SAE日志类，日志存数据库方便查阅，适用于php，支持同账户下跨应用（多个应用使用同一个db表）

PLog.class.php

<?php
/*
-- SQL
DROP TABLE IF EXISTS `t_logs`;
CREATE TABLE IF NOT EXISTS `t_logs` (
  `f_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `f_level` tinyint(4) NOT NULL,
  `f_module` varchar(128) NOT NULL,
  `f_time` int(10) unsigned NOT NULL,
  `f_path` varchar(256) NOT NULL,
  `f_line` int(10) unsigned NOT NULL,
  `f_source` varchar(256) NOT NULL,
  `f_content` text NOT NULL,
  PRIMARY KEY (`f_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COMMENT='日志表' AUTO_INCREMENT=1 ;
*/

define('CLASS_PLOG_LEVEL_TRACE',    5);
define('CLASS_PLOG_LEVEL_DEBUG',    4);
define('CLASS_PLOG_LEVEL_INFO',     3);
define('CLASS_PLOG_LEVEL_WARNING',  2);
define('CLASS_PLOG_LEVEL_ERROR',    1);

class PLog
{
    static $_instance;
    private $module;
    private $clientIp;
    private $reqFile;
    private $errCode;
    private $errMsg;

    private function __construct($module, $reqPath)
    {
        $this->module = $module;
        $this->reqFile = file_exists($reqPath) ? $reqPath : 'Unknow';
        $this->clientIp = UtilTool::GetClientIP();
        self::$_instance = $this;
    }

    private function __clone() {}
    
    public static function Init($module='')
    {
        if( ! (self::$_instance instanceof self) )
        {
            $stack	= debug_backtrace();
            $top_call = $stack[0];
            $module = strlen($module) ?  htmlspecialchars($module, ENT_QUOTES) : basename($top_call['file'], '.php');
            $file = $top_call['file'];
            self::$_instance = new self($module, $file);
        }
        return self::$_instance;
    }
    
    public function getError()
    {
        return array('errno'=> self::$_instance->errCode, 'errmsg'=> self::$_instance->errMsg);
    }
    
    public static function Trace($content='')
    {
        return self::write(CLASS_PLOG_LEVEL_TRACE, $content);
    }

    public static function Debug($content='')
    {
        return self::write(CLASS_PLOG_LEVEL_DEBUG, $content);
    }

    public static function Info($content='')
    {
        return self::write(CLASS_PLOG_LEVEL_INFO, $content);
    }

    public static function Warning($content='')
    {
        return self::write(CLASS_PLOG_LEVEL_WARNING, $content);
    }

    public static function Error($content='')
    {
        return self::write(CLASS_PLOG_LEVEL_ERROR, $content);
    }    

    private function clearErr()
    {
        self::$_instance->errCode = 0;
        self::$_instance->errMsg = '';
        return 0;
    }

    private function write($level, $content)
    {
        self::clearErr();
        $stack = debug_backtrace();
        $line = (isset($stack[1]) && isset($stack[1]['line'])) ? $stack[1]['line'] : 0;
        if (is_array($content) || is_object($content)) $content = json_encode($content);
        $content = is_string($content) ? htmlspecialchars($content, ENT_QUOTES) : $content;
        $db = new SaeMysql();
        // 跨应用
        if(defined('PLOG_DOMAIN_ID') && PLOG_DOMAIN_ID)
        {
            $db->setAppname(PLOG_DOMAIN_APP);
            $db->setAuth(PLOG_DOMAIN_ID, PLOG_DOMAIN_KEY);
        }
        $sql = 'INSERT INTO `t_logs` (`f_level`, `f_module`, `f_time`, `f_path`, `f_line`, `f_source`, `f_content`) VALUES('.
            $level. ', \''.self::$_instance->module.'\', '. time() . ', \'' .self::$_instance->reqFile.'\', '.$line.', \''. self::$_instance->clientIp . '\', \''. $content .'\')';
        // echo $sql;  exit();
        $ret = $db->run_sql($sql);
        if (0 == $db->errno())
        {
            return $ret;
        }
        self::$_instance->errCode = $db->errno();
        self::$_instance->errMsg = 'mysql error:'. $db->error();
        return false;
    }

}

用到的 UtilTool::GetClientIP() 的实现：

<?php
class UtilTool
{
    public static function GetClientIP()
    {
        $ip = '0.0.0.0';
        if (getenv("HTTP_CLIENT_IP"))
            $ip = getenv("HTTP_CLIENT_IP");
        else if(getenv("HTTP_X_FORWARDED_FOR"))
            $ip = getenv("HTTP_X_FORWARDED_FOR");
        else if(getenv("REMOTE_ADDR"))
            $ip = getenv("REMOTE_ADDR");

        $tpl = '/^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$/';

        if (preg_match($tpl, $ip) === 1)
            return $ip;
        return '0.0.0.0';
    }
}

PLog使用方法：

<?php
// test.php
require('PLog.class.php');
// init plog 
PLog::Init();

// some code...
// need log than:
PLog::Error('some error msg...');
// some code..
PLog:: Debug('some debug msg...');