PHP：在webserver上提供空白页面（错误500），但在本地（Smarty模板引擎）上工作正常

Question

I have a website that is built with Smarty 3 template engine in PHP 7, and when uploading it to the web server (Apache), it serves a blank page instead of the constructed html. The website works 100% perfect in the local environment, but the server seems to not like something going on.

The output I get when using,

ini_set('display_errors', 1);
error_reporting(E_ALL + E_NOTICE);
echo('<br>PHP version:' . phpversion());

is,

PHP version: 5.2.9

Fatal error: Call to undefined function spl_autoload_register() in /www/mydomain.com/html/assets/inc/vendor/smarty/Autoloader.php on line 81

Now I am positive that the two different versions of PHP aren't causing this issue, as I have uploaded and run other .php files to the server in the past (PHP 7 as well), and they display fine to the client.

What I am not understanding is how the spl_autoload_register() function is not defined because the function is definitely there on line 81 of Autoloader.php, and it's not like it isn't available to the version of PHP running on the webserver (see the docs).

Is it maybe the /html path?. The /html directory on the webserver is where the index.* file goes along with all the other pages and their assets, so I am not putting them in the wrong spot... but why is the path going from /www/mydomain.com into /html, shouldn't it be going right into /assets?

Really hope this made sense, thank you in advance!

Answer 1

Call to undefined function spl_autoload_register()

do it in index.php file:

<?php phpinfo(); die;

You'll see that SPL extension does not exist.

Maybe SPL extension not installed when was compiled from sources.

Just install new version of PHP (better 5.6) and problem will disappear.

or better upgrade Your packages:

Debian, Ubuntu and etc deb based:

apt-get update
apt-get upgrade
apt-get dist-upgrade

Arch, Gentoo and etc:

pacman -Syu

I'm Arch Linux user and have no problems with fresh stuff. (:

p.s. at last switch to normal web server or at least DigitalOcean droplet, AWS EC2 instance and etc to have full control on server and libs.

Also You can replace spl_autoload_register with replacement.

create a file called spl_autoload_register.php in relative folder and put this code:

<?php

if (!function_exists('spl_autoload_register')):
    $_spl_autoloaders = array();

    /**
     * Autoloader compatibility callback.
     */
    function __autoload($classname)
    {
        global $_spl_autoloaders;
        foreach ($_spl_autoloaders as $autoloader) {
            if (!is_callable($autoloader)) {
                continue;
            }

            call_user_func($autoloader, $classname);

            if (class_exists($classname, false)) {
                return;
            }
        }
    }

    /**
     * Register a function to be autoloaded.
     */
    function spl_autoload_register($autoload_function, $throw = true, $prepend = false) {
        if ($throw && !is_callable($autoload_function)) {
            throw new Exception('Function not callable');
        }

        global $_spl_autoloaders;

        if (in_array($autoload_function, $_spl_autoloaders)) {
            return;
        }

        if ($prepend) {
            array_unshift($_spl_autoloaders, $autoload_function);
            return;
        }

        $_spl_autoloaders[] = $autoload_function;
    }

    /**
     * Unregister an autoloader function.
     */
    function spl_autoload_unregister($function) {
        global $_spl_autoloaders;

        foreach ($_spl_autoloaders as &$autoloader) {
            if ($autoloader === $function) {
                unset($autoloader);
                return true;
            }
        }
        return false;
    }

    /**
     * Get the registered autoloader functions.
     */
    function spl_autoload_functions() {
        return $GLOBALS['_spl_autoloaders'];
    }
endif;

and then in top of main file of Your app require it:

require_once 'spl_autoload_register.php';

this code will replace missing spl_autoload_register function with custom one that works identically same.