最完整PHP常用工具类大全，_PHP教程

<?php
/**
 * 助手类
 * @author www.shouce.ren
 */
class Helper
{
	/**
	 * 判断当前服务器系统
	 * @return string
	 */
	public static function getOS(){
		if(PATH_SEPARATOR == ':'){
			return 'Linux';
		}else{
			return 'Windows';
		}
	}
	/**
	 * 当前微妙数
	 * @return number
	 */
	public static function microtime_float() {
		list ( $usec, $sec ) = explode ( " ", microtime () );
		return (( float ) $usec + ( float ) $sec);
	}

	/**
	 * 切割utf-8格式的字符串(一个汉字或者字符占一个字节)
	 *
	 * @author zhao jinhan
	 * @version v1.0.0
	 *
	 */
	public static function truncate_utf8_string($string, $length, $etc = '...') {
		$result = '';
		$string = html_entity_decode ( trim ( strip_tags ( $string ) ), ENT_QUOTES, 'UTF-8' );
		$strlen = strlen ( $string );
		for($i = 0; (($i < $strlen) && ($length > 0)); $i ++) {
			if ($number = strpos ( str_pad ( decbin ( ord ( substr ( $string, $i, 1 ) ) ), 8, '0', STR_PAD_LEFT ), '0' )) {
				if ($length < 1.0) {
					break;
				}
				$result .= substr ( $string, $i, $number );
				$length -= 1.0;
				$i += $number - 1;
			} else {
				$result .= substr ( $string, $i, 1 );
				$length -= 0.5;
			}
		}
		$result = htmlspecialchars ( $result, ENT_QUOTES, 'UTF-8' );
		if ($i < $strlen) {
			$result .= $etc;
		}
		return $result;
	}

	/**
	 * 遍历文件夹
	 * @param string $dir
	 * @param boolean $all  true表示递归遍历
	 * @return array
	 */
	public static function scanfDir($dir='', $all = false, &$ret = array()){
		if ( false !== ($handle = opendir ( $dir ))) {
			while ( false !== ($file = readdir ( $handle )) ) {
				if (!in_array($file, array('.', '..', '.git', '.gitignore', '.svn', '.htaccess', '.buildpath','.project'))) {
					$cur_path = $dir . '/' . $file;
					if (is_dir ( $cur_path )) {
						$ret['dirs'][] =$cur_path;
						$all && self::scanfDir( $cur_path, $all, $ret);
					} else {
						$ret ['files'] [] = $cur_path;
					}
				}
			}
			closedir ( $handle );
		}
		return $ret;
	}

	/**
	 * 邮件发送
	 * @param string $toemail
	 * @param string $subject
	 * @param string $message
	 * @return boolean
	 */
	public static function sendMail($toemail = '', $subject = '', $message = '') {
		$mailer = Yii::createComponent ( 'application.extensions.mailer.EMailer' );

		//邮件配置
		$mailer->SetLanguage('zh_cn');
		$mailer->Host = Yii::app()->params['emailHost']; //发送邮件服务器
		$mailer->Port = Yii::app()->params['emailPort']; //邮件端口
		$mailer->Timeout = Yii::app()->params['emailTimeout'];//邮件发送超时时间
		$mailer->ContentType = 'text/html';//设置html格式
		$mailer->SMTPAuth = true;
		$mailer->Username = Yii::app()->params['emailUserName'];
		$mailer->Password = Yii::app()->params['emailPassword'];
		$mailer->IsSMTP ();
		$mailer->From = $mailer->Username; // 发件人邮箱
		$mailer->FromName = Yii::app()->params['emailFormName']; // 发件人姓名
		$mailer->AddReplyTo ( $mailer->Username );
		$mailer->CharSet = 'UTF-8';

		// 添加邮件日志
		$modelMail = new MailLog ();
		$modelMail->accept = $toemail;
		$modelMail->subject = $subject;
		$modelMail->message = $message;
		$modelMail->send_status = 'waiting';
		$modelMail->save ();
		// 发送邮件
		$mailer->AddAddress ( $toemail );
		$mailer->Subject = $subject;
		$mailer->Body = $message;

		if ($mailer->Send () === true) {
			$modelMail->times = $modelMail->times + 1;
			$modelMail->send_status = 'success';
			$modelMail->save ();
			return true;
		} else {
			$error = $mailer->ErrorInfo;
			$modelMail->times = $modelMail->times + 1;
			$modelMail->send_status = 'failed';
			$modelMail->error = $error;
			$modelMail->save ();
			return false;
		}
	}

