multisite cron for wordpress

wp-multisite-cron.php

<?php
/**
 * Multisite Cron task. Hits the cron url for all enabled blogs so scheduled tasks function designed.
 * @see http://www.lucasrolff.com/wordpress/why-wp-cron-sucks/
 * 
 * Add this to your /etc/crontab file. Runs once per hour. Outputs log.
 * 1 * * * * wget -q -O - "http://mydomain.com/wp-cron-multisite.php?doing_wp_cron >> /tmp/wp-cron.log
 */
require('./wp-load.php');
//increase memory for this process.
ini_set('memory_limit','512M');

global $wpdb;
//fetch list of active blogs
$sql = $wpdb->prepare("SELECT domain, path FROM $wpdb->blogs WHERE archived = '0' and deleted = 0", '');
$blogs = $wpdb->get_results($sql);

foreach($blogs as $blog) {
	set_time_limit(180); //3min per site max.
	$command = "http://" . $blog->domain . ($blog->path ? $blog->path : '/') . 'wp-cron.php?doing_wp_cron';
	//only run if load is low.
	$load = sys_getloadavg();
	if ($load[0] <= 1.0) {
		echo 'Running cron for ' . $blog->path . date('Y-m-d h:i:s') ."\n";
		$ch = curl_init($command);
		$rc = curl_setopt($ch, CURLOPT_RETURNTRANSFER, FALSE);
		$rc = curl_exec($ch);
		curl_close($ch);
	}else{
		echo 'Too busy. Skipped ' . $blog->path . date('Y-m-d h:i:s') . "\n";
	}
}