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[讨论/交流] CodeIgniter的那些坑(二)

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发表于 2013-7-16 16:37:59 | 显示全部楼层 |阅读模式
作者:线筝
原文:http://h5b.net/codeigniter-error_report-set_error_handler/


CodeIgniter的那些坑(一)中,介绍了CodeIgniter的设置,会造成php没有任何的error.log,删掉那个设置之后,并且display_error=0之后,codeigniter偶尔还是会把错误暴露出来,这是为什么呐?
这个问题困扰了我们很久,后来我们就发现了CodeIgniter另外一个坑爹的设置,这是CodeIgniter/system/core/CodeIgniter.php的源码

PHP复制代码
<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package                CodeIgniter
 * @author                ExpressionEngine Dev Team
 * @copyright        Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license                http://codeigniter.com/user_guide/license.html
 * @link                http://codeigniter.com
 * @since                Version 1.0
 * @filesource
 */

 
// ------------------------------------------------------------------------
 
/**
 * System Initialization File
 *
 * Loads the base classes and executes the request.
 *
 * @package                CodeIgniter
 * @subpackage        codeigniter
 * @category        Front-controller
 * @author                ExpressionEngine Dev Team
 * @link                http://codeigniter.com/user_guide/
 */

 
/**
 * CodeIgniter Version
 *
 * @var string
 *
 */

        define('CI_VERSION', '2.1.3');
 
/**
 * CodeIgniter Branch (Core = TRUE, Reactor = FALSE)
 *
 * @var boolean
 *
 */

        define('CI_CORE', FALSE);
 
/*
 * ------------------------------------------------------
 *  Load the global functions
 * ------------------------------------------------------
 */

        require(BASEPATH.'core/Common.php');
 
/*
 * ------------------------------------------------------
 *  Load the framework constants
 * ------------------------------------------------------
 */

        if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/constants.php'))
        {
                require(APPPATH.'config/'.ENVIRONMENT.'/constants.php');
        }
        else
        {
                require(APPPATH.'config/constants.php');
        }
 
/*
 * ------------------------------------------------------
 *  Define a custom error handler so we can log PHP errors
 * ------------------------------------------------------
 */

        set_error_handler('_exception_handler');
 
        if ( ! is_php('5.3'))
        {
                @set_magic_quotes_runtime(0); // Kill magic quotes
        }
 
/*
 * ------------------------------------------------------
 *  Set the subclass_prefix
 * ------------------------------------------------------
 *
 * Normally the "subclass_prefix" is set in the config file.
 * The subclass prefix allows CI to know if a core class is
 * being extended via a library in the local application
 * "libraries" folder. Since CI allows config items to be
 * overriden via data set in the main index. php file,
 * before proceeding we need to know if a subclass_prefix
 * override exists.  If so, we will set this value now,
 * before any classes are loaded
 * Note: Since the config file data is cached it doesn't
 * hurt to load it here.
 */

        if (isset($assign_to_config['subclass_prefix']) AND $assign_to_config['subclass_prefix'] != '')
        {
                get_config(array('subclass_prefix' => $assign_to_config['subclass_prefix']));
        }
 
/*
 * ------------------------------------------------------
 *  Set a liberal script execution time limit
 * ------------------------------------------------------
 */

        if (function_exists("set_time_limit") == TRUE AND @ini_get("safe_mode") == 0)
        {
                @set_time_limit(300);
        }
 
/*
 * ------------------------------------------------------
 *  Start the timer... tick tock tick tock...
 * ------------------------------------------------------
 */

        $BM =& load_class('Benchmark', 'core');
        $BM->mark('total_execution_time_start');
        $BM->mark('loading_time:_base_classes_start');
 
/*
 * ------------------------------------------------------
 *  Instantiate the hooks class
 * ------------------------------------------------------
 */

        $EXT =& load_class('Hooks', 'core');
 
/*
 * ------------------------------------------------------
 *  Is there a "pre_system" hook?
 * ------------------------------------------------------
 */

        $EXT->_call_hook('pre_system');
 
/*
 * ------------------------------------------------------
 *  Instantiate the config class
 * ------------------------------------------------------
 */

        $CFG =& load_class('Config', 'core');
 
        // Do we have any manually set config items in the index.php file?
        if (isset($assign_to_config))
        {
                $CFG->_assign_to_config($assign_to_config);
        }
 
/*
 * ------------------------------------------------------
 *  Instantiate the UTF-8 class
 * ------------------------------------------------------
 *
 * Note: Order here is rather important as the UTF-8
 * class needs to be used very early on, but it cannot
 * properly determine if UTf-8 can be supported until
 * after the Config class is instantiated.
 *
 */

