Catching PHP Fatal Errors with register_shutdown_function

In PHP, set_error_handler() is useful for handling most errors. However, it cannot capture fatal errors such as those caused by calling non-existent functions. To address this limitation, we can utilize register_shutdown_function.

Using register_shutdown_function

register_shutdown_function() is a function that can be called when PHP shuts down. It takes a user-defined function as a parameter. This function can then capture any unhandled errors that occurred during execution.

register_shutdown_function("fatal_handler");

function fatal_handler() {
    $error = error_get_last();
    if ($error !== NULL) {
        // Extract error information
        $errno = $error["type"];
        $errfile = $error["file"];
        $errline = $error["line"];
        $errstr = $error["message"];
        // Send error details via email using error_mail
        error_mail(format_error($errno, $errstr, $errfile, $errline));
    }
}

Additional Functions

In the above code, we have assumed the existence of two additional functions: error_mail and format_error. Here's how you can define them:

function format_error($errno, $errstr, $errfile, $errline) {
    $trace = print_r(debug_backtrace(false), true);
    $content = "..."; // Format the error message as needed
    return $content;
}

function error_mail($content) {
    // Use Swift Mailer or other mail-sending library to send the error email
}

Additional Notes

• register_shutdown_function requires PHP 5.2 or later.
• The $php_errormsg constant provides information about the most recent error.
• Refer to the predefined constants documentation for a list of error types (e.g., E_ERROR).