A HitchHackers guide through WordPress

Source code

function check_comment($author, $email, $url, $comment, $user_ip, $user_agent, $comment_type) {

	global $wpdb;



	if ( 1 == get_option('comment_moderation') )

		return false; // If moderation is set to manual



	$comment = apply_filters( 'comment_text', $comment );



	// Check # of external links

	if ( $max_links = get_option( 'comment_max_links' ) ) {

		$num_links = preg_match_all( '/<a [^>]*href/i', $comment, $out );

		$num_links = apply_filters( 'comment_max_links_url', $num_links, $url ); // provide for counting of $url as a link

		if ( $num_links >= $max_links )

			return false;

	}



	$mod_keys = trim(get_option('moderation_keys'));

	if ( !empty($mod_keys) ) {

		$words = explode("\n", $mod_keys );



		foreach ( (array) $words as $word) {

			$word = trim($word);



			// Skip empty lines

			if ( empty($word) )

				continue;



			// Do some escaping magic so that '#' chars in the

			// spam words don't break things:

			$word = preg_quote($word, '#');



			$pattern = "#$word#i";

			if ( preg_match($pattern, $author) ) return false;

			if ( preg_match($pattern, $email) ) return false;

			if ( preg_match($pattern, $url) ) return false;

			if ( preg_match($pattern, $comment) ) return false;

			if ( preg_match($pattern, $user_ip) ) return false;

			if ( preg_match($pattern, $user_agent) ) return false;

		}

	}



	// Comment whitelisting:

	if ( 1 == get_option('comment_whitelist')) {

		if ( 'trackback' != $comment_type && 'pingback' != $comment_type && $author != '' && $email != '' ) {

			// expected_slashed ($author, $email)

			$ok_to_comment = $wpdb->get_var("SELECT comment_approved FROM $wpdb->comments WHERE comment_author = '$author' AND comment_author_email = '$email' and comment_approved = '1' LIMIT 1");

			if ( ( 1 == $ok_to_comment ) &&

				( empty($mod_keys) || false === strpos( $email, $mod_keys) ) )

					return true;

			else

				return false;

		} else {

			return false;

		}

	}

	return true;

}