code: function run_ktserver(options, callback) {
  
    try {
  
      var options = options || {};
      var args = [];
      if (options.host) {
        args.push('-host');
        args.push(options.host);
      }
      if (options.port) {
        args.push('-port');
        args.push(options.port);
      }
  
      var ktserver = child_process.spawn('ktserver', args);
      if (!ktserver) {
        callback({
          message: 'failed create ktserver child process',
        });
        return;
      }
  
      ktserver.on('exit', function (code) {
        ktserver.stdin.end();
      });
  
      callback(null, ktserver);
  
    } catch (e) {
      callback(e);
    }
  }
docs: common(s)