Flush PHP memcacheD cache in WordPress - Flushes PHP memcached cache upon publish_post action. By clearing the opcode cache in memory you immediately can see a new or changed post

saotn-flush-memcached.php

<?php
/**
 * Plugin Name: Flush MemcacheD cache
 * Plugin URI: https://www.saotn.org/
 * Donate URI: https://www.paypal.me/jreilink
 * Description: Flushes PHP memcached cache upon publish_post action. By clearing the opcode cache in memory you immediately can see a new or changed post. Use as a Must-Use Plugin.
 * Network: True
 * Version: 1.2
 * Author: Jan Reilink
 * Author URI: https://www.saotn.org
 * License: GPLv2
 */

require_once( ABSPATH .'/wp-config.php' );
function manual_clear_memcached_cache() {
	if( class_exists( 'Memcached' ) ) {
		/* $memcached_servers comes from the plugins:
		 * https://wordpress.org/plugins/memcached/, or
		 * https://wordpress.org/plugins/memcached-is-your-friend/
		 *
		 * change this if you're using something else, or add your Unix socket path like:
		 * https://gist.github.com/Digiover/f3a30849f621cdb97e3346b300711e74
		 */
		global $memcached_servers;
		if( isset($memcached_servers)) {
			list( $socket, $port ) = explode( ":", $memcached_servers["default"][0] );
			$m = new Memcached();
			$m->addServer( $socket, $port);
			if ( false === $m->flush() ) {
				// result is logged to WP Debug log
				error_log( 'After post publish: Clearing Memcached failed.' );
				return false;
			}
			else {
				// result is logged to WP Debug log
				error_log( 'After post publish: Memcached flushed' );
				return true;
			}
		}
	}
}
add_action( 'publish_post', 'manual_clear_memcached_cache', 10, 2 );

// fmd = flush memcached
add_filter( 'plugin_row_meta', 'fmd_plugin_row_meta', 10, 2 );
function fmd_plugin_row_meta($links, $file) {
    if ( !preg_match('/saotn-flush-memcached.php$/', $file ) ) {
      return $links;
    }

    $links[] = sprintf(
      '<a target="_blank" href="https://paypal.me/jreilink" title="Donate to Jan Reilink / Sysadmins of the North">%s</a>',
      __( 'Donate' )
    );
    return $links;
}

?>