T5 Comment List Shortcode

shortcode-get-comments.php

<?php
/**
 * Plugin Name: T5 Comment List Shortcode
 * Description: Use [listcomments post_id="NUMBER"] to list comments from another post.
 * Plugin URI:
 * Version:     2013.01.10
 * Author:      Thomas Scholz
 * Author URI:  http://toscho.de
 * Licence:     MIT
 * License URI: http://opensource.org/licenses/MIT
 */

add_shortcode( 'listcomments', 't5_list_comments' );

function t5_list_comments( $atts, $content = '' )
{
	'' !== $content && $content = wpautop( do_shortcode( $content ) );

	if ( ! isset ( $atts['post_id'] ) )
		return 'Please pass an argument for "post_id"';

	if ( ! $comments = get_comments( $atts ) )
		return 'No comments found for post ID '. esc_html( $atts['post_id'] );

	$out = $content . '<ul class="t5-comment-list">';
	foreach ( $comments as $comment )
	{
		$out .= sprintf(
			'<li>%1$s%2$s</li>',
			get_comment_author_link( $comment->comment_ID ),
			wpautop( $comment->comment_content )
		);
	}

	return $out . '</ul>';
}