imap_fetchheader
(PHP 4, PHP 5, PHP 7)
imap_fetchheader — Returns header for a message
说明
   imap_fetchheader
    ( resource 
  $imap_stream
   , int $msg_number
   [, int $options = 0
  ] ) : stringThis function causes a fetch of the complete, unfiltered » RFC2822 format header of the specified message.
参数
- 
imap_stream
- 
由 imap_open() 返回的 IMAP 流。 
- 
msg_number
- 
      The message number 
- 
options
- 
      The possible optionsare:- 
         
          FT_UID- Themsgnoargument 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.