LXXVI. Socket functions
The socket extension implements a low-level interface to the
socket communication functions, providing the possibility to act
as a socket server as well as a client.
For a more generic client-side socket interface, see
fsockopen() and
pfsockopen().
When using the socket functions described here, it is important to
remember that while many of them have identical names to their C
counterparts, they often have different declarations. Please be
sure to read the descriptions to avoid confusion.
That said, those unfamiliar with socket programming can still find
a lot of useful material in the appropriate Unix man pages, and
there is a great deal of tutorial information on socket
programming in C on the web, much of which can be applied, with
slight modifications, to socket programming in PHP.
Ejemplo 1. Socket example: Simple TCP/IP server
This example shows a simple talkback server. Change the
address and port variables
to suit your setup and execute. You may then connect to the
server with a command similar to: telnet 192.168.1.53
10000 (where the address and port match your
setup). Anything you type will then be output on the server
side, and echoed back to you. To disconnect, enter 'quit'.
<?php
error_reporting(E_ALL);
/* Allow the script to hang around waiting for connections. */
set_time_limit(0);
$address = '192.168.1.53';
$port = 10000;
if (($sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
echo "socket() failed: reason: " . strerror($sock) . "\n";
}
if (($ret = bind($sock, $address, $port)) < 0) {
echo "bind() failed: reason: " . strerror($ret) . "\n";
}
if (($ret = listen($sock, 5)) < 0) {
echo "listen() failed: reason: " . strerror($ret) . "\n";
}
do {
if (($msgsock = accept_connect($sock)) < 0) {
echo "accept_connect() failed: reason: " . strerror($msgsock) . "\n";
break;
}
do {
$buf = '';
$ret = read($msgsock, $buf, 2048);
if ($ret < 0) {
echo "read() failed: reason: " . strerror($ret) . "\n";
break 2;
}
if ($ret == 0) {
break 2;
}
$buf = trim($buf);
if ($buf == 'quit') {
close($msgsock);
break 2;
}
$talkback = "PHP: You said '$buf'.\n";
write($msgsock, $talkback, strlen($talkback));
echo "$buf\n";
} while (true);
close($msgsock);
} while (true);
close($sock);
?>
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Ejemplo 2. Socket example: Simple TCP/IP client
This example shows a simple, one-shot HTTP client. It simply
connects to a page, submits a HEAD request, echoes the reply,
and exits.
<?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.php.net');
/* Create a TCP/IP socket. */
$socket = socket(AF_INET, SOCK_STREAM, 0);
if ($socket < 0) {
echo "socket() failed: reason: " . strerror($socket) . "\n";
} else {
"socket() successful: " . strerror($socket) . "\n";
}
echo "Attempting to connect to '$address' on port '$service_port'...";
$result = connect($socket, $address, $service_port);
if ($result < 0) {
echo "connect() failed.\nReason: ($result) " . strerror($result) . "\n";
} else {
echo "OK.\n";
}
$in = "HEAD / HTTP/1.0\r\n\r\n";
$out = '';
echo "Sending HTTP HEAD request...";
write($socket, $in, strlen($in));
echo "OK.\n";
echo "Reading response:\n\n";
while (read($socket, $out, 2048)) {
echo $out;
}
echo "Closing socket...";
close($socket);
echo "OK.\n\n";
?>
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- Tabla de contenidos
- accept_connect — Accepts a connection on a socket.
- bind — Binds a name to a socket.
- connect — Initiates a connection on a socket.
- listen — Listens for a connection on a socket.
- socket — Create a socket (endpoint for communication).
- strerror — Return a string describing a socket error.