# imap_ping

(PHP 4, PHP 5, PHP 7)

imap_ping — Check if the IMAP stream is still active

### 说明

imap_ping ( resource `$imap_stream` ) : bool

imap_ping() pings the stream to see if it's still active. It may discover new mail; this is the preferred method for a periodic "new mail check" as well as a "keep alive" for servers which have inactivity timeout.

### 参数

`imap_stream`

  由 imap_open() 返回的 IMAP 流。

### 返回值

Returns `TRUE` if the stream is still alive, `FALSE` otherwise.

### 范例

Example #1 imap_ping() Example

    <?php

    $imap = imap_open("{imap.example.org}", "mailadmin", "password");

    // after some sleeping
    if (!imap_ping($imap)) {
        // do some stuff to reconnect
    }

    ?>