NYCPHP Meetup

[Flavio daCosta]

On 06/29/2005 02:18 AM, Daniel Krook wrote:
> So, to pose a new question on the value of learning about bitwise 
> operators, what would you use them for in a standard web application?  ACL 
> determination?  What else?

I utilize bit functions for flag handling and simple ACL in the same
fashion as the built error reporting
<http://www.php.net/manual/en/function.error-reporting.php>

for example:
define( 'D_VIEW_FORTUNE',     ( 1 << 0 ) ); // 00000001
define( 'D_VIEW_LAST_LOGIN',  ( 1 << 1 ) ); // 00000010
define( 'D_VIEW_LOGIN_COUNT', ( 1 << 2 ) ); // 00000100
...
// Normally dynamically set for each user
$display_view = D_VIEW_FORTUNE | D_VIEW_LOGIN_COUNT; // 00000101
...
if( $display_view & D_VIEW_FORTUNE )
{
    // display fortune
}
...

I will also use them as an efficient way to detect every other row ;)

    $i = 0;
    while( ... )
    {
        if( ++$i&1 ) // Row is odd;
    }



Flavio