	/**
	 * 判断字符串是utf-8 还是gb2312
	 * @param unknown $str
	 * @param string $default
	 * @return string
	 */
	public static function utf8_gb2312($str, $default = 'gb2312')
	{
	    $str = preg_replace("/[\x01-\x7F]+/", "", $str);
	    if (empty($str)) return $default;

	    $preg =  array(
	        "gb2312" => "/^([\xA1-\xF7][\xA0-\xFE])+$/", //正则判断是否是gb2312
	        "utf-8" => "/^[\x{4E00}-\x{9FA5}]+$/u",      //正则判断是否是汉字(utf8编码的条件了)，这个范围实际上已经包含了繁体中文字了
	    );

	    if ($default == 'gb2312') {
	        $option = 'utf-8';
	    } else {
	        $option = 'gb2312';
	    }

	    if (!preg_match($preg[$default], $str)) {
	        return $option;
	    }
	    $str = @iconv($default, $option, $str);

	    //不能转成 $option, 说明原来的不是 $default
	    if (empty($str)) {
	        return $option;
	    }
	    return $default;
	}
	/**
	 * utf-8和gb2312自动转化
	 * @param unknown $string
	 * @param string $outEncoding
	 * @return unknown|string
	 */
	public static function safeEncoding($string,$outEncoding = 'UTF-8')
	{
		$encoding = "UTF-8";
		for($i = 0; $i < strlen ( $string ); $i ++) {
			if (ord ( $string {$i} ) < 128)
				continue;

			if ((ord ( $string {$i} ) & 224) == 224) {
				// 第一个字节判断通过
				$char = $string {++ $i};
				if ((ord ( $char ) & 128) == 128) {
					// 第二个字节判断通过
					$char = $string {++ $i};
					if ((ord ( $char ) & 128) == 128) {
						$encoding = "UTF-8";
						break;
					}
				}
			}
			if ((ord ( $string {$i} ) & 192) == 192) {
				// 第一个字节判断通过
				$char = $string {++ $i};
				if ((ord ( $char ) & 128) == 128) {
					// 第二个字节判断通过
					$encoding = "GB2312";
					break;
				}
			}
		}

		if (strtoupper ( $encoding ) == strtoupper ( $outEncoding ))
			return $string;
		else
			return @iconv ( $encoding, $outEncoding, $string );
	}
	/**
	 * 返回二维数组中某个键名的所有值
	 * @param input $array
	 * @param string $key
	 * @return array
	 */
	public static function array_key_values($array =array(), $key='')
	{
		$ret = array();
		foreach((array)$array as $k=>$v){
			$ret[$k] = $v[$key];
		}
		return $ret;
	}


	/**
	 * 判断 文件/目录 是否可写（取代系统自带的 is_writeable 函数）
	 * @param string $file 文件/目录
	 * @return boolean
	 */
	public static function is_writeable($file) {
		if (is_dir($file)){
			$dir = $file;
			if ($fp = @fopen("$dir/test.txt", 'w')) {
				@fclose($fp);
				@unlink("$dir/test.txt");
				$writeable = 1;
			} else {
				$writeable = 0;
			}
		} else {
			if ($fp = @fopen($file, 'a+')) {
				@fclose($fp);
				$writeable = 1;
			} else {
				$writeable = 0;
			}
		}

		return $writeable;
	}
	/**
	 * 格式化单位
	 */
	static public function byteFormat( $size, $dec = 2 ) {
		$a = array ( "B" , "KB" , "MB" , "GB" , "TB" , "PB" );
		$pos = 0;
		while ( $size >= 1024 ) {
			$size /= 1024;
			$pos ++;
		}
		return round( $size, $dec ) . " " . $a[$pos];
	}

	/**
	 * 下拉框，单选按钮 自动选择
	 *
	 * @param $string 输入字符
	 * @param $param  条件
	 * @param $type   类型
	 * selected checked
	 * @return string
	 */
	static public function selected( $string, $param = 1, $type = 'select' ) {

