PHP unread_bytes在PHP 5.3中工作，但在PHP 5.4中不工作

Question

I have a problem with a connection to a telnet-server using PHP sockets. I've a finished telnet class, but on my other server did that class not work because of the stream_get_meta_data unread_bytes value. Does PHP have changed that in Version 5.4? I can't find what about this change.

The code that i use:

        $buff = '';
        while (!feof($this->socket)) {
            $buff .= fread($this->socket, 1024);
            $stream_meta_data = stream_get_meta_data($this->socket);
            if ($stream_meta_data['unread_bytes'] <= 0)
                break;
        }

Can anyone help me or say me, what can i change?

Answer 1

You didn't clearly state what your code snippet is supposed to do:

1. read bytes until the socket connection is shut down, or
2. read bytes that are available at the moment, on a live connection.

But your comment feof() dont work correctly suggests that you're after 2., since a feof() check would be sufficient for 1.; cf. the comment from Wez to the "Not a bug" unread_bytes always 0:

unread_bytes is the number of bytes remaining in PHPs buffering layer after the last read.
If you have consumed all data from the buffer on a prior read, unread_bytes will remain at zero until you next read a chunk of data from the network.
So, unread_bytes should not be used to determine if more data is pending; you should use either:

feof() to detect end of file. Don't forget that you can use non-blocking mode here. PHP 4.3 has a new function called stream_select() which behaves like socket_select() from the sockets extension, but works on all files returned by fopen() and fsockopen(). You can use it to test which files are ready for reading/writing and also specify a timeout.

So, if you want 2., you can use stream_select() or socket_select().