Beware, when using this function within a loop (i.e. a demon with a socket). The socket_accept(), for example, emits a warning each time there is no incoming connection available to be read. My php error log file got huge in a matter of seconds, eventually crashing the server.
Of course, i used the @ before the function to take care of that problem.
[EDITOR: One can (and should) use socket_select to detect a new connection on a socket (it's a "readable" event)]