PHP. Руководство по PHP. 2005

Socket Functions

CXXVIII. Socket Functions

Введение

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.

Требования

Эти функции всегда доступны.

Установка

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.

Замечание:Поддержка IPv6 была добавлена в PHP5.0.0.

Настройка во время выполнения

Данное расширение не определяет никакие директивы конфигурации в php.ini.

Типы ресурсов

Данное расширение не определяет никакие типы ресурсов.

Предопределенные константы

-Перечисленные ниже константы определены данным расширением и могут быть

доступны только в том случае, если PHP был собран с

поддержкой этого расширения или же в том случае, если

данное расширение подгружается во время выполнения.

AF_UNIX (integer)

AF_INET (integer)

AF_INET6 (integer)

SOCK_STREAM (integer)

SOCK_DGRAM (integer)

SOCK_RAW (integer)

SOCK_SEQPACKET (integer)

SOCK_RDM (integer)

MSG_OOB (integer)

MSG_WAITALL (integer)

MSG_PEEK (integer)

MSG_DONTROUTE (integer)

SO_DEBUG (integer)

SO_REUSEADDR (integer)

SO_KEEPALIVE (integer)

SO_DONTROUTE (integer)

SO_LINGER (integer)

SO_BROADCAST (integer)

SO_OOBINLINE (integer)

SO_SNDBUF (integer)

SO_RCVBUF (integer)

SO_SNDLOWAT (integer)

SO_RCVLOWAT (integer)

SO_SNDTIMEO (integer)

SO_RCVTIMEO (integer)

SO_TYPE (integer)

SO_ERROR (integer)

SOL_SOCKET (integer)

PHP_NORMAL_READ (integer)

PHP_BINARY_READ (integer)

SOL_TCP (integer)

SOL_UDP (integer)

Socket Errors

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.

Замечание: 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):

Warning - socket_bind() unable to bind address [98]: Die Adresse wird bereits verwendet

Примеры

Пример 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
<?
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);

?>

Пример 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.


<?
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";

?>

Содержание

socket_accept -- Accepts a connection on a socket

socket_bind -- Binds a name to a socket

socket_clear_error -- Clears the error on the socket or the last error code

socket_close -- Closes a socket resource

socket_connect -- Initiates a connection on a socket

socket_create_listen -- Opens a socket on port to accept connections

socket_create_pair -- Creates a pair of indistinguishable sockets and stores them in an array

socket_create -- Create a socket (endpoint for communication)

socket_get_option -- Gets socket options for the socket

socket_getpeername -- Queries the remote side of the given socket which may either result in host/port or in a Unix filesystem path, dependent on its type

socket_getsockname -- Queries the local side of the given socket which may either result in host/port or in a Unix filesystem path, dependent on its type

socket_last_error -- Returns the last error on the socket

socket_listen -- Listens for a connection on a socket

socket_read -- Reads a maximum of length bytes from a socket

socket_recv -- Receives data from a connected socket

socket_recvfrom -- Receives data from a socket, connected or not

socket_select -- Runs the select() system call on the given arrays of sockets with a specified timeout

socket_send -- Sends data to a connected socket

socket_sendto -- Sends a message to a socket, whether it is connected or not

socket_set_block -- Sets blocking mode on a socket resource

socket_set_nonblock -- Sets nonblocking mode for file descriptor fd

socket_set_option -- Sets socket options for the socket

socket_shutdown -- Shuts down a socket for receiving, sending, or both