css update class implemented by php

/**css update class, update the version of the image in the css file
* Date: 2013-02-05
* Author: fdipzone
* Ver: 1.1
* Edit: bbs.it-home.org
* Func:
* update() ;
*
* Ver: 1.1 Added search_child parameter to traverse subfolders
*/

class CSSUpdate{
    private $csstmpl_path = null;
    private $css_path = null;
    private $replacetags = array();
    private $search_child = false;
    private $convert_num = 0;
    private $is_ready = 0;

    /**Initialization
 * @param String $csstmpl_path css template path
 * @param String $css_path css target path
 * @param Array $replacetags Image type to be replaced
 * @param boolean $search_child Whether to traverse subfolders, default false
*/
    public function __construct($csstmpl_path, $css_path, $replacetags=array(), $search_child=false){
        if(!is_dir($csstmpl_path) || !is_dir($css_path) || !$replacetags){
            $this->is_ready = 0;
        }else{
            $this->csstmpl_path = $csstmpl_path;
            $this->css_path = $css_path;
            $this->replacetags = $replacetags;
            $this->search_child = $search_child;
            $this->is_ready = 1;
        }
    }

    /**Update css file*/
    public function update(){
        if($this->is_ready==0){
            $this->response('csstmpl or csspath or replacetags error');
            return '';
        }
        $this->traversing($this->csstmpl_path);
        $this->response('covert num:'.$this->convert_num);
    }

    /**Traverse folders
 * @param String $path file path
*/
    private function traversing($path){
        $handle = opendir($path);
        while(($file=readdir($handle))!==false){
            if($file!='..' && $file!='.'){
                $curfile = $path.'/'.$file;

                if(is_dir($curfile)){   // folder
                    if($this->search_child){    // 需要遍历子文件夹
                        $this->traversing($curfile);
                    }
                }elseif($this->checkExt($curfile)){ // css file
                    $dfile = str_replace($this->csstmpl_path, $this->css_path, $curfile);
                    $this->create($curfile, $dfile);
                    $this->response($curfile.' convert to '.$dfile.' success');
                    $this->convert_num ++;
                }
            }
        }
        closedir($handle);
    }

    /**Check file suffix*/
    private function checkExt($file){
        $name = basename($file);
        $namefrag = explode('.', $name);
        if(count($namefrag)>=2){
            if(strtolower($namefrag[count($namefrag)-1])=='css'){ // css文件
                return true;
            }
        }
        return false;
    }

    /**Replace template content and write to csspath
 * @param String $tmplfile template file
 * @param String $dfile target file
*/
    private function create($tmplfile, $dfile){
        $css_content = file_get_contents($tmplfile);

        foreach($this->replacetags as $tag){
            $css_content = str_replace($tag, $tag."?".date('YmdHis'), $css_content);
        }

        if(!is_dir(dirname($dfile))){   // 生成目标路径
            mkdir(dirname($dfile), 0755, true);
        }

        file_put_contents($dfile, $css_content, true);
    }

    /**output*/
    private function response($content){
        echo $content."";
    }
}
?>

2，演示示例 demo.php

require_once "CSSUpdate.class.php";

define('ROOT_PATH', dirname(__FILE__));

$css_path = ROOT_PATH.'/css';
$csstmpl_path = ROOT_PATH.'/csstmpl';
$replacetags = array('.png', '.jpg', '.gif');

$cssobj = new CSSUpdate($csstmpl_path, $css_path, $replacetags);
$cssobj->update();
?>

附， php css更新类的源码下载地址。