(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
socket_recv — Receives data from a connected socket
The socket_recv() function receives
length bytes of data in data from
socket. socket_recv() can
be used to gather data from connected sockets. Additionally, one or
more flags can be specified to modify the behaviour of the
function.
data is passed by reference, so it must be
specified as a variable in the argument list. Data read from
socket by socket_recv()
will be returned in data.
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. If an error occurs, if the
connection is reset, or if no data is
available, data will be set to null.
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. |
socket_recv() 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.
Example #1 socket_recv() example
This example is a simple rewrite of the first example from Examples to use socket_recv().
<?php
error_reporting(E_ALL);
echo "<h2>TCP/IP Connection</h2>\n";
/* Get the port for the WWW service. */
$service_port = getservbyname('www', 'tcp');
/* Get the IP address for the target host. */
$address = gethostbyname('www.example.com');
/* Create a TCP/IP socket. */
$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if ($socket === false) {
echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
} else {
echo "OK.\n";
}
echo "Attempting to connect to '$address' on port '$service_port'...";
$result = socket_connect($socket, $address, $service_port);
if ($result === false) {
echo "socket_connect() failed.\nReason: ($result) " . socket_strerror(socket_last_error($socket)) . "\n";
} else {
echo "OK.\n";
}
$in = "HEAD / HTTP/1.1\r\n";
$in .= "Host: www.example.com\r\n";
$in .= "Connection: Close\r\n\r\n";
$out = '';
echo "Sending HTTP HEAD request...";
socket_write($socket, $in, strlen($in));
echo "OK.\n";
echo "Reading response:\n\n";
$buf = 'This is my buffer.';
if (false !== ($bytes = socket_recv($socket, $buf, 2048, MSG_WAITALL))) {
echo "Read $bytes bytes from socket_recv(). Closing socket...";
} else {
echo "socket_recv() failed; reason: " . socket_strerror(socket_last_error($socket)) . "\n";
}
socket_close($socket);
echo $buf . "\n";
echo "OK.\n\n";
?>The above example will produce something like:
<h2>TCP/IP Connection</h2> OK. Attempting to connect to '208.77.188.166' on port '80'...OK. Sending HTTP HEAD request...OK. Reading response: Read 123 bytes from socket_recv(). Closing socket...HTTP/1.1 200 OK Date: Mon, 14 Sep 2009 08:56:36 GMT Server: Apache/2.2.3 (Red Hat) Last-Modified: Tue, 15 Nov 2005 13:24:10 GMT ETag: "b80f4-1b6-80bfd280" Accept-Ranges: bytes Content-Length: 438 Connection: close Content-Type: text/html; charset=UTF-8 OK.