		$true = false;
		if ( is_array( $param ) ) {
			$true = in_array( $string, $param );
		}elseif ( $string == $param ) {
			$true = true;
		}
		$return='';
		if ( $true )
			$return = $type == 'select' ? 'selected="selected"' : 'checked="checked"';

		echo $return;
	}

	/**
	 * 下载远程图片
	 * @param string $url 图片的绝对url
	 * @param string $filepath 文件的完整路径（例如/www/images/test） ，此函数会自动根据图片url和http头信息确定图片的后缀名
	 * @param string $filename 要保存的文件名(不含扩展名)
	 * @return mixed 下载成功返回一个描述图片信息的数组，下载失败则返回false
	 */
	static public function downloadImage($url, $filepath, $filename) {
		//服务器返回的头信息
		$responseHeaders = array();
		//原始图片名
		$originalfilename = '';
		//图片的后缀名
		$ext = '';
		$ch = curl_init($url);
		//设置curl_exec返回的值包含Http头
		curl_setopt($ch, CURLOPT_HEADER, 1);
		//设置curl_exec返回的值包含Http内容
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		//设置抓取跳转（http 301，302）后的页面
		curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
		//设置最多的HTTP重定向的数量
		curl_setopt($ch, CURLOPT_MAXREDIRS, 3);

		//服务器返回的数据（包括http头信息和内容）
		$html = curl_exec($ch);
		//获取此次抓取的相关信息
		$httpinfo = curl_getinfo($ch);
		curl_close($ch);
		if ($html !== false) {
			//分离response的header和body，由于服务器可能使用了302跳转，所以此处需要将字符串分离为 2+跳转次数 个子串
			$httpArr = explode("\r\n\r\n", $html, 2 + $httpinfo['redirect_count']);
			//倒数第二段是服务器最后一次response的http头
			$header = $httpArr[count($httpArr) - 2];
			//倒数第一段是服务器最后一次response的内容
			$body = $httpArr[count($httpArr) - 1];
			$header.="\r\n";

			//获取最后一次response的header信息
			preg_match_all('/([a-z0-9-_]+):\s*([^\r\n]+)\r\n/i', $header, $matches);
			if (!empty($matches) && count($matches) == 3 && !empty($matches[1]) && !empty($matches[1])) {
				for ($i = 0; $i < count($matches[1]); $i++) {
					if (array_key_exists($i, $matches[2])) {
						$responseHeaders[$matches[1][$i]] = $matches[2][$i];
					}
				}
			}
			//获取图片后缀名
			if (0 < preg_match('{(?:[^\/\\\\]+)\.(jpg|jpeg|gif|png|bmp)$}i', $url, $matches)) {
				$originalfilename = $matches[0];
				$ext = $matches[1];
			} else {
				if (array_key_exists('Content-Type', $responseHeaders)) {
					if (0 < preg_match('{image/(\w+)}i', $responseHeaders['Content-Type'], $extmatches)) {
						$ext = $extmatches[1];
					}
				}
			}
			//保存文件
			if (!empty($ext)) {
				//如果目录不存在，则先要创建目录
				if(!is_dir($filepath)){
					mkdir($filepath, 0777, true);
				}

				$filepath .= '/'.$filename.".$ext";
				$local_file = fopen($filepath, 'w');
				if (false !== $local_file) {
					if (false !== fwrite($local_file, $body)) {
						fclose($local_file);
						$sizeinfo = getimagesize($filepath);
						return array('filepath' => realpath($filepath), 'width' => $sizeinfo[0], 'height' => $sizeinfo[1], 'orginalfilename' => $originalfilename, 'filename' => pathinfo($filepath, PATHINFO_BASENAME));
					}
				}
			}
		}
		return false;
	}


	/**
	 * 查找ip是否在某个段位里面
	 * @param string $ip 要查询的ip
	 * @param $arrIP     禁止的ip
	 * @return boolean
	 */
	public static function ipAccess($ip='0.0.0.0', $arrIP = array()){
		$access = true;
		$ip && $arr_cur_ip = explode('.', $ip);
		foreach((array)$arrIP as $key=> $value){
			if($value == '*.*.*.*'){
				$access = false; //禁止所有
				break;
			}
			$tmp_arr = explode('.', $value);
			if(($arr_cur_ip[0] == $tmp_arr[0]) && ($arr_cur_ip[1] == $tmp_arr[1])) {
				//前两段相同
				if(($arr_cur_ip[2] == $tmp_arr[2]) || ($tmp_arr[2] == '*')){
					//第三段为* 或者相同
					if(($arr_cur_ip[3] == $tmp_arr[3]) || ($tmp_arr[3] == '*')){
						//第四段为* 或者相同
						$access = false; //在禁止ip列，则禁止访问
						break;
					}
				}
			}
		}
		return $access;
	}

