Retwis ported to modern Redis data types.

The example (and related documentation at redis.io) was not updated for
5 years. Redis had no sorted sets and hashes when the original code was
written (!). An update was really needed.

We also use a modern PHP client now: Predis. A copy is shipped within
this repository to make life easier to newcomers trying Redis for the
first time via this example.

Predis/Command/ServerClient.php

@@ -0,0 +1,73 @@
+<?php
+
+/*
+ * This file is part of the Predis package.
+ *
+ * (c) Daniele Alessandri <suppakilla@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Predis\Command;
+
+/**
+ * @link http://redis.io/commands/client-list
+ * @link http://redis.io/commands/client-kill
+ * @link http://redis.io/commands/client-getname
+ * @link http://redis.io/commands/client-setname
+ * @author Daniele Alessandri <suppakilla@gmail.com>
+ */
+class ServerClient extends AbstractCommand
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function getId()
+    {
+        return 'CLIENT';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function parseResponse($data)
+    {
+        $args = array_change_key_case($this->getArguments(), CASE_UPPER);
+
+        switch (strtoupper($args[0])) {
+            case 'LIST':
+                return $this->parseClientList($data);
+            case 'KILL':
+            case 'GETNAME':
+            case 'SETNAME':
+            default:
+                return $data;
+        }
+    }
+
+    /**
+     * Parses the reply buffer and returns the list of clients returned by
+     * the CLIENT LIST command.
+     *
+     * @param  string $data Reply buffer
+     * @return array
+     */
+    protected function parseClientList($data)
+    {
+        $clients = array();
+
+        foreach (explode("\n", $data, -1) as $clientData) {
+            $client = array();
+
+            foreach (explode(' ', $clientData) as $kv) {
+                @list($k, $v) = explode('=', $kv);
+                $client[$k] = $v;
+            }
+
+            $clients[] = $client;
+        }
+
+        return $clients;
+    }
+}