Can't read from socket (hangs)

Question

I am using PHP to connect to a local C++ socket server to keep state between a web app and a couple of daemons. I can send data to the socket server, but not receive from it; i

Answer 1

Sockets in PHP, as in most programming languages, are opened in blocking mode by default, unless set otherwise using socket_set_nonblock.

This means that unless a timeout/error occurs or data is received, socket_read will hang there forever.

Since your termination character seems to be a new line, try that:

while($resp = socket_read($sock, 1000)) {
   $str .= $resp;
   if (strpos($str, "\n") !== false) break;
}
socket_close($sock);
die("Server said: $str");