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    Zookeeper::exists

    (PECL zookeeper >= 0.1.0)

    Zookeeper::exists — Checks the existence of a node in zookeeper synchronously

    说明

    public Zookeeper::exists(string $path, callable $watcher_cb = null): array

    参数

    path

    The name of the node. Expressed as a file name with slashes separating ancestors of the node.

    watcher_cb

    if nonzero, a watch will be set at the server to notify the client if the node changes. The watch will be set even if the node does not

    返回值

    Returns the value of stat for the path if the given node exists, otherwise false.

    错误／异常

    This method emits PHP error/warning when parameters count or types are wrong or fail to check the existence of a node.

    警告

    Since version 0.3.0, this method emits ZookeeperException and it's derivatives.

    示例

    示例 #1 Zookeeper::exists() example

    Check the existence of a node.

    <?php
    $zookeeper     = new Zookeeper('locahost:2181');
    $path = '/path/to/node';
    $r = $zookeeper->exists($path);
    if (    $r)
    echo     'EXISTS';
    else
    echo     'N/A or ERR';
    ?>

    以上示例会输出：

    EXISTS

    参见

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