PHP 7.0.6 Released

    socket_create_pair

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

    socket_create_pair — Creates 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_OS, 0, 3)) == 'WIN' ? AF_INET : AF_UNIX);

    /* Setup socket pair */
    if (socket_create_pair($domain, 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]);
    ?>

    Example #2 socket_create_pair() IPC example

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

    if (    socket_create_pair(AF_UNIX, SOCK_STREAM, 0, $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], $strone, strlen($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], $strtwo, strlen($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]);
    ?>
    To Top