php man page for socket_listen

SOCKET_LISTEN(3)							 1							  SOCKET_LISTEN(3)

socket_listen - Listens for a connection on a socket

SYNOPSIS
       bool socket_listen (resource  $socket, [int  $backlog])

DESCRIPTION
	After  the  socket  $socket  has been created using socket_create(3) and bound to a name with socket_bind(3), it may be told to listen for
       incoming connections on $socket.

       socket_listen(3) is applicable only to sockets of type SOCK_STREAM or SOCK_SEQPACKET.

PARAMETERS
	      o $socket
		- A valid socket resource created with socket_create(3).

	      o $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 $backlog parameter highly depends on the underlying platform.  On  Linux,  it  is  silently
		     truncated	to  SOMAXCONN.	On win32, if passed SOMAXCONN, 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  plat-
		     form.

RETURN VALUES
	Returns  TRUE  on  success  or	FALSE  on  failure.  The error code can be retrieved with socket_last_error(3). This code may be passed to
       socket_strerror(3) to get a textual explanation of the error.

SEE ALSO
       socket_accept(3), socket_bind(3), socket_connect(3), socket_create(3), socket_strerror(3).

PHP Documentation Group 													  SOCKET_LISTEN(3)