	/**
	 * @param string $string 原文或者密文
	 * @param string $operation 操作(ENCODE | DECODE), 默认为 DECODE
	 * @param string $key 密钥
	 * @param int $expiry 密文有效期, 加密时候有效， 单位 秒，0 为永久有效
	 * @return string 处理后的 原文或者 经过 base64_encode 处理后的密文
	 *
	 * @example
	 *
	 * $a = authcode('abc', 'ENCODE', 'key');
	 * $b = authcode($a, 'DECODE', 'key');  // $b(abc)
	 *
	 * $a = authcode('abc', 'ENCODE', 'key', 3600);
	 * $b = authcode('abc', 'DECODE', 'key'); // 在一个小时内，$b(abc)，否则 $b 为空
	 */
	public static function authcode($string, $operation = 'DECODE', $key = '', $expiry = 3600) {

		$ckey_length = 4;
		// 随机密钥长度 取值 0-32;
		// 加入随机密钥，可以令密文无任何规律，即便是原文和密钥完全相同，加密结果也会每次不同，增大破解难度。
		// 取值越大，密文变动规律越大，密文变化 = 16 的 $ckey_length 次方
		// 当此值为 0 时，则不产生随机密钥


		$key = md5 ( $key ? $key : 'key' ); //这里可以填写默认key值
		$keya = md5 ( substr ( $key, 0, 16 ) );
		$keyb = md5 ( substr ( $key, 16, 16 ) );
		$keyc = $ckey_length ? ($operation == 'DECODE' ? substr ( $string, 0, $ckey_length ) : substr ( md5 ( microtime () ), - $ckey_length )) : '';

		$cryptkey = $keya . md5 ( $keya . $keyc );
		$key_length = strlen ( $cryptkey );

		$string = $operation == 'DECODE' ? base64_decode ( substr ( $string, $ckey_length ) ) : sprintf ( '%010d', $expiry ? $expiry + time () : 0 ) . substr ( md5 ( $string . $keyb ), 0, 16 ) . $string;
		$string_length = strlen ( $string );

		$result = '';
		$box = range ( 0, 255 );

		$rndkey = array ();
		for($i = 0; $i <= 255; $i ++) {
			$rndkey [$i] = ord ( $cryptkey [$i % $key_length] );
		}

		for($j = $i = 0; $i < 256; $i ++) {
			$j = ($j + $box [$i] + $rndkey [$i]) % 256;
			$tmp = $box [$i];
			$box [$i] = $box [$j];
			$box [$j] = $tmp;
		}

		for($a = $j = $i = 0; $i < $string_length; $i ++) {
			$a = ($a + 1) % 256;
			$j = ($j + $box [$a]) % 256;
			$tmp = $box [$a];
			$box [$a] = $box [$j];
			$box [$j] = $tmp;
			$result .= chr ( ord ( $string [$i] ) ^ ($box [($box [$a] + $box [$j]) % 256]) );
		}

		if ($operation == 'DECODE') {
			if ((substr ( $result, 0, 10 ) == 0 || substr ( $result, 0, 10 ) - time () > 0) && substr ( $result, 10, 16 ) == substr ( md5 ( substr ( $result, 26 ) . $keyb ), 0, 16 )) {
				return substr ( $result, 26 );
			} else {
				return '';
			}
		} else {
			return $keyc . str_replace ( '=', '', base64_encode ( $result ) );
		}

	}

	public static function gbkToUtf8($str){
		return iconv("GBK", "UTF-8", $str);
	}

	/**
	 * 取得输入目录所包含的所有目录和文件
	 * 以关联数组形式返回
	 * author: flynetcn
	 */
	static public function deepScanDir($dir)
	{
		$fileArr = array();
		$dirArr = array();
		$dir = rtrim($dir, '//');
		if(is_dir($dir)){
			$dirHandle = opendir($dir);
			while(false !== ($fileName = readdir($dirHandle))){
				$subFile = $dir . DIRECTORY_SEPARATOR . $fileName;
				if(is_file($subFile)){
					$fileArr[] = $subFile;
				} elseif (is_dir($subFile) && str_replace('.', '', $fileName)!=''){
					$dirArr[] = $subFile;
					$arr = self::deepScanDir($subFile);
					$dirArr = array_merge($dirArr, $arr['dir']);
					$fileArr = array_merge($fileArr, $arr['file']);
				}
			}
			closedir($dirHandle);
		}
		return array('dir'=>$dirArr, 'file'=>$fileArr);
	}


