uninstall.php

<?php
if ( !defined('ABSPATH') && !defined('WP_UNINSTALL_PLUGIN') ) {
	// Make sure not to call this file directly
	exit();
} else {
	// Is this WordPressMU or not?
	if ( isset($wpmu_version) || strpos($wp_version, 'wordpress-mu') ) {
		$s2_mu = true;
	}
	if ( function_exists('is_multisite') && is_multisite() ) {
		$s2_mu = true;
	}

	if ( $s2_mu ) {
		global $wpdb;
		$blogs = $wpdb->get_col("SELECT blog_id FROM {$wpdb->blogs}");
		foreach ( $blogs as $blog ) {
			switch_to_blog($blog);
			s2_uninstall();
			restore_current_blog();
		}
	} else {
		s2_uninstall();
	}
}
function s2_uninstall() {
	global $wpdb;
	// get name of subscribe2 table
	$public = $wpdb->prefix . "subscribe2";
	// delete entry from wp_options table
	delete_option('subscribe2_options');
	// delete legacy entry from wp-options table
	delete_option('s2_future_posts');
	// remove and scheduled events
	wp_clear_scheduled_hook('s2_digest_cron');
	// delete usermeta data for registered users
	// use LIKE and % wildcard as meta_key names are prepended on WPMU
	// and s2_cat is appended with category ID integer
	$wpdb->query("DELETE from $wpdb->usermeta WHERE meta_key LIKE '%s2_cat%'");
	$wpdb->query("DELETE from $wpdb->usermeta WHERE meta_key LIKE '%s2_subscribed'");
	$wpdb->query("DELETE from $wpdb->usermeta WHERE meta_key LIKE '%s2_format'");
	$wpdb->query("DELETE from $wpdb->usermeta WHERE meta_key LIKE '%s2_autosub'");
	// delete any postmeta data that supressed notifications
	$wpdb->query("DELETE from $wpdb->postmeta WHERE meta_key = 's2mail'");

	// drop the subscribe2 table
	$sql = "DROP TABLE IF EXISTS `" . $public . "`";
	$wpdb->query($sql);
} // end s2_uninstall()
?>