PHP日志LOG类定义与用法示例

<?php
/**
* php log 类 
*/
class config{
  public static function getconfig (){
   return array(
      'log_file'=>'test.txt', 
      'log_level'=>75 //info
   );
  }
}
class log{
  private $logfile;
  private $loglevel;
  const debug = 100;
  const info  = 75;
  const notice = 50;
  const warning =25;
  const error  = 10;
  const critical = 5;
  private function __construct(){
    $cfg = config::getconfig();  
    $this->loglevel = isset($cfg['log_level']) ? $cfg['log_level']:log::info;
    if(!isset($cfg['log_file']) && strlen($cfg['log_file'])){
      throw new exception('can\'t set file to empty');
    }
    $this->logfile = @fopen($cfg['log_file'],'a+');
    if(!is_resource($this->logfile)){
      throw new exception('invalid file stream');
    }
  }
  public static function getinstance(){
    static $obj;
    if(!isset($obj)){
      $obj = new log();
    }
    return $obj;
  }
  public function logmessage($msg, $loglevel = log::info,$module = null){
    if($loglevel > $this->loglevel){
      return ;
    }
    date_default_timezone_set('asia/shanghai');
    $time = strftime('%x %x',time());
    $msg = str_replace("\t",'',$msg);
    $msg = str_replace("\n",'',$msg);
    $strloglevel = $this->leveltostring($loglevel);
    if(isset($module)){
      $module = str_replace(array("\n","\t"),array("",""),$module);
    }
    $logline = "$time\t$msg\t$strloglevel\t$module\r\n";
    fwrite($this->logfile,$logline);
  }
  public function leveltostring($loglevel){
     $ret = '[unknow]';
     switch ($loglevel){
        case log::debug:
           $ret = 'log::debug';
           break;
        case log::info:
           $ret = 'log::info';
           break;
        case log::notice:
           $ret = 'log::notice';
           break;
        case log::warning:
           $ret = 'log::warning';
           break;
        case log::error:
           $ret = 'log::error';
           break;
        case log::critical:
           $ret = 'log::critical';
           break;
     }
     return $ret;
  }
}
$logins = log::getinstance();
//print_r($logins);
$logins->logmessage("test",log::info,'mytest');
?>