	/**
	 * 取得输入目录所包含的所有文件
	 * 以数组形式返回
	 * author: flynetcn
	 */
	static public function get_dir_files($dir)
	{
		if (is_file($dir)) {
			return array($dir);
		}
		$files = array();
		if (is_dir($dir) && ($dir_p = opendir($dir))) {
			$ds = DIRECTORY_SEPARATOR;
			while (($filename = readdir($dir_p)) !== false) {
				if ($filename=='.' || $filename=='..') { continue; }
				$filetype = filetype($dir.$ds.$filename);
				if ($filetype == 'dir') {
					$files = array_merge($files, self::get_dir_files($dir.$ds.$filename));
				} elseif ($filetype == 'file') {
					$files[] = $dir.$ds.$filename;
				}
			}
			closedir($dir_p);
		}
		return $files;
	}

	/**
	 * 删除文件夹及其文件夹下所有文件
	 */
	public static function deldir($dir) {
		//先删除目录下的文件：
		$dh=opendir($dir);
		while ($file=readdir($dh)) {
			if($file!="." && $file!="..") {
				$fullpath=$dir."/".$file;
				if(!is_dir($fullpath)) {
					unlink($fullpath);
				} else {
					self::deldir($fullpath);
				}
			}
		}

		closedir($dh);
		//删除当前文件夹：
		if(rmdir($dir)) {
			return true;
		} else {
			return false;
		}
	}

		/**
		 * js 弹窗并且跳转
		 * @param string $_info
		 * @param string $_url
		 * @return js
		 */
		static public function alertLocation($_info, $_url) {
			echo "<script type='text/javascript'>alert('$_info');location.href='$_url';</script>";
			exit();
		}

		/**
		 * js 弹窗返回
		 * @param string $_info
		 * @return js
		 */
		static public function alertBack($_info) {
			echo "<script type='text/javascript'>alert('$_info');history.back();</script>";
			exit();
		}

		/**
		 * 页面跳转
		 * @param string $url
		 * @return js
		 */
		static public function headerUrl($url) {
			echo "<script type='text/javascript'>location.href='{$url}';</script>";
			exit();
		}

		/**
		 * 弹窗关闭
		 * @param string $_info
		 * @return js
		 */
		static public function alertClose($_info) {
			echo "<script type='text/javascript'>alert('$_info');close();</script>";
			exit();
		}

		/**
		 * 弹窗
		 * @param string $_info
		 * @return js
		 */
		static public function alert($_info) {
			echo "<script type='text/javascript'>alert('$_info');</script>";
			exit();
		}

		/**
		 * 系统基本参数上传图片专用
		 * @param string $_path
		 * @return null
		 */
		static public function sysUploadImg($_path) {
			echo '<script type="text/javascript">document.getElementById("logo").value="'.$_path.'";</script>';
			echo '<script type="text/javascript">document.getElementById("pic").src="'.$_path.'";</script>';
			echo '<script type="text/javascript">$("#loginpop1").hide();</script>';
			echo '<script type="text/javascript">$("#bgloginpop2").hide();</script>';
		}

		/**
		 * html过滤
		 * @param array|object $_date
		 * @return string
		 */
		static public function htmlString($_date) {
			if (is_array($_date)) {
				foreach ($_date as $_key=>$_value) {
					$_string[$_key] = self::htmlString($_value);  //递归
				}
			} elseif (is_object($_date)) {
				foreach ($_date as $_key=>$_value) {
					$_string->$_key = self::htmlString($_value);  //递归
				}
			} else {
				$_string = htmlspecialchars($_date);
			}
			return $_string;
		}

		/**
		 * 数据库输入过滤
		 * @param string $_data
		 * @return string
		 */
		static public function mysqlString($_data) {
			$_data = trim($_data);
			return !GPC ? addcslashes($_data) : $_data;
		}

		/**
		 * 清理session
		 */
		static public function unSession() {
			if (session_start()) {
				session_destroy();
			}
		}

		/**
		 * 验证是否为空
		 * @param string $str
		 * @param string $name
		 * @return bool (true or false)
		 */
		static function validateEmpty($str, $name) {
			if (empty($str)) {
				self::alertBack('警告：' .$name . '不能为空！');
			}
		}

