Deleting Cookies

[Pi_Mastuh]

I've got a code that creates cookies to keep a user logged in, but how do I delete them for if they want to logout? If the cookie is found it re-directs to another page and I tried setting new cookies to expire an hour ago but it's not deleting the old one, which keeps the user from logging out. Here's my code:

[code] <?php
if(isset($_COOKIE['preuserID']) && isset($_COOKIE['preuserName'])){
      $_SESSION['preuserID'] = $_COOKIE['preuserID'];
      $_SESSION['preuserName'] = $_COOKIE['preuserName'];
  header("Location: ../reg/home.php");
  }[/code]

[marcus]

[code=php:0]
unset($_COOKIE['value']);

//or give it a bad value

$_COOKIE['value'] = false;
[/code]

[Pi_Mastuh]

so it would be

unset($_COOKIE['preuserID']);

unset($_COOKIE['preuserName']);

?

[marcus]

Yep, it'll destroy the cookie.

http://us3.php.net/manual/en/function.unset.php

[Pi_Mastuh]

it's not working.  :-\

[marcus]

Worked for me.

[Pi_Mastuh]

Did I do something wrong? I put it on the logout page. The logout page re-directs to the main index.php page, which re-directs to home.php IF it finds the cookies. I hit logout and it's just going to home.php, but it shouldn't be finding the cookies.

[Pi_Mastuh]

Here's all of my code

[code]<?php
//Create the cookie after the user logs in
setcookie("preuserID", $_SESSION['preuserID'], time()+60*60*24*100, "/");
      setcookie("preuserName", $_SESSION['preuserName'], time()+60*60*24*100, "/");
  header("Location: ../home.php");[/code]

[code]<?php
  // Check if user has been remembered and re-direct
  if(isset($_COOKIE['preuserID']) && isset($_COOKIE['preuserName'])){
      $_SESSION['preuserID'] = $_COOKIE['preuserID'];
      $_SESSION['preuserName'] = $_COOKIE['preuserName'];
  header("Location: ../reg/home.php");
  }[/code]

[code]<?php
//Log the user out
unset($_COOKIE['preuserID']);

unset($_COOKIE['preuserName']);[/code]

[Jessica]

Check out example 2 on the setcookie page.
http://us2.php.net/setcookie

It goes over how to delete cookies.

[Pi_Mastuh]

I tried that, it wasn't working either.

[Jessica]

Are you using Firefox? Open Tools, Options, Privacy. Click show cookies and find your cookies. See what they're set to. Then try your logout and see again.

Setting them to nothing and with an expiration date in the past should work. Why do you say it's not working?

[Pi_Mastuh]

I'm using IE. And i don't know why it wasn't working, it's still re-directing and it only does that if the cookies are found.

[printf]

You can't unset a $_COOKIE with unset();, it will only remove the scope of the local GLOBAL variable, not remove it from the browser instance!

Also don't use setcookie() if your redirecting, because not all browsers will set the cookie, if a redirect is issued in the same header! Use header(Set-Cookie:...) to set a cookie when redirecting, it's 100% cross browser safe, which setcookie() is not!


printf

[Jessica]

So, take a look in Firefox, to help ;)

[Pi_Mastuh]

[quote author=printf link=topic=123447.msg510246#msg510246 date=1169435565]
You can't unset a $_COOKIE with unset();, it will only remove the scope of the local GLOBAL variable, not remove it from the browser instance!

Also don't use setcookie() if your redirecting, because not all browsers will set the cookie, if a redirect is issued in the same header! Use header(Set-Cookie:...) to set a cookie when redirecting, it's 100% cross browser safe, which setcookie() is not!


printf
[/quote]

How do I do that?

[Pi_Mastuh]

Like this?

header(setcookie ("preuserID", "", time() - 60*60*24*100)
(setcookie ("preuserName", "", time() - 60*60*24*100)
("Location: ../")));

[printf]

You can do that way, but I most times create a function based control so I can delete all cookies at once, or set a cookie using header instead of setcookie() that doesn't work 100% across all browsers.

example...

[code]<?php

function cookie_remove ()
{
if ( ! empty ( $_COOKIE ) )
{
foreach ( $_COOKIE AS $k => $v )
{
set_cookie ( $k );
}
}
}


function set_cookie ( $name, $value = '', $expire = ( time ( ) - 86400 ), $path = '/', $domain = $_SERVER['SERVER_NAME'], $secure = false )
{
header ( 'Set-Cookie: ' . $name . '=' . $value . '; expires=' . ( $expire == 0 ? 0 : gmdate ( 'D, d-M-Y H:i:s \G\M\T', $expire ) ) . '; path=' . $path . '; domain=' . $domain . ( $secure ? '; secure;' : '' ), false );
}

?>[/code]


Then to use the functions!

