This is a quick little script I wrote to use on my Mac for geektool. You can call this script from the command line with PHP and supply an rss feed URL on the command line and the script will parse it.

Examples:

dave@server:~$ php rss.php
Usage: php rss.php <rss feed URL> [# stories]

dave@server:~$ php rss.php http://www.daveeddy.com/feed/
Dave Eddy
>> GeekTool For Mac (revisited) (23 minutes ago)
>> Viridian 1.2 Released (1 week ago)
>> Introduction to Unix Tutorial (3 weeks ago)
>> RITLUG (3 weeks ago)
>> Ampache Now Playing WordPress… Now with Ajax/jQuery (1 month ago)

dave@server:~$ php rss.php http://www.daveeddy.com/feed/ 2 # only show 2 stories
Dave Eddy
>> GeekTool For Mac (revisited) (23 minutes ago)
>> Viridian 1.2 Released (1 week ago)

Download

rss.php.zip

The code

<?php
/**
 * Copyright (C) 2011 Dave Eddy <dave@daveeddy.com>
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2, as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranties of
 * MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
 * PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * rss.php
 * Parse RSS feeds supplied over the command line
 * Written by Dave Eddy <dave@daveeddy.com>
 *
 * Usage Example: php rss.php http://www.daveeddy.com/feed/
 */

/* Config Variables */
date_default_timezone_set('America/New_York'); // set this to your locale

/* No need to edit below this line */

$site    = $_SERVER['argv'][1];
$stories = $_SERVER['argv'][2];

/**
 * Converts a Unix time stamp to how long ago it was relative to now
 * Taken from stackoverflow
 * http://stackoverflow.com/questions/2981602/twitter-rss-pubdate-format
 */
function how_long_ago($unixTime) {
    $chunks = array(
        array(60 * 60 * 24 * 365 , 'year'),
        array(60 * 60 * 24 * 30 , 'month'),
        array(60 * 60 * 24 * 7, 'week'),
        array(60 * 60 * 24 , 'day'),
        array(60 * 60 , 'hour'),
        array(60 , 'minute'),
    );
    $today = time();
    $since = $today - $unixTime;
    for ($i = 0, $j = count($chunks); $i < $j; $i++) {
        $seconds = $chunks[$i][0];
        $name = $chunks[$i][1];
        if (($count = floor($since / $seconds)) != 0) {
            break;
        }
    }
    return $count == 1 ? '1 '.$name : "$count {$name}s";
}

if (!isset($site)) {
	die('Usage: php '.basename(__FILE__).' <rss feed URL> [# stories]'."\n");
}
if (!isset($stories)) {
	$stories = 5;
}

$dom = New DomDocument();
if (!@$dom->load($site)) {
	exit(1); // exit with 1 if it failed to load
}

$items = $dom->getElementsByTagName('item');

echo $dom->getElementsByTagName('title')->item(0)->nodeValue."\n";
for ($i=0;$i<$stories;$i++) {
	if ($i >= $items->length) {
		continue; // you wanted more stories than the RSS had
	}
	$item = $items->item($i);
	$age = how_long_ago(strtotime($item->getElementsByTagName('pubDate')->item(0)->nodeValue));
	echo ">> " . $item->getElementsByTagName('title')->item(0)->nodeValue." ($age ago)\n";
	// uncomment to display the content section of the feed
	//echo $item->getElementsByTagName('description')->item(0)->nodeValue."\n";
}