 
        $UNI =& load_class('Utf8', 'core');
 
/*
 * ------------------------------------------------------
 *  Instantiate the URI class
 * ------------------------------------------------------
 */

        $URI =& load_class('URI', 'core');
 
/*
 * ------------------------------------------------------
 *  Instantiate the routing class and set the routing
 * ------------------------------------------------------
 */

        $RTR =& load_class('Router', 'core');
        $RTR->_set_routing();
 
        // Set any routing overrides that may exist in the main index file
        if (isset($routing))
        {
                $RTR->_set_overrides($routing);
        }
 
/*
 * ------------------------------------------------------
 *  Instantiate the output class
 * ------------------------------------------------------
 */

        $OUT =& load_class('Output', 'core');
 
/*
 * ------------------------------------------------------
 *        Is there a valid cache file?  If so, we're done...
 * ------------------------------------------------------
 */

        if ($EXT->_call_hook('cache_override') === FALSE)
        {
                if ($OUT->_display_cache($CFG, $URI) == TRUE)
                {
                        exit;
                }
        }
 
/*
 * -----------------------------------------------------
 * Load the security class for xss and csrf support
 * -----------------------------------------------------
 */

        $SEC =& load_class('Security', 'core');
 
/*
 * ------------------------------------------------------
 *  Load the Input class and sanitize globals
 * ------------------------------------------------------
 */

        $IN        =& load_class('Input', 'core');
 
/*
 * ------------------------------------------------------
 *  Load the Language class
 * ------------------------------------------------------
 */

        $LANG =& load_class('Lang', 'core');
 
/*
 * ------------------------------------------------------
 *  Load the app controller and local controller
 * ------------------------------------------------------
 *
 */

        // Load the base controller class
        require BASEPATH.'core/Controller.php';
 
        function &get_instance()
        {
                return CI_Controller::get_instance();
        }
 
 
        if (file_exists(APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php'))
        {
                require APPPATH.'core/'.$CFG->config['subclass_prefix'].'Controller.php';
        }
 
        // Load the local application controller
        // Note: The Router class automatically validates the controller path using the router->_validate_request().
        // If this include fails it means that the default controller in the Routes.php file is not resolving to something valid.
        if ( ! file_exists(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php'))
        {
                show_error('Unable to load your default controller. Please make sure the controller specified in your Routes.php file is valid.');
        }
 
        include(APPPATH.'controllers/'.$RTR->fetch_directory().$RTR->fetch_class().'.php');
 
        // Set a mark point for benchmarking
        $BM->mark('loading_time:_base_classes_end');
 
/*
 * ------------------------------------------------------
 *  Security check
 * ------------------------------------------------------
 *
 *  None of the functions in the app controller or the
 *  loader class can be called via the URI, nor can
 *  controller functions that begin with an underscore
 */

        $class  = $RTR->fetch_class();
        $method = $RTR->fetch_method();
 
        if ( ! class_exists($class)
                OR strncmp($method, '_', 1) == 0
                OR in_array(strtolower($method), array_map('strtolower', get_class_methods('CI_Controller')))
                )
        {
                if ( ! empty($RTR->routes['404_override']))
                {
                        $x = explode('/', $RTR->routes['404_override']);
                        $class = $x[0];
                        $method = (isset($x[1]) ? $x[1] : 'index');
                        if ( ! class_exists($class))
                        {
                                if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
                                {
                                        show_404("{$class}/{$method}");
                                }
 
                                include_once(APPPATH.'controllers/'.$class.'.php');
                        }
                }
                else
                {
                        show_404("{$class}/{$method}");
                }
        }
 
/*
 * ------------------------------------------------------
 *  Is there a "pre_controller" hook?
 * ------------------------------------------------------
 */

        $EXT->_call_hook('pre_controller');
 
/*
 * ------------------------------------------------------
 *  Instantiate the requested controller
 * ------------------------------------------------------
 */

        // Mark a start point so we can benchmark the controller
        $BM->mark('controller_execution_time_( '.$class.' / '.$method.' )_start');
 
        $CI = new $class();
 
/*
 * ------------------------------------------------------
 *  Is there a "post_controller_constructor" hook?
 * ------------------------------------------------------
 */

        $EXT->_call_hook('post_controller_constructor');
 
/*
 * ------------------------------------------------------
 *  Call the requested method
 * ------------------------------------------------------
 */

