IMAP 函数
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imap_mime_header_decode

(PHP 4, PHP 5)

imap_mime_header_decode — Decode MIME header elements

说明

array imap_mime_header_decode ( string $text )

Decodes MIME message header extensions that are non ASCII text (see » RFC2047).

参数

text

The MIME text

返回值

The decoded elements are returned in an array of objects, where each object has two properties, charset and text.

If the element hasn't been encoded, and in other words is in plain US-ASCII, the charset property of that element is set to default.

范例

Example #1 imap_mime_header_decode() example

<?php
$text = "=?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld@example.com>";

$elements = imap_mime_header_decode($text);
for ($i=0; $i<count($elements); $i++) {
    echo "Charset: {$elements[$i]->charset}\n";
    echo "Text: {$elements[$i]->text}\n\n";
}
?>

以上例程会输出：

Charset: ISO-8859-1
Text: Keld J?rn Simonsen

Charset: default
Text:  <keld@example.com>

In the above example we would have two elements, whereas the first element had previously been encoded with ISO-8859-1, and the second element would be plain US-ASCII.

参见

IMAP 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: Decode MIME header elements

用户评论:

kai at froghh dot de (04-Aug-2008 05:25)

Beware of multilined subjects containing whitespaces which are not part of the subject itself, but needed as functional characters for the clients.

i.e. you can have a mail header containing content like
Subject: =?iso-8859-1?Q?WG=3A_Mobilit=E4t_verschlechtert_--=3E_174?=
    =?iso-8859-1?Q?6?=

(carriage return and tabspace).
imap_mime_header_decode returns 5 parts (and not expected 2)
for this example.
- The first containing the space between "subject:" and the subject itself.
- The second is the first encoded text
- The third will be the line-break within the head lines.
The were inserted to keep rfc compliant line length and are NOT part of the original subject entered by the sender.
- The fourth will be the second part of the subject.
- The fifth is a line break - the last character will be a line break any time other head lines or mailbody will follow, so it's needed in the head - but not part of the original subject.

s dot wiese at trabia dot md (18-Dec-2007 09:46)

The example of diego is working well, he has a (very) little
mistake in his code. Here is the corrected version:

<?php
//return supported encodings in lowercase.
function mb_list_lowerencodings() { $r=mb_list_encodings();
  for ($n=sizeOf($r); $n--; ) { $r[$n]=strtolower($r[$n]); } return $r;
}

//  Receive a string with a mail header and returns it
// decoded to a specified charset.
// If the charset specified into a piece of text from header
// isn't supported by "mb", the "fallbackCharset" will be
// used to try to decode it.
function decodeMimeString($mimeStr, $inputCharset='utf-8', $targetCharset='utf-8', $fallbackCharset='iso-8859-1') {
  $encodings=mb_list_lowerencodings();
  $inputCharset=strtolower($inputCharset);
  $targetCharset=strtolower($targetCharset);
  $fallbackCharset=strtolower($fallbackCharset);

  $decodedStr='';
  $mimeStrs=imap_mime_header_decode($mimeStr);
  for ($n=sizeOf($mimeStrs), $i=0; $i<$n; $i++) {
    $mimeStr=$mimeStrs[$i];
    $mimeStr->charset=strtolower($mimeStr->charset);
    if (($mimeStr == 'default' && $inputCharset == $targetCharset)
      || $mimStr->charset == $targetCharset) {
      $decodedStr.=$mimStr->text;
    } else {
      $decodedStr.=mb_convert_encoding(
        $mimeStr->text, $targetCharset,
        (in_array($mimeStr->charset, $encodings) ?
          $mimeStr->charset : $fallbackCharset)
        )
      );
    }
  } return $decodedStr;
}
?>

diego nunes <dn at nospam dot dnunes dot com> (14-Dec-2006 06:12)

The previous comment (from hans) seems to make no sense at all, since it will not change the encoding and possibly result in a "multiencoding" string (that the browser and anything else will be unable to render, of course).

