wordpress-update_super_admins_access.php

<?
// this is to be put in a single site/plugin.. not network wide.
// if it's network wide it will run a `transient` for each site. which'd be ridiculous
// it only needs to run in a single site enviroment
add_action('init', 'update_super_admins_access');
function update_super_admins_access() {
	
	// since this is a big thing to do, we can run a test and see whats
	// going to happen before it does
	$test = false;
	
	// this is the scheduling feature, run only once a month.
	// I used transient because the API is eaiser and the load of the function isn't demanding. 
	// I know transient is for cacheing but as shown it can be used to schedule aswell. 
	// wp_schedule_event() cron events would be the best and cleanest solution. I reccomend doing it that way.
	// if you're ontop of your code, an if statment like if (isset($_GET['update_super_admins'])) 
	// would be good enough to run and fire manually
	$cache = 60*60*24*30; 
	if ( false === ( $last = get_transient( 'update_super_admins_access' ) ) ) {
		
		// lets get all the super admins, and all the sites
		$superAdmins = get_super_admins();
		$allSites = wp_get_sites(
			array('deleted' => '0')
		);
		
		// and we'll store the test run in a simple array
		$dryrun = array();
		
		// cycle through each super admin 
		foreach ($superAdmins as $sAdmin) {
			
			// get the super admin details since the above was just slug
			$user = get_user_by('login',$sAdmin);
			$user_id = $user->ID;
			
			// k lets define the user, and prepare the list of sites
			$dryrun[$user->data->user_nicename] = array();
			
			// cycle through each site
			foreach ($allSites as $site) {
				
				// check if is already added or not
				if (!is_user_member_of_blog( $user_id, $site['blog_id'] )) {
					
					// record the site for the user to be added to
					$dryrun[$user->data->user_nicename][] = $site['path'];
					
					// and if we're not testing: go go go
					if (!$test) 
						add_user_to_blog( $site['blog_id'], $user_id, 'administrator' );
				}
			}
		}
		
		// if testing, just spit the array and some instructions
		if ($test) {
			echo "<pre>".print_r($dryrun,true)."</pre>";
			die('The above shows which users will be added to which sites. to actually run this, set `$test = false;`');
		} 
		// if we're actually running this, don't do it again until cache exp
		else {
			set_transient( 'update_super_admins_access', time(), $cache );
		}
	}
}
?>