WordPress/wp-includes/feed.php

<?php

function get_bloginfo_rss($show = '') {
	$info = strip_tags(get_bloginfo($show));
	return apply_filters('bloginfo_rss', convert_chars($info));
}

function bloginfo_rss($show = '') {
	echo get_bloginfo_rss($show);
}

function get_the_title_rss() {
	$title = get_the_title();
	$title = apply_filters('the_title', $title);
	$title = apply_filters('the_title_rss', $title);
	return $title;
}

function the_title_rss() {
	echo get_the_title_rss();
}

function the_content_rss($more_link_text='(more...)', $stripteaser=0, $more_file='', $cut = 0, $encode_html = 0) {
	$content = get_the_content($more_link_text, $stripteaser, $more_file);
	$content = apply_filters('the_content_rss', $content);
	if ( $cut && !$encode_html )
		$encode_html = 2;
	if ( 1== $encode_html ) {
		$content = wp_specialchars($content);
		$cut = 0;
	} elseif ( 0 == $encode_html ) {
		$content = make_url_footnote($content);
	} elseif ( 2 == $encode_html ) {
		$content = strip_tags($content);
	}
	if ( $cut ) {
		$blah = explode(' ', $content);
		if ( count($blah) > $cut ) {
			$k = $cut;
			$use_dotdotdot = 1;
		} else {
			$k = count($blah);
			$use_dotdotdot = 0;
		}
		for ( $i=0; $i<$k; $i++ ) {
			$excerpt .= $blah[$i].' ';
		}
		$excerpt .= ($use_dotdotdot) ? '...' : '';
		$content = $excerpt;
	}
	$content = str_replace(']]>', ']]&gt;', $content);
	echo $content;
}

function the_excerpt_rss() {
	$output = get_the_excerpt(true);
	echo apply_filters('the_excerpt_rss', $output);
}

function permalink_single_rss($file = '') {
	echo get_permalink();
}

function comment_link() {
	echo get_comment_link();
}

function get_comment_author_rss() {
	return apply_filters('comment_author_rss', get_comment_author() );
}
function comment_author_rss() {
	echo get_comment_author_rss();
}

function comment_text_rss() {
	$comment_text = get_comment_text();
	$comment_text = apply_filters('comment_text_rss', $comment_text);
	echo $comment_text;
}

function comments_rss_link($link_text = 'Comments RSS', $commentsrssfilename = '') {
	$url = comments_rss($commentsrssfilename);
	echo "<a href='$url'>$link_text</a>";
}

function comments_rss($commentsrssfilename = '') {
	global $id;

	if ( '' != get_option('permalink_structure') )
		$url = trailingslashit( get_permalink() ) . 'feed/';
	else
		$url = get_option('home') . "/$commentsrssfilename?feed=rss2&amp;p=$id";

	return apply_filters('post_comments_feed_link', $url);
}

function get_author_rss_link($echo = false, $author_id, $author_nicename) {
	$auth_ID = $author_id;
	$permalink_structure = get_option('permalink_structure');

	if ( '' == $permalink_structure ) {
		$link = get_option('home') . '?feed=rss2&amp;author=' . $author_id;
	} else {
		$link = get_author_posts_url($author_id, $author_nicename);
		$link = $link . "feed/";
	}

	$link = apply_filters('author_feed_link', $link);

	if ( $echo )
		echo $link;
	return $link;
}

function get_category_rss_link($echo = false, $cat_ID, $category_nicename) {
	$permalink_structure = get_option('permalink_structure');

	if ( '' == $permalink_structure ) {
		$link = get_option('home') . '?feed=rss2&amp;cat=' . $cat_ID;
	} else {
		$link = get_category_link($cat_ID);
		$link = $link . "feed/";
	}

	$link = apply_filters('category_feed_link', $link);

	if ( $echo )
		echo $link;
	return $link;
}

function get_the_category_rss($type = 'rss') {
	$categories = get_the_category();
	$the_list = '';
	foreach ( (array) $categories as $category ) {
		$category->cat_name = convert_chars($category->cat_name);
		if ( 'rdf' == $type )
			$the_list .= "\n\t\t<dc:subject>$category->cat_name</dc:subject>\n";
		else
			$the_list .= "\n\t\t<category>$category->cat_name</category>\n";
	}
	return apply_filters('the_category_rss', $the_list, $type);
}

function the_category_rss($type = 'rss') {
	echo get_the_category_rss($type);
}

function rss_enclosure() {
	global $id, $post;
	if ( !empty($post->post_password) && ($_COOKIE['wp-postpass_'.COOKIEHASH] != $post->post_password) )
		return;

	$custom_fields = get_post_custom();
	if ( is_array($custom_fields) ) {
		while ( list($key, $val) = each($custom_fields) ) { 
			if ( $key == 'enclosure' ) {
				if ( is_array($val) ) {
					foreach ( (array) $val as $enc ) {
						$enclosure = split( "\n", $enc );
						print "<enclosure url='".trim( htmlspecialchars($enclosure[ 0 ]) )."' length='".trim( $enclosure[ 1 ] )."' type='".trim( $enclosure[ 2 ] )."'/>\n";
					}
				}
			}
		}
	}
}

?>