function read_(cmd, path, successCallback) {
    if (!fs_) {
      return;
    }

    cwd_.getFile(path, {}, function(fileEntry) {
      fileEntry.file(function(file) {
        var reader = new FileReader();

        reader.onloadend = function(e) {
          successCallback(this.result);
        };

        reader.readAsText(file);
      }, errorHandler_);
    }, function(e) {
      if (e.code == FileError.INVALID_STATE_ERR) {
        output(cmd + ': ' + path + ': is a directory<br>');
      } else if (e.code == FileError.NOT_FOUND_ERR) {
        output(cmd + ': ' + path + ': No such file or directory<br>');
      }
    });
  }
Reads a file

@param {String} cmd The attempted command
@param {String} path The file path
@param {Function} successCallback Callback to pass the file reference