PHP監聽Socket

<?php
set_time_limit(10);
$commonProtocol = getprotobyname("tcp");
$socket = socket_create(AF_INET, SOCK_STREAM, $commonProtocol);
if ($socket) {
$result = socket_bind($socket, 'localhost', 1337);
if ($result) {
   $result = socket_listen($socket, 5);
   if ($result) {
    echo "監聽成功";
   }
}
}else{
echo "監聽失敗";
}
do {
if (($msgsock = socket_accept($socket))) { /* 發送提示信息給連接上來的用戶 */
   $msg = "==========================================\r\n" .
   "Welcome to the PHP Test Server. \r\n\r\n" .
   "To quit, type 'quit'. \r\n" .
   "To shut down the server type 'shutdown'.\r\n" .
   "To get help message type 'help'.\r\n" .
   "==========================================\r\n" .
   "php>";
}
socket_write($msgsock, $msg, strlen($msg));
do {
   $buf = socket_read($msgsock, 2048, PHP_BINARY_READ);
   if (false === $buf) {
    echo "socket_read() failed: reason: " . socket_strerror($result) . "\n";
    break 2;
   }
   if (!$buf = trim($buf)) {
    continue;
   } /* 客戶端輸入quit命令時候關閉客戶端連接 */
   if ($buf == 'q') {
    break;
   } /* 客戶端輸入shutdown命令時候服務端和客戶端都關閉 */
   if ($buf == 'shutdown') {
    socket_close($msgsock);
    break 2;
   } /* 客戶端輸入help命令時候輸出幫助信息 */
   if ($buf == 'h') {
    $msg = " PHP Server Help Message \r\n\r\n" .
    " To quit, type 'quit'. \r\n" .
    " To shut down the server type 'shutdown'.\r\n" .
    " To get help message type 'help'.\r\n" .
    "php> ";
    socket_write($msgsock, $msg, strlen($msg));
    continue;
   } /* 客戶端輸入命令不存在時提示信息 */
   $talkback = "PHP: unknow command '$buf'.\r\nphp> ";
   socket_write($msgsock, $talkback, strlen($talkback));
   echo "$buf\n";
} while (true);
socket_close($msgsock);
}while (true);
/* 關閉Socket連接 */
socket_close($socket);
?>