CI框架源码完全分析之核心文件Common.php

 0)		{			foreach ($replace as $key => $val)			{				if (isset($config[$key]))				{					$config[$key] = $val;				}			}		}		return $_config[0] =& $config;	}}// ------------------------------------------------------------------------/*** 这个就简单啦，返回配置数组中某个键名的配置值** @access	public* @return	mixed*/if ( ! function_exists('config_item')){	function config_item($item)	{		static $_config_item = array();		if ( ! isset($_config_item[$item]))		{			$config =& get_config();			if ( ! isset($config[$item]))			{				return FALSE;			}			$_config_item[$item] = $config[$item];		}		return $_config_item[$item];	}}// ------------------------------------------------------------------------/*** 错误处理** 直接显示错误信息到浏览器，都是使用core/Exception.php的方法* 默认的view文件 application/errors/errors.php** @access	public* @return	void*/if ( ! function_exists('show_error')){	function show_error($message, $status_code = 500, $heading = 'An Error Was Encountered')	{		$_error =& load_class('Exceptions', 'core');		echo $_error->show_error($heading, $message, 'error_general', $status_code);		exit;	}}// ------------------------------------------------------------------------/*** 404页面处理 * 如上相同** @access	public* @return	void*/if ( ! function_exists('show_404')){	function show_404($page = '', $log_error = TRUE)	{		$_error =& load_class('Exceptions', 'core');		$_error->show_404($page, $log_error);		exit;	}}// ------------------------------------------------------------------------/*** 记录错误日志，默认是libraries/log.php类库处理** @access	public* @return	void*/if ( ! function_exists('log_message')){	function log_message($level = 'error', $message, $php_error = FALSE)	{		static $_log;		if (config_item('log_threshold') == 0)		{			return;		}		$_log =& load_class('Log');		$_log->write_log($level, $message, $php_error);	}}// ------------------------------------------------------------------------/** * 响应一个http头，数组是常见的http头的状态码 * * @access	public * @param	int		the status code * @param	string * @return	void */if ( ! function_exists('set_status_header')){	function set_status_header($code = 200, $text = '')	{		$stati = array(							200	=> 'OK',							201	=> 'Created',							202	=> 'Accepted',							203	=> 'Non-Authoritative Information',							204	=> 'No Content',							205	=> 'Reset Content',							206	=> 'Partial Content',							300	=> 'Multiple Choices',							301	=> 'Moved Permanently',							302	=> 'Found',							304	=> 'Not Modified',							305	=> 'Use Proxy',							307	=> 'Temporary Redirect',							400	=> 'Bad Request',							401	=> 'Unauthorized',							403	=> 'Forbidden',							404	=> 'Not Found',							405	=> 'Method Not Allowed',							406	=> 'Not Acceptable',							407	=> 'Proxy Authentication Required',							408	=> 'Request Timeout',							409	=> 'Conflict',							410	=> 'Gone',							411	=> 'Length Required',							412	=> 'Precondition Failed',							413	=> 'Request Entity Too Large',							414	=> 'Request-URI Too Long',							415	=> 'Unsupported Media Type',							416	=> 'Requested Range Not Satisfiable',							417	=> 'Expectation Failed',							500	=> 'Internal Server Error',							501	=> 'Not Implemented',							502	=> 'Bad Gateway',							503	=> 'Service Unavailable',							504	=> 'Gateway Timeout',							505	=> 'HTTP Version Not Supported'						);		if ($code == '' OR ! is_numeric($code))		{			show_error('Status codes must be numeric', 500);		}		if (isset($stati[$code]) AND $text == '')		{			$text = $stati[$code];		}		if ($text == '')		{			show_error('No status text available.  Please check your status code number or supply your own message text.', 500);		}		$server_protocol = (isset($_SERVER['SERVER_PROTOCOL'])) ? $_SERVER['SERVER_PROTOCOL'] : FALSE;		if (substr(php_sapi_name(), 0, 3) == 'cgi')		{			header("Status: {$code} {$text}", TRUE);		}		elseif ($server_protocol == 'HTTP/1.1' OR $server_protocol == 'HTTP/1.0')		{			header($server_protocol." {$code} {$text}", TRUE, $code);		}		else		{			header("HTTP/1.1 {$code} {$text}", TRUE, $code);		}	}}// --------------------------------------------------------------------/*** 异常或错误出力** @access	private* @return	void*/if ( ! function_exists('_exception_handler')){	function _exception_handler($severity, $message, $filepath, $line)	{		 //E_STRICT的错误信息没用就不要了		if ($severity == E_STRICT)		{			return;		}		$_error =& load_class('Exceptions', 'core');		//这里是位运算哦，你可以看看PHP的错误级别(http://www.phpddt.com/php/error_reporting.html)                //很显然1,2,4,8...（1,10,100,1000）中任意一个与1111进行&都是它本身，根据结果显示错误		if (($severity & error_reporting()) == $severity)		{			$_error->show_php_error($severity, $message, $filepath, $line);		}		//根据配置信息是否记录错误信息日志		if (config_item('log_threshold') == 0)		{			return;		}		$_error->log_exception($severity, $message, $filepath, $line);	}}// --------------------------------------------------------------------/** * 防止在ASCII字符之间插入空字符，如Javascript. * * @access	public * @param	string * @return	string */if ( ! function_exists('remove_invisible_characters')){	function remove_invisible_characters($str, $url_encoded = TRUE)	{		$non_displayables = array();				// every control character except newline (dec 10)		// carriage return (dec 13), and horizontal tab (dec 09)				if ($url_encoded)		{			$non_displayables[] = '/%0[0-8bcef]/';	// url encoded 00-08, 11, 12, 14, 15			$non_displayables[] = '/%1[0-9a-f]/';	// url encoded 16-31		}				$non_displayables[] = '/[x00-x08x0Bx0Cx0E-x1Fx7F]+/S';	// 00-08, 11, 12, 14-31, 127		do		{			$str = preg_replace($non_displayables, '', $str, -1, $count);		}		while ($count);		return $str;	}}// ------------------------------------------------------------------------/*** 将特殊字符转化成html实体，如单引号，双引号等** @access	public* @param	mixed* @return	mixed*/if ( ! function_exists('html_escape')){	function html_escape($var)	{		if (is_array($var))		{			return array_map('html_escape', $var);		}		else		{			return htmlspecialchars($var, ENT_QUOTES, config_item('charset'));		}	}}