(PHP 4 >= 4.1.0, PHP 5)
socket_listen — Listens for a connection on a socket
$socket
   [, int $backlog = 0
  ] )
   After the socket socket has been created
   using socket_create() and bound to a name with
   socket_bind(), it may be told to listen for incoming
   connections on socket.
  
   socket_listen() is applicable only to sockets of
   type SOCK_STREAM or
   SOCK_SEQPACKET.
  
socketA valid socket resource created with socket_create().
backlog
       A maximum of backlog incoming connections will be
       queued for processing. If a connection request arrives with the queue
       full the client may receive an error with an indication of
       ECONNREFUSED, or, if the underlying protocol supports
       retransmission, the request may be ignored so that retries may succeed.
      
Note:
The maximum number passed to the
backlogparameter highly depends on the underlying platform. On Linux, it is silently truncated toSOMAXCONN. On win32, if passedSOMAXCONN, the underlying service provider responsible for the socket will set the backlog to a maximum reasonable value. There is no standard provision to find out the actual backlog value on this platform.
   Returns TRUE on success or FALSE on failure. The error code can be retrieved with
   socket_last_error(). This code may be passed to
   socket_strerror() to get a textual explanation of the
   error.