Socket Functions
PHP Manual

socket_listen

Listens for a connection on a socket

Description

bool socket_listen(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.

Parameters

socket

A Socket instance created with socket_create or socket_addrinfo_bind

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 platform.

Return Values

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.

Changelog

Version Description
8.0.0 socket is a Socket instance now; previously, it was a resource.

See Also

  • socket_accept
  • socket_bind
  • socket_connect
  • socket_create
  • socket_strerror
  • socket_addrinfo_bind