socket_bind
(PHP 4 >= 4.1.0, PHP 5)
socket_bind — Binds a name to a socket
Description
$socket
, string $address
[, int $port = 0
] )
Binds the name given in address to the socket
described by socket. This has to be done before
a connection is be established using socket_connect()
or socket_listen().
Parameters
-
socket -
A valid socket resource created with socket_create().
-
address -
If the socket is of the
AF_INETfamily, theaddressis an IP in dotted-quad notation (e.g. 127.0.0.1).If the socket is of the
AF_UNIXfamily, theaddressis the path of a Unix-domain socket (e.g. /tmp/my.sock). -
port(Optional) -
The
portparameter is only used when binding anAF_INETsocket, 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.
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
- 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
- socket_accept
- socket_bind
- socket_clear_error
- socket_close
- socket_cmsg_space
- socket_connect
- socket_create_listen
- socket_create_pair
- socket_create
- socket_get_option
- socket_getopt
- socket_getpeername
- socket_getsockname
- socket_import_stream
- socket_last_error
- socket_listen
- socket_read
- socket_recv
- socket_recvfrom
- socket_recvmsg
- socket_select
- socket_send
- socket_sendmsg
- socket_sendto
- socket_set_block
- socket_set_nonblock
- socket_set_option
- socket_setopt
- socket_shutdown
- socket_strerror
- socket_write
Коментарии
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!
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, $port)
This also allows you to receive UDP broadcasts, which is what I had been trying to figure out.
Use 0 for port to bind a random (free) port for incoming connections:
socket_bind ($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.
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
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);
?>
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);
?>