|
|
Posted by Tom Thackrey on 07/08/05 21:01
On 8-Jul-2005, "Michael B. Trausch" <fdZEROman+spam@gmail.nospam.com>
wrote:
> I have a question regarding bitwise operators, I've been trying to
> figure this out for about two days now, and I just can't seem to get it.
> What I'm trying to do is use a variable to hold a bitmask of 'flags'
> for users on a website. The function below is supposed to be a search
> function for one of those flags in a particular thing.
>
> The idea is that when something calls userId(), it should get to see
> what type of user flags that are supported. Now I've moved things
> around, and it seems like the only if that ever executes is the first
> one, the code doesn't ever reach any of the elseif blocks.
>
> I want the function to search for the first user that it finds has a bit
> set in the bitmask and return the userId as supplied by the cookie that
> represents that bitmask.
>
> Optionally, userId() can be called with one of the arguments specifying
> a particular usertype to look for that particular usertype. The user
> can be logged into multiple sections of the site at a time, so if
> they're entering something where they need the USER_ADMIN privilege, I
> should be able to call userId(USER_ADMIN) and get their UID if they're
> an admin and E_NOT_LOGGED_IN if they're not logged in as an admin. Same
> goes for any of the options that are defined. Can anyone else see what
> is wrong with this?
>
> Thanks for the help in advance.
>
>
> Constants defined for USER_*:
> =============================
>
> define('USER_NOBODY', 0x00000000);
> define('USER_SEEKER', 0x00000001);
> define('USER_MEMPL', 0x00000002);
> define('USER_SEMPL', 0x00000004);
> define('USER_ADMIN', 0x00000008);
> define('USER_ANYBODY', 0xffffffff);
>
> Code that isn't working:
> ========================
>
> function userId($pref = USER_ANYBODY)
> {
> /*
> * If the user is logged in, this will return their user ID.
> * If they are not, then it won't. If more then one user is
> * logged in, this function will prefer MEMPL and SEMPL types
> * over any other, unless specified by $pref.
> */
>
> $uT = userType();
>
> if(userAccess($uT, $pref))
> {
> /*
> * The usertype that we're looking for is logged in.
> */
>
> if(($pref & USER_SEEKER) > 0)
> {
> $tmpCookie = $_COOKIE['seeker'];
> list($id, $i, $i, $i, $i, $i, $i) = explode(':', $tmpCookie);
>
> return($id);
> }
>
> elseif(($pref & USER_MEMPL) > 0)
> {
> $tmpCookie = $_COOKIE['mEmpl'];
> list($id, $i, $i, $i, $i, $i, $i) = explode(':', $tmpCookie);
>
> return($id);
> }
>
> elseif(($pref & USER_SEMPL) > 0)
> {
> $tmpCookie = $_COOKIE['sEmpl'];
> list($id, $i, $i, $i, $i, $i, $i) = explode(':', $tmpCookie);
>
> return($id);
> }
>
> elseif(($pref & USER_ADMIN) > 0)
> {
> $tmpCookie = $_COOKIE['admin'];
> list($id, $i, $i, $i, $i, $i, $i) = explode(':', $tmpCookie);
>
> return($id);
> }
> }
>
> // Oops. We don't have anything to do, return E_NOT_LOGGED_IN.
>
> return(E_NOT_LOGGED_IN);
> }
The problem is you aren't using the bitwise operators. & is not bitwise, &&
is
Also, you don't need the >0, if ($pref && USER_ADMIN) will work just fine
and won't have a problem if you use the high order bit as a flag.
--
Tom Thackrey
www.creative-light.com
tom (at) creative (dash) light (dot) com
do NOT send email to jamesbutler@willglen.net (it's reserved for spammers)
Navigation:
[Reply to this message]
|