XCIV. Socket functions
| 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'.
<?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_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;
}
do {
$buf = '';
$ret = socket_read ($msgsock, $buf, 2048);
if ($ret < 0) {
echo "socket_read() failed: reason: " . socket_strerror ($ret) . "\n";
break 2;
}
if ($ret == 0) {
break 2;
}
$buf = trim ($buf);
if ($buf == 'quit') {
socket_close ($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 ($socket) . "\n";
} else {
"socket_create() successful: " . socket_strerror ($socket) . "\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 (socket_read ($socket, $out, 2048)) {
echo $out;
}
echo "Closing socket...";
socket_close ($socket);
echo "OK.\n\n";
?> |
|
- Table of Contents
- socket_accept -- Accepts a connection on a socket
- socket_bind -- Binds a name to a socket
- socket_close -- Closes a socket descriptor
- socket_connect -- Initiates a connection on a socket
- socket_listen -- Listens for a connection on a socket
- socket_read -- Read from a socket
- socket_create -- Create a socket (endpoint for communication)
- socket_strerror -- Return a string describing a socket error
- socket_write -- Write to a socket
- socket_fd_alloc -- Allocates a new file descriptor set
- socket_fd_free -- Deallocates a file descriptor set
- socket_fd_set -- Adds (a) file descriptor(s) to a set
- socket_fd_clear -- Clears (a) file descriptor(s) from a set
- socket_fd_isset -- Checks to see if a file descriptor is set within the file descrirptor set
- socket_fd_zero -- Clears a file descriptor set
- socket_select -- Runs the select() system call on the sets mentioned with a timeout specified by tv_sec and tv_usec
- socket_create_listen -- Opens a socket on port to accept connections
- socket_set_nonblock -- Sets nonblocking mode for file descriptor fd
- socket_getsockname -- Given an fd, stores a string representing sa.sin_addr and the value of sa.sin_port into addr and port describing the local side of a socket
- socket_getpeername -- Given an fd, stores a string representing sa.sin_addr and the value of sa.sin_port into addr and port describing the remote side of a socket
- socket_iovec_alloc -- ...]) Builds a 'struct iovec' for use with sendmsg, recvmsg, writev, and readv
- socket_iovec_fetch -- Returns the data held in the iovec specified by iovec_id[iovec_position]
- socket_iovec_set -- Sets the data held in iovec_id[iovec_position] to new_val
- socket_iovec_add -- Adds a new vector to the scatter/gather array
- socket_iovec_delete -- Deletes a vector from an array of vectors
- socket_iovec_free -- Frees the iovec specified by iovec_id
- socket_readv -- Reads from an fd, using the scatter-gather array defined by iovec_id
- socket_writev -- Writes to a file descriptor, fd, using the scatter-gather array defined by iovec_id
- socket_recv -- Receives data from a connected socket
- socket_send -- Sends data to a connected socket
- socket_recvfrom -- Receives data from a socket, connected or not
- socket_sendto -- Sends a message to a socket, whether it is connected or not
- socket_recvmsg -- Used to receive messages on a socket, whether connection-oriented or not
- socket_sendmsg -- Sends a message to a socket, regardless of whether it is connection-oriented or not
- socket_getopt -- Gets socket options for the socket
- socket_setopt -- |array optval) Sets socket options for the socket
- socket_create_pair -- Creates a pair of indistinguishable sockets and stores them in fds.
- socket_shutdown -- Shuts down a socket for receiving, sending, or both.
- socket_last_error -- Returns/Clears the last error on the socket