WordPress默认自带的robots.txt文件设置在哪里

WordPress 5.2网站通过Robots协议告诉搜索引擎哪些页面可以抓取，哪些页面不能抓取，robots默认都是放在网站根目录。刚建好的WordPress网站，打开robots.txt是能访问的，但是在网站目录却找不到任何robots.txt文件，其实默认的robots文件放在wp-includes/functions.php中，通过搜索robots大概在1466行可进行修改

function do_robots() {
	header( 'Content-Type: text/plain; charset=utf-8' );

	/**
	 * Fires when displaying the robots.txt file.
	 *
	 * @since 2.1.0
	 */
	do_action( 'do_robotstxt' );

	$output = "User-agent: *\n";
	$public = get_option( 'blog_public' );
	if ( '0' == $public ) {
		$output .= "Disallow: /\n";
	} else {
		$site_url = parse_url( site_url() );
		$path     = ( ! empty( $site_url['path'] ) ) ? $site_url['path'] : '';
		$output  .= "Disallow: $path/wp-admin/\n";
		$output  .= "Allow: $path/wp-admin/admin-ajax.php\n";
	}

	/**
	 * Filters the robots.txt output.
	 *
	 * @since 3.0.0
	 *
	 * @param string $output Robots.txt output.
	 * @param bool   $public Whether the site is considered "public".
	 */
	echo apply_filters( 'robots_txt', $output, $public );
}