stream_socket_server

(PHP 5)

stream_socket_server --  Create an Internet or Unix domain server socket

Description

resource stream_socket_server ( string local_socket [, int &errno [, string &errstr [, int flags [, resource context]]]] )

Creates a stream or datagram socket on the specified local_socket. The type of socket created is determined by the transport specified using standard URL formatting: transport://target. For Internet Domain sockets (AF_INET) such as TCP and UDP, the target portion of the remote_socket parameter should consist of a hostname or IP address followed by a colon and a port number. For Unix domain sockets, the target portion should point to the socket file on the filesystem. flags is a bitmask field which may be set to any combination of socket creation flags. The default value of flags is STREAM_SERVER_BIND | STREAM_SERVER_LISTEN.

Note: For UDP sockets, you must use STREAM_SERVER_BIND as the flags parameter.

This function only creates a socket, to begin accepting connections use stream_socket_accept().

If the call fails, it will return FALSE and if the optional errno and errstr arguments are present they will be set to indicate the actual system level error that occurred in the system-level socket(), bind(), and listen() calls. If the value returned in errno is 0 and the function returned FALSE, it is an indication that the error occurred before the bind() call. This is most likely due to a problem initializing the socket. Note that the errno and errstr arguments will always be passed by reference.

Depending on the environment, Unix domain sockets may not be available. A list of available transports can be retrieved using stream_get_transports(). See Appendix P for a list of bulitin transports.

Example 1. Using TCP server sockets

<?php
$socket
= stream_socket_server("tcp://0.0.0.0:8000", $errno, $errstr);
if (!
$socket) {
  echo
"$errstr ($errno)<br />\n";
} else {
  while (
$conn = stream_socket_accept($socket)) {
    
fwrite($conn, 'The local time is ' . date('n/j/Y g:i a') . "\n");
    
fclose($conn);
  }
  
fclose($socket);
}
?>

The example below shows how to act as a time server which can respond to time queries as shown in an example on stream_socket_client().

Note: Most systems require root access to create a server socket on a port below 1024.

Example 2. Using UDP server sockets

<?php
$socket
= stream_socket_server("udp://127.0.0.1:1113", $errno, $errstr, STREAM_SERVER_BIND);
if (!
$socket) {
    die(
"$errstr ($errno)");
}

do {
    
$pkt = stream_socket_recvfrom($socket, 1, 0, $peer);
    echo
"$peer\n";
    
stream_socket_sendto($socket, date("D M j H:i:s Y\r\n"), 0, $peer);
} while (
$pkt !== false);

?>

Note: When specifying a numerical IPv6 address (e.g. fe80::1) you must enclose the IP in square brackets. For example, tcp://[fe80::1]:80.

See also stream_socket_client(), stream_set_blocking(), stream_set_timeout(), fgets(), fgetss(), fwrite(), fclose(), feof(), and the Curl extension.