PHP 7.0.6 Released

socket_create_pair

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

socket_create_pairCreates a pair of indistinguishable sockets and stores them in an array

Description

bool socket_create_pair ( int $domain , int $type , int $protocol , array &$fd )

socket_create_pair() creates two connected and indistinguishable sockets, and stores them in fd. This function is commonly used in IPC (InterProcess Communication).

Parameters

domain

The domain parameter specifies the protocol family to be used by the socket. See socket_create() for the full list.

type

The type parameter selects the type of communication to be used by the socket. See socket_create() for the full list.

protocol

The protocol parameter sets the specific protocol within the specified domain to be used when communicating on the returned socket. The proper value can be retrieved by name by using getprotobyname(). If the desired protocol is TCP, or UDP the corresponding constants SOL_TCP, and SOL_UDP can also be used.

See socket_create() for the full list of supported protocols.

fd

Reference to an array in which the two socket resources will be inserted.

Return Values

Returns TRUE on success or FALSE on failure.

Changelog

Version Description
5.3.0 This function is now re-enabled on Windows platforms.
4.3.0 This function was due to a bug made unavailable on Windows platforms.

Examples

Example #1 socket_create_pair() example

<?php
$sockets 
= array();

/* On Windows we need to use AF_INET */
$domain = (strtoupper(substr(PHP_OS03)) == 'WIN' AF_INET AF_UNIX);

/* Setup socket pair */
if (socket_create_pair($domainSOCK_STREAM0$sockets) === false) {
    echo 
"socket_create_pair failed. Reason: ".socket_strerror(socket_last_error());
}
/* Send and Recieve Data */
if (socket_write($sockets[0], "ABCdef123\n"strlen("ABCdef123\n")) === false) {
    echo 
"socket_write() failed. Reason: ".socket_strerror(socket_last_error($sockets[0]));
}
if ((
$data socket_read($sockets[1], strlen("ABCdef123\n"), PHP_BINARY_READ)) === false) {
    echo 
"socket_read() failed. Reason: ".socket_strerror(socket_last_error($sockets[1]));
}
var_dump($data);

/* Close sockets */
socket_close($sockets[0]);
socket_close($sockets[1]);
?>

Example #2 socket_create_pair() IPC example

<?php
$ary 
= array();
$strone 'Message From Parent.';
$strtwo 'Message From Child.';

if (
socket_create_pair(AF_UNIXSOCK_STREAM0$ary) === false) {
    echo 
"socket_create_pair() failed. Reason: ".socket_strerror(socket_last_error());
}
$pid pcntl_fork();
if (
$pid == -1) {
    echo 
'Could not fork Process.';
} elseif (
$pid) {
    
/*parent*/
    
socket_close($ary[0]);
    if (
socket_write($ary[1], $stronestrlen($strone)) === false) {
        echo 
"socket_write() failed. Reason: ".socket_strerror(socket_last_error($ary[1]));
    }
    if (
socket_read($ary[1], strlen($strtwo), PHP_BINARY_READ) == $strtwo) {
        echo 
"Recieved $strtwo\n";
    }
    
socket_close($ary[1]);
} else {
    
/*child*/
    
socket_close($ary[1]);
    if (
socket_write($ary[0], $strtwostrlen($strtwo)) === false) {
        echo 
"socket_write() failed. Reason: ".socket_strerror(socket_last_error($ary[0]));
    }
    if (
socket_read($ary[0], strlen($strone), PHP_BINARY_READ) == $strone) {
        echo 
"Recieved $strone\n";
    }
    
socket_close($ary[0]);
}
?>

See Also

User Contributed Notes

cweiske at php dot net
6 years ago
The underlying sockpair() function does only support AF_UNIX at least on BSD and Linux.
thegreatall at gmail dot com
8 years ago
There is a syntax error in one of the code samples provided, it should look like this:
<?php
$sockets
= array();
/* Setup socket pair */
if (socket_create_pair(AF_UNIX, SOCK_STREAM, 0, $sockets) === false) {
    echo
"socket_create_pair failed. Reason: ".socket_strerror(socket_last_error());
}
/* Send and Recieve Data */
if (socket_write($sockets[0], "ABCdef123\n", strlen("ABCdef123\n")) === false) {
    echo
"socket_write() failed. Reason: ".socket_strerror(socket_last_error($sockets[0]));
}
if ((
$data = socket_read($sockets[1], strlen("ABCdef123\n"), PHP_BINARY_READ)) === false) {
    echo
"socket_read() failed. Reason: ".socket_strerror(socket_last_error($sockets[1]));
}
var_dump($data);

/* Close sockets */
socket_close($sockets[0]);
socket_close($sockets[1]);
?>
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