个人抽离出来一个超级简易但是实用的代码段

public static function WriteLog($msg,$module = null,$logLevel = "DEBUG")    {        $filepath = $_SESSION["APP_ROOT"]."/log/";        if(!is_dir($filepath)) mkdir($filepath,'0777');        $MyLogFile = @fopen($filepath.date("Y-m-d").".txt",'a+');            $time = date("Y-m-d H:i:s");        if(isset($module)){
   $module =  sprintf("\r\n归属模块：".$module."\r\n");}        $logLine = "\r\n-------------------------------  $time -------------------------------\r\n";        $logLine .= $module;        $logLine .= "\r\n异常信息：$msg\r\n";        $logLine .= "\r\n错误等级：$logLevel\r\n";        fwrite($MyLogFile,$logLine);    }

网上拿下来的：

     logLevel = 100;        $filepath = $_SESSION["APP_ROOT"]."/log/";        $filename = date("Y-m-d").".txt";        if(!is_dir($filepath)) mkdir($filepath,'0777');        $this->LogFile = @fopen($filepath.$filename,'a+');       }      public static function getInstance()    {        static $obj;        if(!isset($obj)){            $obj = new mylog();        }        return $obj;    }        public static function WriteLog($msg,$module = null,$logLevel = "DEBUG")    {        $filepath = $_SESSION["APP_ROOT"]."/log/";        if(!is_dir($filepath)) mkdir($filepath,'0777');        $MyLogFile = @fopen($filepath.date("Y-m-d").".txt",'a+');                     $time = date("Y-m-d H:i:s");        if(isset($module)){
   $module =  sprintf("\r\n归属模块：".$module."\r\n");}        $logLine = "\r\n-------------------------------  $time -------------------------------\r\n";        $logLine .= $module;        $logLine .= "\r\n异常信息：$msg\r\n";       $logLine .= "\r\n错误等级：$logLevel\r\n";        fwrite($MyLogFile,$logLine);            }        public  function LogMessage($msg,$module = null,$logLevel = mylog::DEBUG)    {         $time = date("Y-m-d H:i:s");         $strLogLevel = $this->levelToString($logLevel);         if(isset($module)){
   $module =  sprintf("\r\n归属模块：".$module."\r\n");}         $logLine = "\r\n-------------------------------  $time -------------------------------\r\n";         $logLine .= $module;         $logLine .= "\r\n错误信息：$msg\r\n";         $logLine .= "\r\n错误等级：$strLogLevel\r\n";         fwrite($this->LogFile,$logLine);    }    public function levelToString($logLevel)    {         $ret = '[unknow]';         switch ($logLevel){                case mylog::DEBUG:                     $ret = 'DEBUG';                     break;                case mylog::INFO:                     $ret = 'INFO';                     break;                case mylog::NOTICE:                     $ret = 'NOTICE';                     break;                case mylog::WARNING:                     $ret = 'WARNING';                     break;                case mylog::ERROR:                     $ret = 'ERROR';                     break;                case mylog::CRITICAL:                     $ret = 'CRITICAL';                     break;         }         return $ret;    }}?>
     LogMessage("测试一下"); //或者//      mylog::WriteLog("可以了");?>