[code]<?php

// removes all cookies!

cookie_remove ();

// set a cookie to last for this browser session

set_cookie ( 'auth', 'true', 0 );

// set a persistent cookie to last for a year

set_cookie ( 'auth', 'true', ( time () + 31536000 ) );

// set a persistent cookie to last for a year, valued for a certain path only

set_cookie ( 'auth', 'true', ( time () + 31536000 ), '/admin/' );

// remove a single cookie

set_cookie ( 'cookie_name_to_remove' );

?>[/code]


printf

[Pi_Mastuh]

I put it in the page and got

Parse error: parse error, unexpected '(' in /homepages/20/d175171605/htdocs/reg/logout.php on line 19

Did I do it right?

[code]function cookie_remove ()
{
if ( ! empty ( $_COOKIE ) )
{
foreach ( $_COOKIE AS $k => $v )
{
set_cookie ( $k );
}
}
}


function set_cookie ( $name, $value = '', $expire = ( time ( ) - 86400 ), $path = '/', $domain = $_SERVER['SERVER_NAME'], $secure = false )
{
header ( 'Set-Cookie: ' . $name . '=' . $value . '; expires=' . ( $expire == 0 ? 0 : gmdate ( 'D, d-M-Y H:i:s \G\M\T', $expire ) ) . '; path=' . $path . '; domain=' . $domain . ( $secure ? '; secure;' : '' ), false );
}

set_cookie ( 'preuserID' );
set_cookie ( 'preuserName' );[/code]

[printf]

Sorry about that.... (the complete working script would be something like so)

[code]<?

define ( 'COOKIE_PATH', '/' );
define ( 'COOKIE_EXPIRE', time () - 86400 );
define ( 'COOKIE_SECURE', false );

// for for global domain access use .your_domain.com, instead of $_SERVER['SERVER_NAME']

define ( 'COOKIE_DOMAIN', $_SERVER['SERVER_NAME'] );


function cookie_remove ()
{
if ( ! empty ( $_COOKIE ) )
{
foreach ( $_COOKIE AS $k => $v )
{
set_cookie ( $k );
}
}
}


function set_cookie ( $name, $value = '', $expire = COOKIE_EXPIRE, $path = COOKIE_PATH, $domain = COOKIE_DOMAIN, $secure = COOKIE_SECURE )
{
header ( 'Set-Cookie: ' . $name . '=' . $value . '; expires=' . ( $expire == 0 ? 0 : gmdate ( 'D, d-M-Y H:i:s \G\M\T', $expire ) ) . '; path=' . $path . '; domain=' . $domain . ( $secure ? '; secure;' : '' ), false );
}

set_cookie ( 'preuserID' );
set_cookie ( 'preuserName' );

?>[/code]


printf

[Pi_Mastuh]

It's just re-directing back to home.php again, which means the cookies aren't being deleted ???

[Jessica]

Are you sure there isn't more in your script?

[Pi_Mastuh]

My entire script, including all the stuff that was there before is

[code]<?php

session_start();

include("secure/config.php");

  session_unregister('preuserName');

  session_unregister('preuserID');

session_unregister('image');

session_destroy();

define ( 'COOKIE_PATH', '/' );
define ( 'COOKIE_EXPIRE', time () - 86400 );
define ( 'COOKIE_SECURE', false );

// for for global domain access use .your_domain.com, instead of $_SERVER['SERVER_NAME']

define ( 'COOKIE_DOMAIN', $_SERVER['SERVER_NAME'] );


function cookie_remove ()
{
if ( ! empty ( $_COOKIE ) )
{
foreach ( $_COOKIE AS $k => $v )
{
set_cookie ( $k );
}
}
}


function set_cookie ( $name, $value = '', $expire = COOKIE_EXPIRE, $path = COOKIE_PATH, $domain = COOKIE_DOMAIN, $secure = COOKIE_SECURE )
{
header ( 'Set-Cookie: ' . $name . '=' . $value . '; expires=' . ( $expire == 0 ? 0 : gmdate ( 'D, d-M-Y H:i:s \G\M\T', $expire ) ) . '; path=' . $path . '; domain=' . $domain . ( $secure ? '; secure;' : '' ), false );
}

set_cookie ( 'preuserID' );
set_cookie ( 'preuserName' );

header("Location: ../");
exit;

?>

[/code]