(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
socket_recvfrom — Receives data from a socket whether or not it is connection-oriented
$socket
,&$data
,$length
,$flags
,&$address
,&$port
= null
The socket_recvfrom() function receives
length
bytes of data in data
from
address
on port port
(if the
socket is not of type AF_UNIX
) using
socket
. socket_recvfrom() can be
used to gather data from both connected and unconnected sockets.
Additionally, one or more flags can be specified to modify the behaviour of
the function.
The address
and port
must be
passed by reference. If the socket is not connection-oriented,
address
will be set to the internet protocol address of
the remote host or the path to the UNIX socket. If the socket is
connection-oriented, address
is null
. Additionally,
the port
will contain the port of the remote host in
the case of an unconnected AF_INET
or
AF_INET6
socket.
注意: 此函数可安全用于二进制对象。
socket
The socket
must be a Socket instance previously
created by socket_create().
data
The data received will be fetched to the variable specified with
data
.
length
Up to length
bytes will be fetched from remote host.
flags
The value of flags
can be any combination of
the following flags, joined with the binary OR (|
)
operator.
Flag | Description |
---|---|
MSG_OOB |
Process out-of-band data. |
MSG_PEEK |
Receive data from the beginning of the receive queue without removing it from the queue. |
MSG_WAITALL |
Block until at least length are received.
However, if a signal is caught or the remote host disconnects, the
function may return less data.
|
MSG_DONTWAIT |
With this flag set, the function returns even if it would normally have blocked. |
address
If the socket is of the type AF_UNIX
type,
address
is the path to the file. Else, for
unconnected sockets, address
is the IP address of,
the remote host, or null
if the socket is connection-oriented.
port
This argument only applies to AF_INET
and
AF_INET6
sockets, and specifies the remote port
from which the data is received. If the socket is connection-oriented,
port
will be null
.
socket_recvfrom() returns the number of bytes received,
or false
if there was an error. The actual error code can be retrieved by
calling socket_last_error(). This error code may be
passed to socket_strerror() to get a textual explanation
of the error.
版本 | 说明 |
---|---|
8.0.0 |
现在 socket 是 Socket 实例,
之前是 resource。
|
示例 #1 socket_recvfrom() example
<?php
$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
socket_bind($socket, '127.0.0.1', 1223);
$from = '';
$port = 0;
socket_recvfrom($socket, $buf, 12, 0, $from, $port);
echo "Received $buf from remote address $from and remote port $port" . PHP_EOL;
?>
This example will initiate a UDP socket on port 1223 of 127.0.0.1 and print at most 12 characters received from a remote host.