Migrate php session from file to redis|memcache

migrate_sessions.php

#!/usr/bin/env php
<?php

$host = '127.0.0.1';
$port = null;
$oldPrefix = 'sess_';
$newPrefix = 'sess_';
$sessionDir = '/var/lib/php/session/';

$m = new \Redis();
$m->connect($host, $port);

// $m = new \Memcached();
// $m->addServer($host, $port);

$sessions = scandir($sessionDir);
if (!$sessions) {
    die('nothing to migrate');
}
foreach ($sessions as $s) {
    if (in_array($s, ['.', '..'])) {
        continue;
    }
    $sessionName = str_replace($oldPrefix, '', $s);
    $sessionContents = file_get_contents($sessionDir.$s);

    if (!$m->set($newPrefix.$sessionName, $sessionContents)) {
        die(sprintf('Could not migrate session %s'.PHP_EOL, $newPrefix.$sessionName));
    }
    echo '.';
}
die(PHP_EOL);