        // Is there a "remap" function? If so, we call it instead
        if (method_exists($CI, '_remap'))
        {
                $CI->_remap($method, array_slice($URI->rsegments, 2));
        }
        else
        {
                // is_callable() returns TRUE on some versions of PHP 5 for private and protected
                // methods, so we'll use this workaround for consistent behavior
                if ( ! in_array(strtolower($method), array_map('strtolower', get_class_methods($CI))))
                {
                        // Check and see if we are using a 404 override and use it.
                        if ( ! empty($RTR->routes['404_override']))
                        {
                                $x = explode('/', $RTR->routes['404_override']);
                                $class = $x[0];
                                $method = (isset($x[1]) ? $x[1] : 'index');
                                if ( ! class_exists($class))
                                {
                                        if ( ! file_exists(APPPATH.'controllers/'.$class.'.php'))
                                        {
                                                show_404("{$class}/{$method}");
                                        }
 
                                        include_once(APPPATH.'controllers/'.$class.'.php');
                                        unset($CI);
                                        $CI = new $class();
                                }
                        }
                        else
                        {
                                show_404("{$class}/{$method}");
                        }
                }
 
                // Call the requested method.
                // Any URI segments present (besides the class/function) will be passed to the method for convenience
                call_user_func_array(array(&$CI, $method), array_slice($URI->rsegments, 2));
        }
 
 
        // Mark a benchmark end point
        $BM->mark('controller_execution_time_( '.$class.' / '.$method.' )_end');
 
/*
 * ------------------------------------------------------
 *  Is there a "post_controller" hook?
 * ------------------------------------------------------
 */

        $EXT->_call_hook('post_controller');
 
/*
 * ------------------------------------------------------
 *  Send the final rendered output to the browser
 * ------------------------------------------------------
 */

        if ($EXT->_call_hook('display_override') === FALSE)
        {
                $OUT->_display();
        }
 
/*
 * ------------------------------------------------------
 *  Is there a "post_system" hook?
 * ------------------------------------------------------
 */

        $EXT->_call_hook('post_system');
 
/*
 * ------------------------------------------------------
 *  Close the DB connection if one exists
 * ------------------------------------------------------
 */

        if (class_exists('CI_DB') AND isset($CI->db))
        {
                $CI->db->close();
        }
 
 
/* End of file CodeIgniter.php */
/* Location: ./system/core/CodeIgniter.php */
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在这页代码中,我们发现了这么一句话

PHP复制代码
set_error_handler('_exception_handler');
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这个函数是什么意思呐,查看php文档就会发现这么简单的介绍

Sets a user function (error_handler) to handle errors in a script.

This function can be used for defining your own way of handling errors during runtime, for example in applications in which you need to do cleanup of data/files when a critical error happens, or when you need to trigger an error under certain conditions (using trigger_error()).

It is important to remember that the standard PHP error handler is completely bypassed for the error types specified by error_types unless the callback function returns FALSE. error_reporting() settings will have no effect and your error handler will be called regardless - however you are still able to read the current value of error_reporting and act appropriately. Of particular note is that this value will be 0 if the statement that caused the error was prepended by the @ error-control operator.

Also note that it is your responsibility to die if necessary. If the error-handler function returns, script execution will continue with the next statement after the one that caused an error.

The following error types cannot be handled with a user defined function: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING, and most of E_STRICT raised in the file where set_error_handler() is called.

If errors occur before the script is executed (e.g. on file uploads) the custom error handler cannot be called since it is not registered at that time.

大致意思就是,这个函数允许程序自己去处理错误。
全局搜索_exception_handler关键词,在CodeIgniter/system/libraries/Driver.php中的CI_Driver类的一个方法中

PHP复制代码
public function __call($method, $args = array())
{
        if (in_array($method, $this->methods))
        {
                return call_user_func_array(array($this->parent, $method), $args);
        }
 
        $trace = debug_backtrace();
        _exception_handler(E_ERROR, "No such method '{$method}'", $trace[1]['file'], $trace[1]['line']);
        exit;
}
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可以看出,这个方法抛出的错误,就会被CodeIgniter钩住,自己去处理。
所以要想全部屏蔽错误的显示,就必须将CodeIgniter/system/core/CodeIgniter.php中的

PHP复制代码
set_error_handler('_exception_handler');
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干掉。

这还是只是CodeIgniter坑爹默认设置的一部分,还有CodeIgniter的那些坑(三)
发表于 2013-8-9 16:08:52 | 显示全部楼层
发表于 2016-3-21 15:53:57 | 显示全部楼层
这里的_exception_handler 只会处理call方法里产生的错误吗? 还是全局错误?
 楼主| 发表于 2016-3-21 22:37:13 | 显示全部楼层
panda_class 发表于 2016-3-21 15:53
这里的_exception_handler 只会处理call方法里产生的错误吗? 还是全局错误?

所有的错误

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