		/**
		 * 验证是否相同
		 * @param string $str1
		 * @param string $str2
		 * @param string $alert
		 * @return JS
		 */
		static function validateAll($str1, $str2, $alert) {
			if ($str1 != $str2) self::alertBack('警告：' .$alert);
		}

		/**
		 * 验证ID
		 * @param Number $id
		 * @return JS
		 */
		static function validateId($id) {
			if (empty($id) || !is_numeric($id)) self::alertBack('警告：参数错误！');
		}

		/**
		 * 格式化字符串
		 * @param string $str
		 * @return string
		 */
		static public function formatStr($str) {
			$arr = array(' ', '	', '&', '@', '#', '%',  '\'', '"', '\\', '/', '.', ',', '$', '^', '*', '(', ')', '[', ']', '{', '}', '|', '~', '`', '?', '!', ';', ':', '-', '_', '+', '=');
			foreach ($arr as $v) {
				$str = str_replace($v, '', $str);
			}
			return $str;
		}

		/**
		 * 格式化时间
		 * @param int $time 时间戳
		 * @return string
		 */
		static public function formatDate($time='default') {
			$date = $time == 'default' ? date('Y-m-d H:i:s', time()) : date('Y-m-d H:i:s', $time);
			return $date;
		}

		/**
		 * 获得真实IP地址
		 * @return string
		 */
		static public function realIp() {
			static $realip = NULL;
			if ($realip !== NULL) return $realip;
			if (isset($_SERVER)) {
				if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
					$arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
					foreach ($arr AS $ip) {
						$ip = trim($ip);
						if ($ip != 'unknown') {
							$realip = $ip;
							break;
						}
					}
				} elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
					$realip = $_SERVER['HTTP_CLIENT_IP'];
				} else {
					if (isset($_SERVER['REMOTE_ADDR'])) {
						$realip = $_SERVER['REMOTE_ADDR'];
					} else {
						$realip = '0.0.0.0';
					}
				}
			} else {
				if (getenv('HTTP_X_FORWARDED_FOR')) {
					$realip = getenv('HTTP_X_FORWARDED_FOR');
				} elseif (getenv('HTTP_CLIENT_IP')) {
					$realip = getenv('HTTP_CLIENT_IP');
				} else {
					$realip = getenv('REMOTE_ADDR');
				}
			}
			preg_match('/[\d\.]{7,15}/', $realip, $onlineip);
			$realip = !empty($onlineip[0]) ? $onlineip[0] : '0.0.0.0';
			return $realip;
		}

		/**
		 * 加载 Smarty 模板
		 * @param string $html
		 * @return null;
		 */
		static public function display() {
			global $tpl;$html = null;
			$htmlArr = explode('/', $_SERVER[SCRIPT_NAME]);
			$html = str_ireplace('.php', '.html', $htmlArr[count($htmlArr)-1]);
			$dir = dirname($_SERVER[SCRIPT_NAME]);
			$firstStr = substr($dir, 0, 1);
			$endStr = substr($dir, strlen($dir)-1, 1);
			if ($firstStr == '/' || $firstStr == '\\') $dir = substr($dir, 1);
			if ($endStr != '/' || $endStr != '\\') $dir = $dir . '/';
			$tpl->display($dir.$html);
		}

		/**
		 * 创建目录
		 * @param string $dir
		 */
		static public function createDir($dir) {
			if (!is_dir($dir)) {
				mkdir($dir, 0777);
			}
		}

		/**
		 * 创建文件（默认为空）
		 * @param unknown_type $filename
		 */
		static public function createFile($filename) {
			if (!is_file($filename)) touch($filename);
		}

		/**
		 * 正确获取变量
		 * @param string $param
		 * @param string $type
		 * @return string
		 */
		static public function getData($param, $type='post') {
			$type = strtolower($type);
			if ($type=='post') {
				return self::mysqlString(trim($_POST[$param]));
			} elseif ($type=='get') {
				return self::mysqlString(trim($_GET[$param]));
			}
		}

		/**
		 * 删除文件
		 * @param string $filename
		 */
		static public function delFile($filename) {
			if (file_exists($filename)) unlink($filename);
		}

		/**
		 * 删除目录
		 * @param string $path
		 */
		static public function delDir($path) {
			if (is_dir($path)) rmdir($path);
		}

