Question

Is it possible to have PHP stop execution upon a notice/warning, globally?

We run a development server with a lot of sites on, but want to force our developers to fix these warnings/notices (or ask for help with them at least) instead of ignoring and moving on.

Answer 1

Yes, it is possible. This question speaks to the more general issue of how to handle errors in PHP. You should define and register a custom error handler using set_error_handler^docs to customize handling for PHP errors.

IMHO it’s best to throw an exception on any PHP error and use try/catch blocks to control program flow, but opinions differ on this point.

To accomplish the OP’s stated goal you might do something like:

function errHandle($errNo, $errStr, $errFile, $errLine) {
    $msg = "$errStr in $errFile on line $errLine";
    if ($errNo == E_NOTICE || $errNo == E_WARNING) {
        throw new ErrorException($msg, $errNo);
    } else {
        echo $msg;
    }
}

set_error_handler('errHandle');

The above code will throw an ErrorException any time an E_NOTICE or E_WARNING is raised, effectively terminating script output (if the exception isn’t caught). Throwing exceptions on PHP errors is best combined with a parallel exception handling strategy (set_exception_handler) to gracefully terminate in production environments.

Note that the above example will not respect the @ error suppression operator. If this is important to you, simply add a check with the error_reporting() function as demonstrated here:

function errHandle($errNo, $errStr, $errFile, $errLine) {
    if (error_reporting() == 0) {
        // @ suppression used, don't worry about it
        return;
    }
    // handle error here
}