It seems that most HTML5 web socket example online with PHP are using the socket plugin. Is it possible to use stream_socket_server with HTML5 web socket?
If yes, I am trying to build a simple socket server + client with PHP stream_socket_server function. Here is the code:
PHP socket server:
<?php
$server = stream_socket_server("tcp://localhost:8080", $errno, $errorMessage);
if ($server === false) {
throw new UnexpectedValueException("Could not bind to socket: $errorMessage");
}
for (;;) {
$client = stream_socket_accept($server);
if ($client) {
echo 'Connection accepted from '.stream_socket_get_name($client, false) . "\n";
stream_copy_to_stream($client, $client);
}
}
HTML5 Web Socket Client.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Client Testing</title>
<script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>
</head>
<body>
<button id="send">Testing button</button>
<script>
websocket = new WebSocket("ws://localhost:8080");
websocket.onopen = function(evt) { /* do stuff */ }; //on open event
websocket.onclose = function(evt) { /* do stuff */ }; //on close event
websocket.onmessage = function(evt) { /* do stuff */ }; //on message event
websocket.onerror = function(evt) { /* do stuff */ }; //on error event
$('#send').click( function(){
websocket.send("This is a testing message"); //send method
});
//websocket.close(); //close method
</script>
</body>
</html>
And this is the return when I am connecting:
WebSocket connection to 'ws://localhost:8080/' failed: Error during WebSocket handshake: net::ERR_INVALID_HTTP_RESPONSE
What have I missed? How do I return a valid HTTP response?
You get this error ERR_INVALID_HTTP_RESPONSE because you don't send the appripriate response through your socket.
A response from the server to the client looks like this:
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
Sec-WebSocket-Protocol: chat
So you need to write that to the socket:
socket_write($accept, $httpResponse);
You also need to implement polling via socket_select(), currently your program is not able to handle more than a single connection.
Also don't forget to use socket_close() when you're done.
Old Answer
A generic socket is opened upon OSI layer 4. You open a UNIX socket, a TCP socket, a UDP socket.
It is also possible to open sockets on lower OSI layers like for ICMP or even IP which are generally called "raw sockets".
A Websocket is an Application layer protocol - OSI layer 7. A Websocket uses a generic socket (single duplex TCP connection) to send and receive its data.
You cannot connect one to the other without further implementation. A Websocket is build upon a normal socket.
See: