$url = $_SERVER['SCRIPT_NAME'];    
                        $url .= (!emptyempty($_SERVER['QUERY_STRING'])) ? ‘?’ . 
$_SERVER['QUERY_STRING'] : ”;    
                }    
                return $url;    
        } 
         
        function warn($errorstring){  
                                echo   “<b><font   color=’red’> 发 生 错 误 :<pre>”.
$errorstring.”</pre></font></b>”;  
        }  
        
        function cache_page($pageurl,$pagedata){  
                if(!$fso=fopen($pageurl,’w')){  
                        $this->warns(‘无法打开缓存文件.’);//trigger_error  
                        return false;  
                }  
                if(!flock($fso,LOCK_EX)){//LOCK_NB,

  

排它型锁定

                        $this->warns(‘无法锁定缓存文件.’);//trigger_error  
                        return false;  
                }  
                if(!fwrite($fso,$pagedata)){//写入字节流,serialize

  

写入其他格式

                        $this->warns(‘无法写入缓存文件.’);//trigger_error  
                        return false;  
                }  
                flock($fso,LOCK_UN);//

  

释放锁定

                fclose($fso);  
                return true;  
        }  
        
        function display_cache($cacheFile){  
                if(!file_exists($cacheFile)){  
                        $this->warn(‘无法读取缓存文件.’);//trigger_error  
                        return false;  
                }  
                echo ‘读取缓存文件:’.$cacheFile;  
                //return unserialize(file_get_contents($cacheFile));  
                $fso = fopen($cacheFile, ‘r’);  
                $data = fread($fso, filesize($cacheFile));  
                fclose($fso);  
                return $data;  
        }