    I use a little function to decode the whole header to a specified encoding. It is as follow:

<?php
//return supported encodings in lowercase.
function mb_list_lowerencodings() { $r=mb_list_encodings();
  for ($n=sizeOf($r); $n--; ) { $r[$n]=strtolower($r[$n]); } return $r;
}

//  Receive a string with a mail header and returns it
// decoded to a specified charset.
// If the charset specified into a piece of text from header
// isn't supported by "mb", the "fallbackCharset" will be
// used to try to decode it.
function decodeMimeString($mimeStr, $inputCharset='utf-8', $targetCharset='utf-8', $fallbackCharset='iso-8859-1') {
  $encodings=mb_list_lowerencodings();
  $inputCharset=strtolower($inputCharset);
  $targetCharset=strtolower($targetCharset);
  $fallbackCharset=strtolower($fallbackCharset);

  $decodedStr='';
  $mimeStrs=imap_mime_header_decode($mimeStr);
  for ($n=sizeOf($mimeStrs), $i=0; $i<$n; $i++) {
    $mimeStr=$mimeStrs[$i];
    $mimeStr->charset=strtolower($mimeStr->charset);
    if (($mimeStr == 'default' && $inputCharset == $targetCharset)
      || $mimStr->charset == $targetCharset) {
      $decodedStr.=$mimStr->text;
    } else {
      $decodedStr.=mb_convert_encoding(
        $mimeStr->text, $targetCharset,
        (in_array($mimeStr->charset, $encodings) ?
          $mimeStr->charset : $fallbackCharset)
        )
      );
    }
  } return $decodedStr;
}
?>

    Hope it helps.

hans at lintoo dot dk (22-Dec-2005 02:10)

This is obvious, but nevertheless here is a "flat" version:
<?php   
private function flatMimeDecode($string) {
    $array = imap_mime_header_decode($string);
    $str = "";
    foreach ($array as $key => $part) {
        $str .= $part->text;
    }
    return $str;
}
?>

cracker at bigcracker dot ca (22-Feb-2005 12:55)

In response to Sven dot Dickert at planb dot de: if you encounter problems with "=?utf-8?Q?" appearing in your headers, I found that simply using "imap_utf8($string)" decoded the "$string" properly and solved my problem perfectly.

Pawel Tomicki <pafka at klub dot chip dot pl> (22-Apr-2004 07:04)

<?php

function decode_iso88591($string){
  if (strpos(strtolower($string), '=?iso-8859-1') === false) {
    return $string;
  }
  $string = explode('?', $string);
  return strtolower($string[2]) == 'q' ? quoted_printable_decode($string[3]) : base64_decode($string[3]);
}

?>

mattias at forss dot se (27-Nov-2003 03:45)

This function does not code a-z 0-9 like the function posted by bandpay at hotmail dot com

function encode_iso88591($string) {
    if( ereg("[^A-Za-z0-9\ ]", $string) ) {
        $text = "=?iso-8859-1?q?";
        for( $i = 0 ; $i < strlen($string) ; $i++ ) {
            if( ereg("[^A-Za-z0-9]", $string[$i]) ) {
                $text .= "=".dechex(ord($string[$i]));
            } else {
                $text .= $string[$i];
            }
        }
        return $text."?=";
    } else     return $string;
}

hdlim at kis21 dot com (01-Jan-2003 06:35)

imap_mime_header_decode, utf-7 and utf-8 problem, i solved the problem using below function. note that iconv function for code converting.
you must replace "EUC-KR" as iconv parameter with charset you want such as "iso-8859-1".

function mime_decode($s) {
  $elements = imap_mime_header_decode($s);
  for($i = 0;$i < count($elements);$i++) {
    $charset = $elements[$i]->charset;
    $text =$elements[$i]->text;
    if(!strcasecmp($charset, "utf-8") ||
       !strcasecmp($charset, "utf-7"))
    {
      $text = iconv($charset, "EUC-KR", $text);
    }
    $decoded = $decoded . $text;
  }
  return $decoded;
}

Sven dot Dickert at planb dot de (16-May-2002 02:31)

Beware! imap_mime_header_decode in 4.0.6 is _not_ RFC2047 conform. The string =?utf-7?Q?Petra_M+APw-ller?= will not converted into Petra Mller cause the charset utf7 is unknown.  Same goes to =?utf-8?Q?Petra_M=C3=BCller?= for charset utf8.

charsyam at liso dot cs dot pusan dot ac dot kr (13-Aug-2001 04:34)

I wrote a simple ks_c_5601-1987(2byte)
encode

function encode_ksc5601( $string )
{
 $encode = base64_encode( $string );
 $text = "=?ks_c_5601-1987?B?";
 $text = $text.$encode."?=";
 return $text;
}