socket_bind

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

socket_bindBinds a name to a socket

Description

socket_bind(Socket $socket, string $address, int $port = 0): bool

Binds the name given in address to the socket described by socket. This has to be done before a connection is established using socket_connect() or socket_listen().

Parameters

socket

A Socket instance created with socket_create().

address

If the socket is of the AF_INET family, the address is an IP in dotted-quad notation (e.g. 127.0.0.1).

If the socket is of the AF_UNIX family, the address is the path of a Unix-domain socket (e.g. /tmp/my.sock).

port (Optional)

The port parameter is only used when binding an AF_INET socket, and designates the port on which to listen for connections.

Return Values

Returns true on success or false on failure.

The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.

Changelog

Version Description
8.0.0 socket is a Socket instance now; previously, it was a resource.

Examples

Example #1 Using socket_bind() to set the source address

<?php
// Create a new socket
$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

// An example list of IP addresses owned by the computer
$sourceips['kevin'] = '127.0.0.1';
$sourceips['madcoder'] = '127.0.0.2';

// Bind the source address
socket_bind($sock, $sourceips['madcoder']);

// Connect to destination address
socket_connect($sock, '127.0.0.1', 80);

// Write
$request = 'GET / HTTP/1.1' . "\r\n" .
'Host: example.com' . "\r\n\r\n";
socket_write($sock, $request);

// Close
socket_close($sock);

?>

Notes

Note:

This function must be used on the socket before socket_connect().

Note:

Windows 9x/ME compatibility note: socket_last_error() may return an invalid error code if trying to bind the socket to a wrong address that does not belong to your machine.

See Also

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User Contributed Notes 6 notes

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8
dresende at thinkdigital dot pt
12 years ago
Regarding previous post:

"0" has address is no different from "0.0.0.0"

127.0.0.1 -> accept only from local host
w.x.y.z (valid local IP) -> accep only from this network
0.0.0.0 -> accept from anywhere
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12
keksov[at]gmx.de
21 years ago
If you want to reuse address and port, and get rid of error: unable to bind, address already in use, you have to use socket_setopt (check actual spelling for this function in you PHP verison) before calling bind:

<?php
if (!socket_set_option($sock, SOL_SOCKET, SO_REUSEADDR, 1)) {
    echo
socket_strerror(socket_last_error($sock));
    exit;
}
?>

This solution was found by
Christophe Dirac. Thank you Christophe!
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3
php50613160534 dot 3 dot korkman at spamgourmet dot org
18 years ago
Use 0 for port to bind a random (free) port for incoming connections:

socket_bind ($socket, $bind_address, 0);
socket_getsockname($socket, $socket_address, $socket_port);
socket_listen($socket);
...

$socket_port contains the assigned port, you might want to send it to a remote client connecting. Tested with php 5.03.
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2
gasket at cekkent dot net
20 years ago
The aforementioned tidbit about using NULL to bind to all addresses did not work for me, as I would receive an error about unknown address. Using a 0 worked for me:

socket_bind ($socket, 0, $port)

This also allows you to receive UDP broadcasts, which is what I had been trying to figure out.
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-2
gabriel at plenitech dot fr
10 years ago
When doing Unix sockets, it might be necessary to chmod the socket file so as to give Write permission to Group and/or Others. Otherwise, only the owner is allowed to write data into the stream.

Example:

<?php
$sockpath
= '/tmp/my.sock';
socket_bind($socket, $sockpath);
//here: write-only (socket_send) to others, only owner can fetch data.
chmod($sockpath, 0702);
?>
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-11
Mex
12 years ago
It appears for the $address parameter:

'127.0.0.1'
accepts clients from localhost (eg. 127.0.0.1)

'0.0.0.0'
accepts clients from localhost, and the server's network (eg. 127.0.0.1, 192.168.2.5, 10.20.30.40)

'0' or 0
accepts clients from localhost, the server's network, and external networks (eg. 127.0.0.1, 192.168.2.5, 10.20.30.40, 209.85.169.99)
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