for example with a time offset, to be guaranteed to have a short lifetime, you should explicitly specify this short lifetime, rather than relying on self-deletion on the session cookie.