socket_recv
(PHP 4 >= 4.1.0, PHP 5, PHP 7)
socket_recv — Receives data from a connected socket
Description
int socket_recv ( resource $socket , string &$buf , int $len , int $flags ) 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 to NULL.
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.
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.← socket_read
socket_recvfrom →
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