Sessions or Cookies?

[demonicfoetus]

Hi there

I have a few questions about sessisons and cookies...

$fp = fopen("$DOCUMENT_ROOT/$user.txt","r");
$userdata = fgetcsv($fp,100, "\n");
if ($user == $userdata[0] && $pass == $userdata[1])
   {
	session_register("username");
                 $HTTP_SESSION_VARS["username"] = $user;
  }	

With this code will it mean that each time a user logs in, they will be given a unique 'username' session OR will it simply overwrite the variable everytime someone else logs in?

If i did this with cookies, would it also overwrite it or would it be as the cookie is stored on their computer it would not overwrite they would have a unique one. So meaning that HTTP_COOKIE_VARS[username] is actually extracted from their computer?

Thanks

-DF

[planetsim]

No and Yes(kinda)
Basically sessions last a certain amount of time just like Cookies.

Once the browser is closed the sessions is killed and should be fully deleted by the server within 5mins or so. Sessions can be registered as the same name over and over again.

Now Cookies, expire just like Sessions do.
Except the difference is you get the choice on how long they go for, (You can do this with sessions either with session_cache() or using the php.ini) now if the time is up the cookie is dead however the cookie can still exist so you must check to see if its set. Empty can work but isset() is best for cookies.