(PHP 4, PHP 5)
setcookie — Send a cookie
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.
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
The name of the cookie.
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']
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).
Note: 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.
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.
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.
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"]).
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 effectively 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
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.
Some examples follow how to send cookies:
Example #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);
?>
Example #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);
?>
Example #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";
}
}
?>
上例将输出：
three : cookiethree two : cookietwo one : cookieone
| 版本 | 说明 |
|---|---|
| 5.2.0 | The httponly parameter was added. |
Note: 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.
Note: 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:
Multiple calls to setcookie() are performed in the order called.