写文件

        //写配置
        $str    = "<?php 
";
//        $str .= "unset($web_site);
";
//        $str .= "$web_site          =  array();
";

        $str   .= "$config['web_site'] = array ( 
";
        $str   .= "  'webopen'=>1, 
";
        $str   .= "  'webopens'=>2, 
";
        $str   .= "  'other_params'=>'{"is_reg":"1","reg_site":"http://www.qq.com"}', 
";
        $str   .= "); 
";

        $this->load->helpers('file_helper');

        if(!write_file(APPPATH."config/config_website.php",$str.'?>')){ //写入缓存失败
            ereturn("缓存文件写入失败！请先设/website.php文件权限为：0777");
        }