php全局事件函數

1、set_error_hander(callable $error_handler [, int $error_types = E_ALL | E_STRICT ])

2、callable set_exception_handler ( callable $exception_handler )

3、bool header_register_callback ( callable $callback ) //發送內容之前，執行callback

example

1、set_error_hander(callable $error_handler [, int $error_types = E_ALL | E_STRICT ])

bool handler ( int $errno , string $errstr [, string $errfile [, int $errline [, array $errcontext ]]] )

set_error_handler(function ($errno,$errstr,$errfile,$errline){
    if (!(error_reporting() & $errno)) {
        // This error code is not included in error_reporting, so let it fall
        // through to the standard PHP error handler
        return false;
    }

    switch ($errno) {
        case E_USER_ERROR:
            echo "<b>My ERROR</b> [$errno] $errstr<br />\n";
            echo "  Fatal error on line $errline in file $errfile";
            echo ", PHP " . PHP_VERSION . " (" . PHP_OS . ")<br />\n";
            echo "Aborting...<br />\n";
            exit(1);
            break;

        case E_USER_WARNING:
            echo "<b>My WARNING</b> [$errno] $errstr<br />\n";
            break;

        case E_USER_NOTICE:
            echo "<b>My NOTICE</b> [$errno] $errstr<br />\n";
            break;

        default:
            echo "Unknown error type: [$errno] $errstr<br />\n";
            break;
    }

    /* Don't execute PHP internal error handler */
    return true;
});

2、callable set_exception_handler ( callable $exception_handler )

void handler ( Exception $ex ) //7.0以前
void handler ( Throwable $ex ) //7.0以後

function exception_handler($exception) {
  echo "Uncaught exception: " , $exception->getMessage(), "\n";
}

3、bool header_register_callback ( callable $callback )

header_register_callback(function(){
    foreach (headers_list() as $header) {
        if (strpos($header, 'X-Powered-By:') !== false) {
            header_remove('X-Powered-By');
        }
        header_remove('X-Test');
    }
});