(PHP 4 >= 4.1.0, PHP 5, PHP 7)
socket_listen — Listens for a connection on a socket
$socket
[, int $backlog
= 0
] ) : bool
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
.
socket
A valid socket resource 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 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.
成功时返回 TRUE
, 或者在失败时返回 FALSE
。 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.