UDP server in PHP

<?php
$sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
if(!socket_bind($sock,0,$argv[1])){
    printMessage("Couldn't bind socket");
    exit;
}
socket_set_nonblock($sock);

$clients = array();

$clients = array($sock);

$c = array();

$wait=1;

$users = array();

while (true) {
    usleep($wait);
    // create a copy, so $clients doesn't get modified by socket_select()
    $read = array($sock);
    $write = array();
    $except = NULL;
    $buf="";

    // get a list of all the clients that have data to be read from
    // if there are no clients with data, go to next iteration
    if (socket_select($read, $write, $except, 0) < 1){
        $wait = 100;
        continue;
     }
     $wait = 1;
    $from = '';
    $port = 0;
    socket_recvfrom($sock, $buf, 1024, 0, $from, $port);
    echo "Received $buf from remote address $from and remote port $port and got: " .$buf. PHP_EOL;

    $data = explode("|",trim($buf));
    switch($data[0]){
        case 1:
            $users[count($users)] = array('ip' => $from, 'port'=>$port, 'name'=>$data[1]);
            break;
        case 2:
            for($i=0;$i<count($users);$i++){
                if($users[$i]['name']==$data[1]){
                    $buf = $users[$i]['ip']."|".$users[$i]['port'];
                    echo "Sending ".$buf.PHP_EOL;
                    socket_sendto($sock, $buf, strlen($buf), 0, $from, $port);
                    break;
                }
            }

            break;
    }

}

// close the listening socket
socket_close($sock);