Stomp console chat client

chat.php

<?php

$author = trim(`whoami`);
$pid    = pcntl_fork();
if ($pid === 0) {
    // Child process here
    $stomp = new Stomp();
    $stomp->subscribe('/topic/Chat');
    while (true) {
        $frame = $stomp->readFrame();
        if ($frame) {
            $packet = json_decode($frame->body, true);
            echo date('H:m:i '), $packet['author'], ': ', $packet['text'], PHP_EOL;
            $stomp->ack($frame);
        }
    }
} elseif ($pid !== -1) {
    echo "Simple chat client, please type 'q' to exit or type anything and press enter", PHP_EOL;
    $stomp = new Stomp();
    while (true) {
        $line = trim(fgets(STDIN));
        if ($line=='q') {
            break;
        }
        $message = json_encode(array(
            'text'   => $line,
            'author' => $author,
        ));
        $stomp->send('/topic/Chat', $message);
    }
    posix_kill($pid, 9);
}