在PHP中为聊天创建客户端

<?PHP

function chat_leave( $sock,$chat_id = 0 )
{
    if( $chat_room_id[ $chat_id ] )
    {
        unset( $chat_room_id[ $chat_id ] ); 
        return true;
    }
    socket_close($sock);
    return false;
}

function client( $input )
{
    /*
    Simple PHP udp socket client
    */

    //Reduce errors
    error_reporting(~E_WARNING);

    $server = '127.0.0.1';
    $port = 9999;

    if(!($sock = socket_create(AF_INET,SOCK_DGRAM,0)))
    {
        $errorcode = socket_last_error();
        $errormsg = socket_strerror($errorcode);

        die("Couldn't create socket: [$errorcode] $errormsg \n");
    }

    //Communication loop
    while(1)
    {

        //Send the message to the server
        if( ! socket_sendto($sock,$input,strlen($input),$server,$port))
        {
            $errorcode = socket_last_error();
            $errormsg = socket_strerror($errorcode);

            die("Could not send data: [$errorcode] $errormsg \n");
        }

        //Now receive reply from server and print it
        if(socket_recv ( $sock,$reply,2045,MSG_WAITALL ) === FALSE)
        {
            $errorcode = socket_last_error();
            $errormsg = socket_strerror($errorcode);

            die("Could not receive data: [$errorcode] $errormsg \n");
        }

        return $reply;
    }
}
/*
 * chat_join
 * a new user joins the chat
 * @username: String
 * @password: String
 * 
 * add a new listener to the server
 * 
 */
function chat_join( $username = "",$password = "" )
{
    $users = array(
        "batman" => "batman123","robin"  => "robin123","joe"    => "joe123"
    );
    if( $users[$username] == $password )
    {
        return true;
    }

    return false;   
}
function main()
{
    $chat_room_id = array();

    $username = stripslashes( $_POST['username'] );
    $password = stripslashes( $_POST['password'] );
    $action   = stripslashes( $_POST['action'] );
    $port     = intval( $_POST['port'] );
    $domain   = stripslashes( $_POST['domain'] );
    $chat_id  = intval( $_POST['chat_room_id'] );

    if( strcmp( $action,"login" ) == 0 )
    {
        $status = chat_join( $username,$password );
        if( $status )
        {
            $chat_room_id[] = $chat_id;
            echo json_encode( $status );
        }
    }
    else if( strcmp( $action,"chat" ) == 0 )
    {
        $msg = stripslashes( $_POST['message'] );
        // take the message,send through the client
        $reply = client( $msg );
        echo json_encode( $reply );
    }
    else if( strcmp( $action,"logout") == 0 )
    {

    }
    else
    {
        echo json_encode( false );
    }
    return;
}

main();

?>

函数client()是我从client.PHP文件获得的代码,当我在终端上执行时,它能够从server.PHP发送和接收消息.现在我想使用我的main.PHP文件,因此一旦用户登录,他将向服务器发送消息,服务器将回复用户未看到的消息.
当我从两个不同的终端运行server.PHP和client.PHP时,我能够发送和接收消息,但是我想使用main.PHP这样做,将该回复消息转换为JSON对象并发送回html页面,它将被附加到textarea框.
我的问题是：如何获得client.PHP收到的回复并将其发送回html页面？
当我在终端上执行它时,我有：

Enter a message to send : hello
Reply : hello

我使用AJAX在聊天中发送用户输入,所以我希望能够接收该消息,并将其发送到服务器,我在终端上启动并回复并转发到网页并将其附加到文本框区域.
我怎么能做到这一点？我应该通过main.PHP启动client.PHP作为服务吗？或者我应该使用客户端($input)函数发送消息,然后返回它发送的内容,返回？
但是,我希望该客户端在用户注销之前一直运行,因为其他客户端可能会连接到聊天.我怎么能做到这一点对我来说有点模糊.客户端($input)中的代码与client.PHP中的代码相同.