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PHP5中文手册

stream_socket_recvfrom

(PHP 5)

stream_socket_recvfrom — Receives data from a socket, connected or not

Description

string stream_socket_recvfrom ( resource $socket , int $length [, int $flags [, string &$address ]] )

The function stream_socket_recvfrom() accepts data from a remote socket up to length bytes. If address is provided it will be populated with the address of the remote socket.

The value of flags can be any combination of the following:

possible values for flags
STREAM_OOB Process OOB (out-of-band) data.
STREAM_PEEK Retrieve data from the socket, but do not consume the buffer. Subsequent calls to fread() or stream_socket_recvfrom() will see the same data.

Example#1 stream_socket_recvfrom() Example

<?php
/* Open a server socket to port 1234 on localhost */
$server stream_socket_server('tcp://127.0.0.1:1234');

/* Accept a connection */
$socket stream_socket_accept($server);

/* Grab a packet (1500 is a typical MTU size) of OOB data */
echo "Received Out-Of-Band: '" stream_socket_recvfrom($socket1500STREAM_OOB) . "'\n";

/* Take a peek at the normal in-band data, but don't comsume it. */
echo "Data: '" stream_socket_recvfrom($socket1500STREAM_PEEK) . "'\n";

/* Get the exact same packet again, but remove it from the buffer this time. */
echo "Data: '" stream_socket_recvfrom($socket1500) . "'\n";

/* Close it up */
fclose($socket);
fclose($server);
?>

Note: If a message received is longer than the length parameter, excess bytes may be discarded depending on the type of socket the message is received from (such as UDP).

Note: Calls to stream_socket_recvfrom() on socket-based streams, after calls to buffer-based stream functions (like fread() or stream_get_line()) read data directly from the socket and bypass the stream buffer.

See also stream_socket_sendto(), stream_socket_client(), and stream_socket_server().