Purge excess sessions caused by increased `gc_maxlifetime` and https://github.com/clockworkgeek/Magento-Remember-Me

forgetSessions.php

#!/usr/bin/env php
<?php
/**
 * Place this script in your Magento root and optionally set the executable flag.
 * 
 *   chmod +x forgetSessions.php
 * 
 * For a dry run set "DEBUG = true" below and watch all the session names go by.
 * For cron use consider setting "OUTPUT = false" to suppress success message,
 * only errors will be reported.
 */

const OUTPUT = true;
const DEBUG = false;

// make sure path is correct for your store
// this assumes script is in store root
define('SESSION_PATH', __DIR__ . '/var/session');

// this should match PHP's native naming
// change only if server is configured to name differently
define('SESSION_PATTERN', 'sess_*');

// only process files older than this time
// 3600 seconds = 1 hour
define('EXPIRY_LIMIT', time() - 3600);

// no time limit because this might be a big job
set_time_limit(0);

// this loads user data, writes a cookie, etc.
// must restore afterwards or data will be damaged
session_start();
$preserved_sess = $_SESSION;

// declare plain text for browser use
// CLI is unaffected
if (! headers_sent()) {
    header('Content-Type: text/plain');
}

// useful stats
$count_sess = 0;
$count_unlinks = 0;

// iterate instead of glob in case there are a lot of files to scan
$dir = new DirectoryIterator(SESSION_PATH);
foreach ($dir as $file) {
    // ignore sub-directories
    if ($file->isDir()) continue;
    // reject non-session files
    if (! fnmatch(SESSION_PATTERN, $file->getFilename())) continue;
    // reject recently modified files
    if (EXPIRY_LIMIT < $file->getMTime()) {
        if (DEBUG) echo $file->getFilename(), ' - Skip', PHP_EOL;
        continue;
    }

    // overwrite $_SESSION var
    if (session_decode(file_get_contents($file->getPathname()))) {
        $count_sess++;
        // suppress null pointer error in case key is not set
        $rememberme = @$_SESSION['rememberme'];

        if ($rememberme) {
            if (! DEBUG) unlink($file->getFilename());
            $count_unlinks++;
        }
        if (DEBUG) echo $file->getFilename(), ($rememberme ? ' - Remember' : ' - Forget' ), PHP_EOL;
    }
}

// be responsible in case user has a real session to protect
if (function_exists('session_abort')) {
    session_abort();
}
else {
    $_SESSION = $preserved_sess;
}

if (OUTPUT) {
    echo 'Sessions read: ', $count_sess, PHP_EOL;
    echo 'Sessions removed: ', $count_unlinks, PHP_EOL;
}