Question

This is a silly question, but I can’t seem to wrap my head around the bit mask testing associated with completing this:

Given I create a bunch of generalized functions to extend PHP’s function base:

/**
 *
 * @param string $path
 * @return array
 */
function load_array($path){
    $path = path_file($path);
    if(null === $path){
        // trigger error when appropriate
        return array();
    }
    return ((Array) require($path));
}

_{path_file() is another function in the library, just assume it to be realpath()}

What I’d like to do, is trigger errors according to the current running environment’s reporting level. Given this would be a notice, should I simply test:

if(error_reporting() <= E_USER_NOTICE){ /***/ }

That doesn’t seem right.

Answer 1

if (error_reporting() & E_USER_NOTICE) {
   ...
}

would only trigger if the E_USER_NOTICE flag has been enabled in error_reporting, using the bit-wise AND operation.

If you pretend that the error_reporting flag is only 8 bits, and the USER_NOTICE flag is at bit 4, then you’re doing:

  00001000  <--- e_user_notice
  10101111  <--- some fake error_reporting bitmask
& --------
  00001000  <-- e_user_notice is enabled. It's non-zero, so evaluates to 'true' in PHP.