IMAP 函数
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imap_uid

(PHP 4, PHP 5)

imap_uid — This function returns the UID for the given message sequence number

说明

int imap_uid ( resource $imap_stream , int $msg_number )

This function returns the UID for the given message sequence number. An UID is a unique identifier that will not change over time while a message sequence number may change whenever the content of the mailbox changes.

This function is the inverse of imap_msgno().

参数

imap_stream

由 imap_open() 返回的 IMAP 流。

msg_number

The message number.

返回值

The UID of the given message.

注释

Note:

This function is not supported by POP3 mailboxes.

参见

IMAP 函数
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PHP手册
PHP手册 - N: This function returns the UID for the given message sequence number

用户评论:

Maikel (15-Jul-2010 01:27)

Be aware that the uid is unique in a single mailbox. That means a message can have as much uids as mailboxes

anon et mouse (28-Jan-2009 07:57)

clarification for Andreas' note about imap_expunge()...

imap_expunge() does indeed change the UID, but only *after* the IMAP stream has closed and then reconnects.

You can use imap_expunge() as many times as you want within one IMAP stream (no reconnects) and the UID stays the same while the Msgno will change with imap_delete() followed by imap_expunge().

Andreas Seeger (24-Jul-2008 06:26)

The uid will change in case of unsing imap_expunge. Be shure that
all work ist done before using imap_expunge.

roger at sdr dot com dot au (02-May-2008 03:34)

A little quirk of UIDs in a PUBLIC folder in MDaemon (and perhaps other servers?). The UIDs may be unsynchronised between users if the server's option to store flags on a per-user basis is turned on. That is, a message may have a UID of 5 for one user (meaning it was the 5th message to enter the box) but 3 for another user (who perhaps subscribed to the box later). If this is a problem, turn off the per-user option for the mailbox.

steve_foley at excite dot com (05-Sep-2002 06:27)

Please note that message_id in the header is NOT the UID - and its dangerous to use as many mail progs don't put a message id in

robert dot blanch at hsc dot utah dot edu (17-Jul-2002 03:25)

Another way to get the UID without using imap_uid that works with pop3:

$header = imap_headerinfo( $mbox, $msgno );
$UID = $header->message_id;

(20-Jun-2002 09:53)

For those using a POP3 mailbox, this function, as noted, does not work.

One way around this is to use direct FTP communication with the mail server.  For example, the following function takes a mailbox/password and message sequence number, and from this returns the message UID.

function fetch_UID($account, $password, $message_number)
{
    $retval = 0;
    $fp = fsockopen($POPMAILSERVER, 110);
    if ($fp > 0)
    {
        $buf = fgets($fp, 1024);

        fputs($fp, "USER $account\r\n");
        $buf = fgets($fp, 1024);

        fputs($fp, "PASS $password\r\n");
        $buf = fgets($fp, 1024);

        fputs($fp, "UIDL $message_number\r\n");
        $retval=fgets($fp, 1024);

        fputs($fp, "QUIT\r\n");
        $buf = fgets($fp,1024);

        fclose($fp);
    }
    return substr($retval,6,30);
}

Note: 110 is the TCP port commonly associated with a POP3 mailbox.  Also the substr() function is used to trim the +OK and the message number from the beginning of the server's response.

I'm sure there are other (better) ways to do this.  But after a fruitless search of the internet, this is what I came up with, and it seems to work for me.