How do I catch a PHP fatal (`E_ERROR`) error?

Question

I can use set_error_handler() to catch most PHP errors, but it doesn\'t work for fatal (E_ERROR) errors, such as calling a function that doesn\'t e

Answer 1

Fatal errors or recoverable fatal errors now throw instances of Error in PHP 7 or higher versions. Like any other exceptions, Error objects can be caught using a try/catch block.

Example:

<?php
$variable = 'not an object';

try {
    $variable->method(); // Throws an Error object in PHP 7 or higger.
} catch (Error $e) {
    // Handle error
    echo $e->getMessage(); // Call to a member function method() on string
}

https://3v4l.org/67vbk

Or you can use Throwable interface to catch all exceptions.

Example:

<?php
    try {
        undefinedFunctionCall();
    } catch (Throwable $e) {
        // Handle error
        echo $e->getMessage(); // Call to undefined function undefinedFunctionCall()
    }

https://3v4l.org/Br0MG

For more information: http://php.net/manual/en/language.errors.php7.php

Answer 2

You can't catch/handle fatal errors, but you can log/report them. For quick debugging I modified one answer to this simple code

function __fatalHandler()
{
    $error = error_get_last();

    // Check if it's a core/fatal error, otherwise it's a normal shutdown
    if ($error !== NULL && in_array($error['type'],
        array(E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING,
              E_COMPILE_ERROR, E_COMPILE_WARNING,E_RECOVERABLE_ERROR))) {

        echo "<pre>fatal error:\n";
        print_r($error);
        echo "</pre>";
        die;
    }
}

register_shutdown_function('__fatalHandler');

Answer 3

I developed this function to make it possible to "sandbox" code that could cause a fatal error. Since exceptions thrown from the closure register_shutdown_function don't get emitted from the pre-fatal error call stack, I'm forced to exit after this function to provide a uniform way of using it.

function superTryCatchFinallyAndExit( Closure $try, Closure $catch = NULL, Closure $finally )
{
    $finished = FALSE;
    register_shutdown_function( function() use ( &$finished, $catch, $finally ) {
        if( ! $finished ) {
            $finished = TRUE;
            print "EXPLODE!".PHP_EOL;
            if( $catch ) {
                superTryCatchFinallyAndExit( function() use ( $catch ) {
                    $catch( new Exception( "Fatal Error!!!" ) );
                }, NULL, $finally );                
            } else {
                $finally();                
            }
        }
    } );
    try {
        $try();
    } catch( Exception $e ) {
        if( $catch ) {
            try {
                $catch( $e );
            } catch( Exception $e ) {}
        }
    }
    $finished = TRUE;
    $finally();
    exit();
}

Answer 4

I developed a way to catch all error types in PHP (almost all)! I have no sure about E_CORE_ERROR (I think will not works only for that error)! But, for other fatal errors (E_ERROR, E_PARSE, E_COMPILE...) works fine using only one error handler function! There goes my solution:

Put this following code on your main file (index.php):

<?php
    define('E_FATAL',  E_ERROR | E_USER_ERROR | E_PARSE | E_CORE_ERROR |
            E_COMPILE_ERROR | E_RECOVERABLE_ERROR);

    define('ENV', 'dev');

    // Custom error handling vars
    define('DISPLAY_ERRORS', TRUE);
    define('ERROR_REPORTING', E_ALL | E_STRICT);
    define('LOG_ERRORS', TRUE);

    register_shutdown_function('shut');

    set_error_handler('handler');

    // Function to catch no user error handler function errors...
    function shut(){

        $error = error_get_last();

        if($error && ($error['type'] & E_FATAL)){
            handler($error['type'], $error['message'], $error['file'], $error['line']);
        }

    }

    function handler( $errno, $errstr, $errfile, $errline ) {

        switch ($errno){

            case E_ERROR: // 1 //
                $typestr = 'E_ERROR'; break;
            case E_WARNING: // 2 //
                $typestr = 'E_WARNING'; break;
            case E_PARSE: // 4 //
                $typestr = 'E_PARSE'; break;
            case E_NOTICE: // 8 //
                $typestr = 'E_NOTICE'; break;
            case E_CORE_ERROR: // 16 //
                $typestr = 'E_CORE_ERROR'; break;
            case E_CORE_WARNING: // 32 //
                $typestr = 'E_CORE_WARNING'; break;
            case E_COMPILE_ERROR: // 64 //
                $typestr = 'E_COMPILE_ERROR'; break;
            case E_CORE_WARNING: // 128 //
                $typestr = 'E_COMPILE_WARNING'; break;
            case E_USER_ERROR: // 256 //
                $typestr = 'E_USER_ERROR'; break;
            case E_USER_WARNING: // 512 //
                $typestr = 'E_USER_WARNING'; break;
            case E_USER_NOTICE: // 1024 //
                $typestr = 'E_USER_NOTICE'; break;
            case E_STRICT: // 2048 //
                $typestr = 'E_STRICT'; break;
            case E_RECOVERABLE_ERROR: // 4096 //
                $typestr = 'E_RECOVERABLE_ERROR'; break;
            case E_DEPRECATED: // 8192 //
                $typestr = 'E_DEPRECATED'; break;
            case E_USER_DEPRECATED: // 16384 //
                $typestr = 'E_USER_DEPRECATED'; break;
        }

        $message =
            '<b>' . $typestr .
            ': </b>' . $errstr .
            ' in <b>' . $errfile .
            '</b> on line <b>' . $errline .
            '</b><br/>';

        if(($errno & E_FATAL) && ENV === 'production'){

            header('Location: 500.html');
            header('Status: 500 Internal Server Error');

        }

        if(!($errno & ERROR_REPORTING))
            return;

        if(DISPLAY_ERRORS)
            printf('%s', $message);

        //Logging error on php file error log...
        if(LOG_ERRORS)
            error_log(strip_tags($message), 0);
    }

    ob_start();

    @include 'content.php';

    ob_end_flush();
?>

Answer 5

If you are using PHP >= 5.1.0 Just do something like this with the ErrorException class:

<?php
    // Define an error handler
    function exception_error_handler($errno, $errstr, $errfile, $errline ) {
        throw new ErrorException($errstr, $errno, 0, $errfile, $errline);
    }

    // Set your error handler
    set_error_handler("exception_error_handler");

    /* Trigger exception */
    try
    {
        // Try to do something like finding the end of the internet
    }
    catch(ErrorException $e)
    {
        // Anything you want to do with $e
    }
?>

Answer 6

Not really. Fatal errors are called that, because they are fatal. You can't recover from them.