Terminal Chat Server

client.php

<?php
// Client script
$socket = stream_socket_client("tcp://localhost:8000", $errorNumber, $errorMessage);

if (!$socket) {
    echo "{$errorMessage} ({$errorNumber})<br />\n";
} else {
    stream_set_blocking($socket, false);

    $username = readline("Enter your username: ");
    fwrite($socket, trim($username) . "\n");

    while (true) {
        $read = array(STDIN, $socket);
        $write = null;
        $except = null;

        if (stream_select($read, $write, $except, 0, 200000)) {
            if (in_array(STDIN, $read, true)) {
                $input = fgets(STDIN);

                if ($input === false || trim($input) === '') {
                    continue;
                }

                if (trim($input) === '/quit') {
                    fwrite($socket, trim($input) . "\n");
                    break;
                }

                fwrite($socket, trim($input) . "\n");
            }

            if (in_array($socket, $read, true)) {
                $message = fgets($socket);

                if ($message === false) {
                    echo "Server disconnected\n";
                    break;
                }

                echo $message;
            }
        }
    }

    fclose($socket);
}

server.php

<?php
// Server script

$server = stream_socket_server("tcp://localhost:8000", $errorNumber, $errorMessage);

if (!$server) {
    echo "{$errorMessage} ({$errorNumber})<br />\n";
} else {
    $clients = array();
    $usernames = array();

    while (true) {
        $read = array_merge(array($server), $clients);
        $write = null;
        $except = null;

        if (stream_select($read, $write, $except, 0, 200000)) {
            if (in_array($server, $read, true)) {
                $clients[] = $client = stream_socket_accept($server);

                $username = trim(fgets($client));
                $usernames[(int)$client] = $username;

                echo $username . " connected\n";

                $key = array_search($server, $read, true);
                unset($read[$key]);

                fwrite($client, "Welcome to the chat server, {$username}\n");
            }

            foreach ($read as $client) {
                $message = fgets($client);

                if ($message === false || feof($client) || trim($message) === '/quit') {
                    echo $usernames[(int)$client] . " disconnected\n";

                    $key = array_search($client, $clients, true);
                    unset($clients[$key], $usernames[(int)$client]);
                    fclose($client);
                } else {
                    foreach ($clients as $other_client) {
                        if ($other_client !== $client) {
                            fwrite($other_client, $usernames[(int)$client] . ": " . $message);
                        }
                    }
                }
            }
        }
    }

    fclose($server);
}