		/**
		 * 删除目录及地下的全部文件
		 * @param string $dir
		 * @return bool
		 */
		static public function delDirOfAll($dir) {
			//先删除目录下的文件：
			if (is_dir($dir)) {
				$dh=opendir($dir);
				while (!!$file=readdir($dh)) {
					if($file!="." && $file!="..") {
						$fullpath=$dir."/".$file;
						if(!is_dir($fullpath)) {
							unlink($fullpath);
						} else {
							self::delDirOfAll($fullpath);
						}
					}
				}
				closedir($dh);
				//删除当前文件夹：
				if(rmdir($dir)) {
					return true;
				} else {
					return false;
				}
			}
		}

		/**
		 * 验证登陆
		 */
		static public function validateLogin() {
			if (empty($_SESSION['admin']['user'])) header('Location:/admin/');
		}

		/**
		 * 给已经存在的图片添加水印
		 * @param string $file_path
		 * @return bool
		 */
		static public function addMark($file_path) {
			if (file_exists($file_path) && file_exists(MARK)) {
				//求出上传图片的名称后缀
				$ext_name = strtolower(substr($file_path, strrpos($file_path, '.'), strlen($file_path)));
				//$new_name='jzy_' . time() . rand(1000,9999) . $ext_name ;
				$store_path = ROOT_PATH . UPDIR;
				//求上传图片高宽
				$imginfo = getimagesize($file_path);
				$width = $imginfo[0];
				$height = $imginfo[1];
				//添加图片水印
				switch($ext_name) {
					case '.gif':
						$dst_im = imagecreatefromgif($file_path);
						break;
					case '.jpg':
						$dst_im = imagecreatefromjpeg($file_path);
						break;
					case '.png':
						$dst_im = imagecreatefrompng($file_path);
						break;
				}
				$src_im = imagecreatefrompng(MARK);
				//求水印图片高宽
				$src_imginfo = getimagesize(MARK);
				$src_width = $src_imginfo[0];
				$src_height = $src_imginfo[1];
				//求出水印图片的实际生成位置
				$src_x = $width - $src_width - 10;
				$src_y = $height - $src_height - 10;
				//新建一个真彩色图像
				$nimage = imagecreatetruecolor($width, $height);
				//拷贝上传图片到真彩图像
				imagecopy($nimage, $dst_im, 0, 0, 0, 0, $width, $height);
				//按坐标位置拷贝水印图片到真彩图像上
				imagecopy($nimage, $src_im, $src_x, $src_y, 0, 0, $src_width, $src_height);
				//分情况输出生成后的水印图片
				switch($ext_name) {
					case '.gif':
						imagegif($nimage, $file_path);
						break;
					case '.jpg':
						imagejpeg($nimage, $file_path);
						break;
					case '.png':
						imagepng($nimage, $file_path);
						break;
				}
				//释放资源
				imagedestroy($dst_im);
				imagedestroy($src_im);
				unset($imginfo);
				unset($src_imginfo);
				//移动生成后的图片
				@move_uploaded_file($file_path, ROOT_PATH.UPDIR . $file_path);
			}
		}

		/**
		 *  中文截取2，单字节截取模式
		 * @access public
		 * @param string $str  需要截取的字符串
		 * @param int $slen  截取的长度
		 * @param int $startdd  开始标记处
		 * @return string
		 */
		static public function cn_substr($str, $slen, $startdd=0){
			$cfg_soft_lang = PAGECHARSET;
			if($cfg_soft_lang=='utf-8') {
				return self::cn_substr_utf8($str, $slen, $startdd);
			}
			$restr = '';
			$c = '';
			$str_len = strlen($str);
			if($str_len < $startdd+1) {
				return '';
			}
			if($str_len < $startdd + $slen || $slen==0) {
				$slen = $str_len - $startdd;
			}
			$enddd = $startdd + $slen - 1;
			for($i=0;$i<$str_len;$i++) {
				if($startdd==0) {
					$restr .= $c;
				} elseif($i > $startdd) {
					$restr .= $c;
				}
				if(ord($str[$i])>0x80) {
					if($str_len>$i+1) {
						$c = $str[$i].$str[$i+1];
					}
					$i++;
				} else {
					$c = $str[$i];
				}
				if($i >= $enddd) {
					if(strlen($restr)+strlen($c)>$slen) {
						break;
					} else {
						$restr .= $c;
						break;
					}
				}
			}
			return $restr;
		}

