PHP: socket_bind - Manual (original) (raw)

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

socket_bind — Binds a name to a socket

Description

Parameters

socket

A Socket instance created with socket_create().

address

If the socket is of the [AF_INET](sockets.constants.php#constant.af-inet) family, theaddress is an IP in dotted-quad notation (e.g. 127.0.0.1).

If the socket is of the [AF_UNIX](sockets.constants.php#constant.af-unix) family, theaddress 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](sockets.constants.php#constant.af-inet) socket, and designates the port on which to listen for connections.

Changelog

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);?>

See Also

• socket_connect() - Initiates a connection on a socket
• socket_listen() - Listens for a connection on a socket
• socket_create() - Create a socket (endpoint for communication)
• socket_last_error() - Returns the last error on the socket
• socket_strerror() - Return a string describing a socket error

Found A Problem?

keksov[at]gmx.de ¶

23 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!

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

php50613160534 dot 3 dot korkman at spamgourmet dot org ¶

20 years ago

Use 0 for port to bind a random (free) port for incoming connections:

socket_bind ($socket, $bind_address, 0);
socket_getsockname($socket, <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>s</mi><mi>o</mi><mi>c</mi><mi>k</mi><mi>e</mi><msub><mi>t</mi><mi>a</mi></msub><mi>d</mi><mi>d</mi><mi>r</mi><mi>e</mi><mi>s</mi><mi>s</mi><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">socket_address, </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">soc</span><span class="mord mathnormal" style="margin-right:0.03148em;">k</span><span class="mord mathnormal">e</span><span class="mord"><span class="mord mathnormal">t</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal">dd</span><span class="mord mathnormal">ress</span><span class="mpunct">,</span></span></span></span>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.

ealexs at gmail dot com ¶

3 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);

?>

gasket at cekkent dot net ¶

22 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.

gabriel at plenitech dot fr ¶

12 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);
?>