socket_recv
(PHP 4 >= 4.1.0, PHP 5, PHP 7)
socket_recv — Receives data from a connected socket
Description
$socket
, string &$buf
, int $len
, int $flags
) : int
The socket_recv() function receives
len
bytes of data in buf
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.
buf
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 buf
.
Parameters
-
socket
-
The
socket
must be a socket resource previously created by socket_create(). -
buf
-
The data received will be fetched to the variable specified with
buf
. If an error occurs, if the connection is reset, or if no data is available,buf
will be set toNULL
. -
len
-
Up to
len
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.Possible values for flags
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 len
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.
Return Values
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.
Examples
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.
English translation
You have asked to visit this site in English. For now, only the interface is translated, but not all the content yet.If you want to help me in translations, your contribution is welcome. All you need to do is register on the site, and send me a message asking me to add you to the group of translators, which will give you the opportunity to translate the pages you want. A link at the bottom of each translated page indicates that you are the translator, and has a link to your profile.
Thank you in advance.
Document created the 30/01/2003, last modified the 26/10/2018
Source of the printed document:https://www.gaudry.be/en/php-rf-function.socket-recv.html
The infobrol is a personal site whose content is my sole responsibility. The text is available under CreativeCommons license (BY-NC-SA). More info on the terms of use and the author.
References
These references and links indicate documents consulted during the writing of this page, or which may provide additional information, but the authors of these sources can not be held responsible for the content of this page.
The author This site is solely responsible for the way in which the various concepts, and the freedoms that are taken with the reference works, are presented here. Remember that you must cross multiple source information to reduce the risk of errors.