CI框架源码完全分析之核心文件Common.php
CI框架core/Common.php中都是一些公共的函数，如：
- is_really_writable() 兼容windows/linux的判断文件是否有写入权限
- is_php() 判断php的版本
- load_class() 加载并实例化类
- get_config() 获取配置文件，返回配置数组
- config_item() 返回配置文件中的一个信息
- show_error() 错误处理
- show_404() 404处理
- log_message() 消息日志记录
- _exception_handler() 异常或错误处理
- set_status_header 响应头
- 等等
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, $line);
}
}
// --------------------------------------------------------------------
/**
* 防止在ASCII字符之间插入空字符，如Java\0script.
*
* @access public
* @param string
* @return string
*/
if ( ! function_exists('remove_invisible_characters'))
{
function remove_invisible_characters($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-\x08\x0B\x0C\x0E-\x1F\x7F]+/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'));
}
}
}
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