		/**
		 *  utf-8中文截取，单字节截取模式
		 *
		 * @access public
		 * @param string $str 需要截取的字符串
		 * @param int $slen 截取的长度
		 * @param int $startdd 开始标记处
		 * @return string
		 */
		static public function cn_substr_utf8($str, $length, $start=0) {
			if(strlen($str) < $start+1) {
				return '';
			}
			preg_match_all("/./su", $str, $ar);
			$str = '';
			$tstr = '';
			//为了兼容mysql4.1以下版本,与数据库varchar一致,这里使用按字节截取
			for($i=0; isset($ar[0][$i]); $i++) {
				if(strlen($tstr) < $start) {
					$tstr .= $ar[0][$i];
				} else {
					if(strlen($str) < $length + strlen($ar[0][$i]) ) {
						$str .= $ar[0][$i];
					} else {
						break;
					}
				}
			}
			return $str;
		}

		/**
		 * 删除图片，根据图片ID
		 * @param int $image_id
		 */
		static function delPicByImageId($image_id) {
			$db_name = PREFIX . 'images i';
			$m = new Model();
			$data = $m->getOne($db_name, "i.id={$image_id}", "i.path as p, i.big_img as b, i.small_img as s");
			foreach ($data as $v) {
				@self::delFile(ROOT_PATH . $v['p']);
				@self::delFile(ROOT_PATH . $v['b']);
				@self::delFile(ROOT_PATH . $v['s']);
			}
			$m->del(PREFIX . 'images', "id={$image_id}");
			unset($m);
		}

		/**
		 * 图片等比例缩放
		 * @param resource $im    新建图片资源(imagecreatefromjpeg/imagecreatefrompng/imagecreatefromgif)
		 * @param int $maxwidth   生成图像宽
		 * @param int $maxheight  生成图像高
		 * @param string $name    生成图像名称
		 * @param string $filetype文件类型(.jpg/.gif/.png)
		 */
		static public function resizeImage($im, $maxwidth, $maxheight, $name, $filetype) {
			$pic_width = imagesx($im);
			$pic_height = imagesy($im);
			if(($maxwidth && $pic_width > $maxwidth) || ($maxheight && $pic_height > $maxheight)) {
				if($maxwidth && $pic_width>$maxwidth) {
					$widthratio = $maxwidth/$pic_width;
					$resizewidth_tag = true;
				}
				if($maxheight && $pic_height>$maxheight) {
					$heightratio = $maxheight/$pic_height;
					$resizeheight_tag = true;
				}
				if($resizewidth_tag && $resizeheight_tag) {
					if($widthratio<$heightratio)
						$ratio = $widthratio;
					else
						$ratio = $heightratio;
				}
				if($resizewidth_tag && !$resizeheight_tag)
					$ratio = $widthratio;
				if($resizeheight_tag && !$resizewidth_tag)
					$ratio = $heightratio;
				$newwidth = $pic_width * $ratio;
				$newheight = $pic_height * $ratio;
				if(function_exists("imagecopyresampled")) {
					$newim = imagecreatetruecolor($newwidth,$newheight);
					imagecopyresampled($newim,$im,0,0,0,0,$newwidth,$newheight,$pic_width,$pic_height);
				} else {
					$newim = imagecreate($newwidth,$newheight);
					imagecopyresized($newim,$im,0,0,0,0,$newwidth,$newheight,$pic_width,$pic_height);
				}
				$name = $name.$filetype;
				imagejpeg($newim,$name);
				imagedestroy($newim);
			} else {
				$name = $name.$filetype;
				imagejpeg($im,$name);
			}
		}

		/**
		 * 下载文件
		 * @param string $file_path 绝对路径
		 */
		static public function downFile($file_path) {
			//判断文件是否存在
			$file_path = iconv('utf-8', 'gb2312', $file_path); //对可能出现的中文名称进行转码
			if (!file_exists($file_path)) {
				exit('文件不存在！');
			}
			$file_name = basename($file_path); //获取文件名称
			$file_size = filesize($file_path); //获取文件大小
			$fp = fopen($file_path, 'r'); //以只读的方式打开文件
			header("Content-type: application/octet-stream");
			header("Accept-Ranges: bytes");
			header("Accept-Length: {$file_size}");
			header("Content-Disposition: attachment;filename={$file_name}");
			$buffer = 1024;
			$file_count = 0;
			//判断文件是否结束
			while (!feof($fp) && ($file_size-$file_count>0)) {
				$file_data = fread($fp, $buffer);
				$file_count += $buffer;
				echo $file_data;
			}
			fclose($fp); //关闭文件
		}
	}