imap_mime_header_decode

(PHP 4, PHP 5, PHP 7)

imap_mime_header_decodeDecode MIME header elements

说明

imap_mime_header_decode ( string $text ) : array

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

User Contributed Notes

alchrystal88 at web dot de 24-Jan-2019 11:43
If you have errors with wrong attachment names like this:

correct name:
String -> Prüfbericht Hersteller.pdf

fetchstructure object name:
 =?ISO-8859-1?Q?Pr=FCfbericht_Hersteller=2Epdf?=

Workaround to reconvert:

imap_mime_header_decode($fetchstructure->dparameters->value)[0]->text

imap_mime_header_decode($filename)[0]->text
paolo dot ceccacci at gmail dot com 24-Sep-2014 08:45
Here's a "flatMimeDecode" version converting UTF-8 to iso-8859-1:

function flatMimeDecode($string) {
        $array = imap_mime_header_decode ($string);
        $str = "";
        foreach ($array as $key => $part) {
            if($part->charset == "UTF-8"){
            $str .= utf8_decode ($part->text);
            }else{
            $str .= $part->text;
            }
        }
        return $str;
    }
Anonymous 04-Mar-2013 09:42
A nice way to decode strings is to use the mb_list_encodings(), but I had two problems with it:
sometimes, the charset is uppercase in the header an lowercase in mb_list_encodings() and sometimes, the charset is not in the mb_list_encodings() list.

<?php
function upperListEncode() { //convert mb_list_encodings() to uppercase
   
$encodes=mb_list_encodings();
    foreach (
$encodes as $encode) $tencode[]=strtoupper($encode);
    return
$tencode;
    }

function
decode($string) {
   
$tabChaine=imap_mime_header_decode($string);
   
$texte='';
    for (
$i=0; $i<count($tabChaine); $i++) {
       
        switch (
strtoupper($tabChaine[$i]->charset)) { //convert charset to uppercase
           
case 'UTF-8': $texte.= $tabChaine[$i]->text; //utf8 is ok
               
break;
            case
'DEFAULT': $texte.= $tabChaine[$i]->text; //no convert
               
break;
            default: if (
in_array(strtoupper($tabChaine[$i]->charset),upperListEncode())) //found in mb_list_encodings()
                       
{$texte.= mb_convert_encoding($tabChaine[$i]->text,'UTF-8',$tabChaine[$i]->charset);}
                     else {
//try to convert with iconv()
                         
$ret = iconv($tabChaine[$i]->charset, "UTF-8", $tabChaine[$i]->text);   
                          if (!
$ret) $texte.=$tabChaine[$i]->text//an error occurs (unknown charset)
                         
else $texte.=$ret;
                        }                   
                break;
            }
        }
       
    return
$texte;   
    }
?>
kai at froghh dot de 04-Aug-2008 09:25
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 01:46
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 10:12
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 06:10
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
$str;
}
?>
cracker at bigcracker dot ca 22-Feb-2005 04:55
In response to Sven dot Dickert at planb dot de: if you encounter problems with "=?utf-8?Q?" appearing in your headers, I found that simply using "imap_utf8($string)" decoded the "$string" properly and solved my problem perfectly.
Pawel Tomicki <pafka at klub dot chip dot pl> 22-Apr-2004 11:04
<?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 26-Nov-2003 07:45
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 10:35
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 06:31
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 M?ller 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 08:34
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;
}