Catch PHP Fatal Error

Question

I have a web service site that is restful enabled, so other websites/ajax script can make a call to the site to get/set data. However, whenever the web service site somehow returns a PHP fatal error, the HTTP status that is returned is 200 instead of 500. Is there a way to fix it so that whenever a fatal error occurs, returns 500 instead of 200? Or, if it is not possible, how can I change my client to recognize the fatal error returned by the webservice?

Answer 1

PHP does send a HTTP 500 on a Fatal error.
Let me cite a comment in this PHP bug-report (a xdebug bug prevents this behavior):

It does happen. It requires that:

1) display_errors = off
2) No headers have been sent yet by the time the error happens
3) Status is 200 at that time.

<?
    ini_set('display_errors', 0); 
    foobar();
    // This will return a http 500
?>

You can catch fatal errors with a shutdown function and error_get_last:

register_shutdown_function(function() {
    $lastError = error_get_last();

    if (!empty($lastError) && $lastError['type'] == E_ERROR) {
        header('Status: 500 Internal Server Error');
        header('HTTP/1.0 500 Internal Server Error');
    }
});

Answer 2

One possible way would be to set the default response to 500, if everything executes successfully set the response to 200:

http_response_code(500);
render_my_page();
http_response_code(200);

Answer 3

Create a custom error handler (set_error_handler) and call header("HTTP/1.0 500 Service not available");.

Edit:

Per the first comment to my answer, you cannot trap true fatal errors. However, PHP will default to setting a 500 error code on fatal errors if output buffering is disabled and errors are not displayed to the screen.

<?php
        $x = y();
?>

The above code will return a 500 error code if nothing has been sent to the screen.

So if you want this kind of error to set the proper code, do your own buffering:

<?php
        $buffer = 'blah';
        $x = y();  // will trigger 500 error
        echo $buffer;
?>