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CX. Socket Functions
The socket extension implements a low-level interface to the socket
communication functions based on the popular BSD sockets, providing the
possibility to act as a socket server as well as a client.
For a more generic client-side socket interface, see
stream_socket_client(),
stream_socket_server(),
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.
Those unfamiliar with socket programming can 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. The Unix Socket
FAQ might be a good start.
| 警告 | 本扩展模块是实验性的。该模块的行为，包括其函数的名称以及其它任何关于此模块的文档可能会在没有通知的情况下随 PHP 以后的发布而改变。我们提醒您在使用本扩展模块的同时自担风险。
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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.
注: IPv6 支持是 PHP 5.0.0 新加的。
由于这些常量是由该扩展模块定义的，因此只有在该扩展模块被编译到 PHP 中，或者在运行时被动态加载后，这些常量才有效。
The socket extension was written to provide a usable interface to the
powerful BSD sockets. Care has been taken that the functions work equally
well on Win32 and Unix implementations. Almost all of the sockets
functions may fail under certain conditions and therefore emit an
E_WARNING message describing the error. Sometimes this
doesn't happen to the desire of the developer. For example the function
socket_read() may suddenly emit an
E_WARNING message because the connection broke
unexpectedly. It's common to suppress the warning with the
@-operator and catch the error code within the
application with the socket_last_error() function. You
may call the socket_strerror() function with this error
code to retrieve a string describing the error. See their description for
more information.
注:
The E_WARNING messages generated by the socket
extension are in English though the retrieved error message will appear
depending on the current locale (LC_MESSAGES):
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Warning - socket_bind() unable to bind address [98]: Die Adresse wird bereits verwendet
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例子 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'.
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#!/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, SOL_TCP)) < 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, PHP_NORMAL_READ))) {
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);
?>
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例子 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.
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<?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 < 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/1.1\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";
while ($out = socket_read($socket, 2048)) {
echo $out;
}
echo "Closing socket...";
socket_close($socket);
echo "OK.\n\n";
?>
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 add a note
User Contributed Notes
Socket Functions
judeman at yahoo dot com
05-Jun-2001 01:49
After several hours of working with sockets in an attempt to do UDP
broadcasting, I thought a little help was in order for anyone else looking
to do something similar, since it uses a number of those
"undocumented" functions. Here's how I did
it:
<?php
// here is a basic opening of the a socket.
AF_INET specifies the internet domain. SOCK_DGRAM
// specifies the
Datagram socket type the 0 specifies that I want to use the default protcol
(which in this
// case is UDP)
$sock = socket(AF_INET, SOCK_DGRAM,
0);
// if the file handle assigned to socket is less than 0 then
opening the socket failed
if($sock < 0)
{
echo
"socket() failed, error: " . strerror($sock) .
"\n";
}
// here's where I set the socket options,
this is essential to allow broadcasting. An earlier comment (as of
//
June 4th, 2001) explains what the parameters are. For my purposes (UDP
broadcasting) I need to set
// the broadcast option at the socket
level to true. In C, this done using SOL_SOCKET as the level param
//
(2) and SO_BROADCAST as the type param (3). These may exist in PHP but I
couldn't reference them
// so I used the values that referencing
these variables in C returns (namely 1 and 6 respectively). This
//
function is basically just a wrapper to the C function so check out the C
documentation for more info
$opt_ret = setsockopt($sock, 1, 6,
TRUE);
// if the return value is less than one, an error occured
setting the options
if($opt_ret < 0)
{
echo
"setsockopt() failed, error: " . strerror($opt_ret) .
"\n";
}
// finally I am ready to broad cast
something. The sendto function allows this without any
// connections
(essential for broadcasting). So, this function sends the contents of
$broadcast_string to the
// general broadcast address (255.255.255.255)
on port 4096. The 0 (param 4) specifies no special
// options, you can
read about the options with man sendto
$send_ret = sendto($sock,
$broadcast_string, strlen($broadcast_string), 0, '255.255.255.255',
4096);
// if the return value is less than 0, an error has occured
if($send_ret < 0)
{
echo "sendto() failed, error:
" . strerror($send_ret) . "
\n"; }
//
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snmpwalkoid
