Redis autocomplete using ZRANGEBYLEX

search.php

<?php

/**
 * Redis autocomplete using ZRANGEBYLEX command. 
 * Based on https://gist.github.com/antirez/11126283
 *
 * @see https://github.com/angyvolin/redis-autocomplete-demo for online demo.
 */

require __DIR__.'/vendor/autoload.php';

$client = new Predis\Client([
    'host' => '127.0.0.1',
    'port' => 6379,
    'database' => 15
]);

$term = $_GET['term'];
$items = $client->zrangebylex('kernel', "[$term", "[$term\xff", ['LIMIT', '0', '10']);

$id = 0;
$result = [];
foreach ($items as $item) {
    $result[] = ['id' => $id++, 'label' => $item];
}

echo json_encode($result);

See redis-autocomplete-demo for online demo app deployed to Heroku