Question

My app has a registered shutdown function and it seems there’s some issues with that and my method of using an exception with a try/catch to exit the application (instead of using the exit() method due to FastCGI not liking this).

My problem is that if another exception is thrown in the try/catch block that isn’t the ExitApp exception, it causes some unexpected results and the end result is the ExitApp exception isn’t caught.

I’m seeing this on PHP 5.3.6, going to test it on another version now, but I’m curious if anyone can immediately point out what’s wrong here.

<?php

// Define dummy exception class
class ExitApp extends Exception {}

try {
    // Define shutdown function
    function shutdown() {
        echo "Shutting down...";
        throw new ExitApp;
    }

    register_shutdown_function("shutdown");

    // Throw exception!
    throw new Exception("EXCEPTION!");
} catch(ExitApp $e) {
    echo "Catching the exit exception!";
}

/**
 * Expected Result: Uncaught Exception Error and then "Catching the exit exception!" is printed.
 * Actual Result: Uncaught Exception Error for "Exception" and then Uncaught Exception Error for "ExitApp" even though it's being caught.
 */

Answer 1

You have wrong expectations from your code. Firstly, if you throw exception in your shutdown function, you will always end up with uncaught exception – shutdown functions are called outside tr/catch block.

Secondly you have no attempt to intercept unknown exception – you are only catching ExitApp types. you may want to try something like this:

try {
    //some stuff
} catch(ExitApp $ea) {
    //normal exit, nothing to do here
} catch(Exception $e){
    //something rather unexpected, log it
}