imap_fetchheader
(PHP 4, PHP 5, PHP 7, PHP 8)
imap_fetchheader — Returns header for a message
说明
imap_fetchheader
( resource
$imap
, int $message_num
, int $flags
= 0
) : string|falseThis function causes a fetch of the complete, unfiltered » RFC2822 format header of the specified message.
参数
-
imap
-
由 imap_open() 返回的 IMAP 流。
-
message_num
-
The message number
-
flags
-
The possible
flags
are:-
FT_UID
- Themessage_num
argument is a UID -
FT_INTERNAL
- The return string is in "internal" format, without any attempt to canonicalize to CRLF newlines -
FT_PREFETCHTEXT
- The RFC822.TEXT should be pre-fetched at the same time. This avoids an extra RTT on an IMAP connection if a full message text is desired (e.g. in a "save to local file" operation)
-
返回值
Returns the header of the specified message as a text string, 或者在失败时返回 false
.