| Warning |
This extension is
EXPERIMENTAL. The behaviour of this extension,
including the names of its functions, and anything else documented
about this extension may change in a future release of PHP without
notice. Be warned and use this extension at your own
risk. |
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.
The socket functions described here are part of an extension to
PHP which must be enabled at compile time by giving the --enable-sockets option to
configure.
For a more generic client-side socket interface, see
fsockopen() and
pfsockopen().
When using these functions, 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.
Example 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'.
#!/usr/local/bin/php -q
<?php
error_reporting (E_ALL);
/* Allow the script to hang around waiting for connections. */
set_time_limit (0);
/* Turn on implicit output flushing so we see what we're getting
* as it comes in. */
ob_implicit_flush ();
$address = '192.168.1.53';
$port = 10000;
if (($sock = socket_create (AF_INET, SOCK_STREAM, 0)) < 0) {
echo "socket_create() failed: reason: " . socket_strerror ($sock) . "\n";
}
if (($ret = socket_bind ($sock, $address, $port)) < 0) {
echo "socket_bind() failed: reason: " . socket_strerror ($ret) . "\n";
}
if (($ret = socket_listen ($sock, 5)) < 0) {
echo "socket_listen() failed: reason: " . socket_strerror ($ret) . "\n";
}
do {
if (($msgsock = socket_accept($sock)) < 0) {
echo "socket_accept() failed: reason: " . socket_strerror ($msgsock) . "\n";
break;
}
/* Send instructions. */
$msg = "\nWelcome to the PHP Test Server. \n" .
"To quit, type 'quit'. To shut down the server type 'shutdown'.\n";
socket_write($msgsock, $msg, strlen($msg));
do {
if (FALSE === ($buf = socket_read ($msgsock, 2048))) {
echo "socket_read() failed: reason: " . socket_strerror ($ret) . "\n";
break 2;
}
if (!$buf = trim ($buf)) {
continue;
}
if ($buf == 'quit') {
break;
}
if ($buf == 'shutdown') {
socket_close ($msgsock);
break 2;
}
$talkback = "PHP: You said '$buf'.\n";
socket_write ($msgsock, $talkback, strlen ($talkback));
echo "$buf\n";
} while (true);
socket_close ($msgsock);
} while (true);
socket_close ($sock);
?> |
|
Example 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. */
$socket = socket_create (AF_INET, SOCK_STREAM, 0);
if ($socket < 0) {
echo "socket_create() failed: reason: " . socket_strerror ($socket) . "\n";
} else {
echo "OK.\n";
}
echo "Attempting to connect to '$address' on port '$service_port'...";
$result = socket_connect ($socket, $address, $service_port);
if ($result < 0) {
echo "socket_connect() failed.\nReason: ($result) " . socket_strerror($result) . "\n";
} else {
echo "OK.\n";
}
$in = "HEAD / HTTP/1.0\r\n\r\n";
$out = '';
echo "Sending HTTP HEAD request...";
socket_write ($socket, $in, strlen ($in));
echo "OK.\n";
echo "Reading response:\n\n";
while ($out = socket_read ($socket, 2048)) {
echo $out;
}
echo "Closing socket...";
socket_close ($socket);
echo "OK.\n\n";
?> |
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