Socket context options
Socket context option listing
Description
Socket context options are available for all wrappers that work over
sockets, like tcp, http and
ftp.
Options
bindto-
Used to specify the IP address (either IPv4 or IPv6) and/or the
port number that PHP will use to access the network. The syntax
is ip:port for IPv4 addresses, and
[ip]:port for IPv6 addresses.
Setting the IP or the port to 0 will let the system
choose the IP and/or port.
Note:
As FTP creates two socket connections during normal operation,
the port number cannot be specified using this option.
backlog-
Used to limit the number of outstanding connections in the
socket's listen queue.
Note:
This is only applicable to stream_socket_server.
ipv6_v6only-
Overrides the OS default regarding mapping IPv4 into IPv6.
Note:
This is important in particular when trying to listen on IPv4 addresses
separately while there exists a binding on [::].
This is only applicable to stream_socket_server.
so_reuseport-
Allows multiple bindings to a same ip:port pair, even from separate processes.
Note:
This is only applicable to stream_socket_server.
so_broadcast-
Enables sending and receiving data to/from broadcast addresses.
Note:
This is only applicable to stream_socket_server.
Examples
Example #1 Basic bindto usage example
<?php
// connect to the internet using the '192.168.0.100' IP
$opts = array(
'socket' => array(
'bindto' => '192.168.0.100:0',
),
);
// connect to the internet using the '192.168.0.100' IP and port '7000'
$opts = array(
'socket' => array(
'bindto' => '192.168.0.100:7000',
),
);
// connect to the internet using the '2001:db8::1' IPv6 address
// and port '7000'
$opts = array(
'socket' => array(
'bindto' => '[2001:db8::1]:7000',
),
);
// connect to the internet using port '7000'
$opts = array(
'socket' => array(
'bindto' => '0:7000',
),
);
// create the context...
$context = stream_context_create($opts);
// ...and use it to fetch the data
echo file_get_contents('http://www.example.com', false, $context);
?>