常用的函数整理1(ip,时间函数,二维码)
 
	function GetIP(){ 
		if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) 
		$ip = getenv("HTTP_CLIENT_IP"); 
		else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown")) 
		$ip = getenv("HTTP_X_FORWARDED_FOR"); 
		else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) 
		$ip = getenv("REMOTE_ADDR"); 
		else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) 
		$ip = $_SERVER['REMOTE_ADDR']; 
		else 
		$ip = "unknown"; 
		return($ip); 
		}  
	
// 调用方法 :昨日           $start= strftime( "%Y-%m-%d %H:%M:%S", $this->DateAdd('d',-1,time())   );   
	function DateAdd ($interval, $number, $date) { 
		$date_time_array = getdate($date); 
		$hours = $date_time_array["hours"]; 
		$minutes = $date_time_array["minutes"]; 
		$seconds = $date_time_array["seconds"]; 
		$month = $date_time_array["mon"]; 
		$day = $date_time_array["mday"]; 
		$year = $date_time_array["year"]; 
		switch ($interval) { 
		case "yyyy": $year +=$number; break; 
		case "q": $month +=($number*3); break; 
		case "m": $month +=$number; break; 
		case "y": 
		case "d": 
		case "w": $day+=$number; break; 
		case "ww": $day+=($number*7); break; 
		case "h": $hours+=$number; break; 
		case "n": $minutes+=$number; break; 
		case "s": $seconds+=$number; break; 
		} 
		$timestamp = mktime($hours ,$minutes, $seconds,$month ,$day, $year); 
		return $timestamp;} 
//二维码生成则可以参考 phpqrcode
 
                    
                 
