code: function execDirRecursive(path, options) {
      var self = this;
      var results = [];
      walkDirRecursive(path, function (pth) {
        var result = self.execDir(pth, options);
        results.push(result);
      });
  
      return results;
    }
docs: Recursively executes `execDir`.
  For use with `ls -R`.
  
  @param {String} path
  @param {Object} options
  @return {Array} results
  @api private