php 写日志

<?php
class writelog {
/**
* 写文件
* @param    string  $file   文件路径
* @param    string  $str    写入内容
* @param    char    $mode   写入模式
*
*/      
//    function writeFile($file,$str,$mode) 
    function writeFile($debug,$str)
    {
        if($debug  = 1)
      { 
          $oldmask = @umask(0); 
          $RootPath = $_SERVER['DOCUMENT_ROOT'].""; 
        $file = $RootPath.'/log/'.date('Y-m-d').'.log';  
        $str = date('m-d-s')."       " .$str."

";
        if(!file_exists($file))
        {
               $mode='w';
        } 
        else
        {
              $mode='a';
        }                                                       
      $fp = @fopen($file,$mode);
      @fwrite($fp,$str);
      @fclose($fp);
      @umask($oldmask);
    }
  }
} 

?>

调用

<?php
  require_once('./lib/writelog.php'); 
  $writelog=new writelog();
  $writelog(1,"aaa");
?>