Compat.php

<?php

/**
 * PHP Compat
 *
 * Provides missing functionality in the form of constants and functions
 *   for older versions of PHP
 *
 * Optionally, you may simply include the file.
 *   e.g. require_once 'PHP/Compat/Function/scandir.php';
 *
 * PHP version 4
 *
 * @category  PHP
 * @package   PHP_Compat
 * @author    Aidan Lister <aidan@php.net>
 * @copyright 2004-2007 Aidan Lister <aidan@php.net>, Arpad Ray <arpad@php.net>
 * @license   LGPL - http://www.gnu.org/licenses/lgpl.html
 * @version   SVN: $Id$
 * @link      http://pear.php.net/package/PHP_Compat
 */

/**
 * Provides components to achieve PHP version independence
 *
 * @category  PHP
 * @package   PHP_Compat
 * @author    Aidan Lister <aidan@php.net>
 * @copyright 2004-2007 Aidan Lister <aidan@php.net>, Arpad Ray <arpad@php.net>
 * @license   LGPL - http://www.gnu.org/licenses/lgpl.html
 * @version   Release: 1.7.2
 * @link      http://pear.php.net/package/PHP_Compat
 */
class PHP_Compat
{
    /**
     * Load a function, or array of functions
     *
     * @param string|array $function The function or functions to load
     *
     * @return bool|array   TRUE if loaded, FALSE if not
     */
    function loadFunction($function)
    {
        // Multiple
        if (is_array($function)) {
            $res = array();
            foreach ($function as $singlefunc) {
                $res[$singlefunc] = PHP_Compat::loadFunction($singlefunc);
            }
            return $res;
        }
        // Check for packages which can modify the function table at runtime
        $symbolfuncs = array('rename_function', 'runkit_rename_function');
        foreach ($symbolfuncs as $symbolfunc) {
            $renamedfunction = 'php_compat_renamed' . $function;
            if (function_exists($symbolfunc) && function_exists($function)
                && !function_exists($renamedfunction)
            ) {
                    // Rename the core function
                    rename_function($function, $renamedfunction);
                    break;
            }
        }
        // Single
        if (!function_exists($function)) {
            $file = sprintf('PHP/Compat/Function/%s.php', $function);
            if ((@include_once $file) !== false) {
                return true;
            }
        }
        return false;
    }
    /**
     * Load a constant, or array of constants
     *
     * @param string|array $constant The constant or constants to load
     *
     * @return bool|array   TRUE if loaded, FALSE if not
     */
    function loadConstant($constant)
    {
        // Multiple
        if (is_array($constant)) {
            $res = array();
            foreach ($constant as $singleconst) {
                $res[$singleconst] = PHP_Compat::loadConstant($singleconst);
            }
            return $res;
        }
        // Single
        $file = sprintf('PHP/Compat/Constant/%s.php', $constant);
        if ((@include_once $file) !== false) {
            return true;
        }
        return false;
    }
    /**
     * Load an environment
     *
     * @param string $environment The environment to load
     * @param string $setting     Turn the environment on or off
     *
     * @return bool   TRUE if loaded, FALSE if not
     */
    function loadEnvironment($environment, $setting)
    {
        // Load environment
        $file = sprintf('PHP/Compat/Environment/%s_%s.php', $environment, $setting);
        if ((@include_once $file) !== false) {
            return true;
        }
        return false;
    }
    /**
     * Load components for a PHP version
     *
     * @param string $version PHP Version to load
     *
     * @return array  An associative array of component names loaded
     */
    function loadVersion($version = null)
    {
        // Include list of components
        include 'PHP/Compat/Components.php';
        // Include version_compare to work with older versions
        PHP_Compat::loadFunction('version_compare');
        // Init
        $phpver = phpversion();
        $methods = array('function' => 'loadFunction', 'constant' => 'loadConstant');
        $res = array();
        // Iterate each component
        foreach ($components as $type => $slice) {
            foreach ($slice as $component => $cver) {
                $vercom = version_compare($cver, $phpver);
                if (($version === null && $vercom === 1)  // C > PHP
                    || (version_compare($cver, $version) === 0 // C = S
                    || $vercom === 1)
                ) { // C > PHP
                        $res[$type][$component] = call_user_func(
                            array('PHP_Compat', $methods[$type]), $component
                        );
                }
            }
        }
        return $res;
    }
}