text: 
      /*
   * Copyright  2018 Linkel Technology Co., Ltd, Beijing
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BA SIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  class Shell{
          
          shellCmd(cmd,callbackfunc){
              var exec = require('child_process').exec;
              exec(cmd, function (err, stdout, stderr) {
                  callbackfunc(err, stdout, stderr);
              });
          }
  
          shellFile(filename,callbackfunc){
              var exec = require('child_process').execFile;
              exec(filename,{encoding:'utf8'},function (err,stdout,stderr){
                  callbackfunc(err, stdout, stderr);
              });
          }
      }
  
      exports.Shell = Shell;