goldvision.com - PHP / setcookie

Description

int setcookie ( string name [, string value [, int expire [, string path [, string domain [, int secure]]]]])

setcookie() defines a cookie to be sent along with the rest of the header information. Cookies must be sent before any other headers are sent (this is a restriction of cookies, not PHP). This requires you to place calls to this function before any <html> or <head> tags.

All the arguments except the name argument are optional. If only the name argument is present, the cookie by that name will be deleted from the remote client. You may also replace any argument with an empty string ("") in order to skip that argument. The expire and secure arguments are integers and cannot be skipped with an empty string. Use a zero (0) instead. The expire argument is a regular Unix time integer as returned by the time() or mktime() functions. The secure indicates that the cookie should only be transmitted over a secure HTTPS connection.

Common Pitfalls:

Cookies will not become visible until the next loading of a page that the cookie should be visible for.
Cookies must be deleted with the same parameters as they were set with.

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. In PHP 4, multiple calls to setcookie() are performed in the order called.

Some examples follow how to send cookies:
Example 1. setcookie() send examples
setcookie ("TestCookie", $value); setcookie ("TestCookie", $value,time()+3600); /* expire in 1 hour */ setcookie ("TestCookie", $value,time()+3600, "/~rasmus/", ".utoronto.ca", 1);

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:
Example 2. setcookie() delete examples
// set the expiration date to one hour ago setcookie ("TestCookie", "", time() - 3600); setcookie ("TestCookie", "", time() - 3600, "/~rasmus/", ".utoronto.ca", 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. To see the contents of our test cookie in a script, simply use one of the following examples:

echo $TestCookie;
echo $HTTP_COOKIE_VARS["TestCookie"];

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:

setcookie ("cookie[three]", "cookiethree");
setcookie ("cookie[two]", "cookietwo");
setcookie ("cookie[one]", "cookieone");
if (isset ($cookie)) {
    while (list ($name, $value) = each ($cookie)) {
        echo "$name == $value<br>\n";
    }
}

For more information on cookies, see Netscape's cookie specification at http://www.netscape.com/newsref/std/cookie_spec.html.

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.