protected function updateAlias() {
    $alias_info = $this->getAliasInfo();
    $new_contents = str_replace($alias_info['alias'], $alias_info['canonical_alias'], $alias_info['contents']);
    $bytes = file_put_contents($alias_info['config_file'], $new_contents);
    if (!$bytes) {
      throw new BltException("Could not update BLT alias in {$alias_info['config_file']}.");
    }

    $this->say("<info>The <comment>blt</comment> alias was updated in {$alias_info['config_file']}");
    $this->say("Execute <comment>source {$alias_info['config_file']}</comment> to update your terminal session.");
    $this->say("You may then execute <comment>blt</comment> commands.");
  }