Websocket client for PHP

UPDATE 2019: Some servers require a longer key, than I previously used, resulting in connection refused. this has now been changed.

Use PHP to connect to at websocket service. Thise 3 functions makes the websocket negotiation and connection and handle the hybi10 frame encoding required.

Example 1:

if( $sp = websocket_open('echo.websocket.org',80) ) {
   websocket_write($sp,"hello server");
   echo "Server responed with: " . websocket_read($sp,$errstr);
}

Example 2, using a session cookie and setting timeout:

$headers = ["Cookie: SID=".session_id()];
$sp = websocket_open('echo.websocket.org',80,$headers,$errstr,16);
if($sp){
   $bytes_written = websocket_write($sp,"hello server");
   if($bytes_written){
     $data = websocket_read($sp,$errstr);
     echo "Server responed with: " . $errstr ? $errstr : $data;
   }
}

Functions:

websocket_open

Open websocket connection

resource websocket_open(string $host [,int $port [,array $additional_headers [,string &error_string ,[, int $timeout]]]] )

host A host URL. It can be a domain name like www.example.com or an IP address like local host: 127.0.0.1

port The servers port number

headers (optional) additional HTTP headers to attach to the request. For example to parse a session cookie.

error_string (optional) A referenced variable to store error messages, if any.

timeout (optional) The maximum time in seconds, a read operation will wait for an answer from the server. Default value is 10 seconds.

returns a resource handle or false.

websocket_write

Send data to server through the websocket, using hybi10 frame encoding.

int websocket_write(resource $handle, string $data [,boolean $final])

handle the resource handle returned by websocket_open, if successful

data Data to transport to server

final (optional) indicate if this block is the final data block of this request. Default true

websocket_read

Read data through websocket from the server, using hybi10 frame encoding.

string websocket_read(resource $handle [,string &error_string])

handle the resource handle returned by websocket_open, if successful.

error_string (optional) A referenced variable to store error messages, i any.

Note:

This implementation waits for the final chunk of data, before returning.
Reading data while handling/ignoring other kind of packages

Contribute

Please let me know if there is any problems with the code. Any contributions are accepted, if the code looks nice, not bloated and otherwise reasonable.