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    socket_bind

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

    socket_bind — Binds a name to a socket

    Description

    function 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
    8.5.0 Now throws a ValueError when port is lower than 0 or greater than 65535.
    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().

    See Also

    Found A Problem?

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
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    User Contributed Notes 6 notes

    up
    19
    keksov[at]gmx.de
    24 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!
    up
    10
    dresende at thinkdigital dot pt
    14 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
    up
    5
    php50613160534 dot 3 dot korkman at spamgourmet dot org
    21 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.
    up
    2
    ealexs at gmail dot com
    4 years ago
    I am posting this as I've spent a few hours debugging this.

If you use socket_create / socket_bind with Unix domain sockets, then using socket_close at the end is not sufficient. You will get "address already in use" the second time you run your script. Call unlink on the file that is used for Unix domain sockets, preferably before you start to create the socket.

<?php

$socket_file = "./test.sock";

if (file_exists($socket_file))
        unlink($socket_file);
# optional file lock
$socket = socket_create(AF_UNIX, SOCK_STREAM, 0);
# ... socket_set_option ...
socket_bind($socket, $socket_file);
# ...
socket_close($socket);
# optional : release lock
unlink($socket_file);

?>
    up
    0
    gasket at cekkent dot net
    23 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.
    up
    -3
    gabriel at plenitech dot fr
    13 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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