mb_encode_mimeheader

(PHP 4 >= 4.0.6, PHP 5)

mb_encode_mimeheaderEncode string for MIME header

Opis

string mb_encode_mimeheader ( string $str [, string $charset [, string $transfer_encoding [, string $linefeed = "\r\n" [, int $indent = 0 ]]]] )

Encodes a given string str by the MIME header encoding scheme.

Parametry

str

The string being encoded.

charset

charset specifies the name of the character set in which str is represented in. The default value is determined by the current NLS setting (mbstring.language). mb_internal_encoding() should be set to same encoding.

transfer_encoding

transfer_encoding specifies the scheme of MIME encoding. It should be either "B" (Base64) or "Q" (Quoted-Printable). Falls back to "B" if not given.

linefeed

linefeed specifies the EOL (end-of-line) marker with which mb_encode_mimeheader() performs line-folding (a » RFC term, the act of breaking a line longer than a certain length into multiple lines. The length is currently hard-coded to 74 characters). Falls back to "\r\n" (CRLF) if not given.

indent

Indentation of the first line (number of characters in the header before str).

Zwracane wartości

A converted version of the string represented in ASCII.

Rejestr zmian

Wersja Opis
5.0.0 The indent parameter was added.

Przykłady

Przykład #1 mb_encode_mimeheader() example

<?php
$name 
""// kanji
$mbox "kru";
$doma "gtinn.mon";
$addr mb_encode_mimeheader($name"UTF-7""Q") . " <" $mbox "@" $doma ">";
echo 
$addr;
?>

Notatki

Informacja:

This function isn't designed to break lines at higher-level contextual break points (word boundaries, etc.). This behaviour may clutter up the original string with unexpected spaces.

Zobacz też:

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User Contributed Notes 12 notes

up
3
Anonymous
5 years ago
I could not find a PHP function to MIME encode the name for a n email address.

Input   = "Karl Müller<kmueller@gmx.de>"
Output = "Karl%20M%FCller<kmueller@gmx.de>"

I wrote it on my own:

<?php
// required to encode names in email addresses   
// replace " " with "%20"
// replace "ü" with "%FC"
// replace "%" with "%25"      etc....
// Use "%" as Delimiter for MIME
// Use "=" as Delimiter for Quoted Printable
// Input string must be UTF8 encoded
public static function EncodeMime($Text, $Delimiter)
{
   
$Text = utf8_decode($Text);
   
$Len  = strlen($Text);
   
$Out  = "";
    for (
$i=0; $i<$Len; $i++)
    {
       
$Chr = substr($Text, $i, 1);
       
$Asc = ord($Chr);

        if (
$Asc > 0x255) // Unicode not allowed
       
{
           
$Out .= "?";
        }
        else if (
$Chr == " " || $Chr == $Delimiter || $Asc > 127)
        {
           
$Out .= $Delimiter . strtoupper(bin2hex($Chr));
        }
        else
$Out .= $Chr;
    }
    return
$Out;
}
?>
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2
gullevek at gullevek dot org
11 years ago
Read this FIRST: http://bugs.php.net/bug.php?id=23192 because mb_encode_mimeheaders is BUGGY!

a work around for the multibyte broken error for too long subjects for ISO-2022-JP:

$pos=0;
$split=36; // after 36 single bytes characters, if then comes MB, it is broken
while ($pos<mb_strlen($string,$encoding))
{
  $output=mb_strimwidth($string,$pos,$split,"",$encoding);
  $pos+=mb_strlen($output,$encoding);
  $_string.=(($_string)?' ':'').mb_encode_mimeheader($output,$encoding);
}
$string=$_string;

is not the best, but it works
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1
tokul at users dot sourceforge dot net
6 years ago
mb_encode_mimeheader() depends on correct mbstring.internal_encoding setting. It tries to convert $str from internal encoding to $charset. If you ignore mbstring internal encoding, function might encode strings incorrectly even when $str character set matches $charset
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1
stormflyCUT at hyh dot pl
8 years ago
Some solution for using national chars and have problem with UTF-8 for example in mail subject. Before you use mb_encode_mimeheader with UTF-8 set mb_internal_encoding('UTF-8').
up
1
chappy at citromail dot hu
8 years ago
In countries where there's non-us ASCII, it's a very good example, for sending mail:

mb_internal_encoding('iso-8859-2');
setlocale(LC_CTYPE, 'hu_HU');

function encode($str,$charset){
    $str=mb_encode_mimeheader(trim($str),$charset, 'Q', "\n\t");
    return $str;
}

print encode('the text with spec. chars: &#337; &#368; &#336; &#369;, ','iso-8859-2');

It creates a 7bit string
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0
chappy at citromail dot hu
8 years ago
I found a bad function.

<?php
function encodeHeader($input, $charset = 'ISO-8859-2')
{
   
preg_match_all('/(\\w*[\\x80-\\xFF]+\\w*)/', $input, $matches);
    foreach (
$matches[1] as $value) {
       
$replacement = preg_replace('/([\\x80-\\xFF])/e', '"=" . strtoupper(dechex(ord("\\1")))', $value);
       
$input = str_replace($value, '=?' . $charset . '?Q?' . $replacement . '?=', $input);
    }
    return
$input;
}
?>

This function should be used:

<?php
function encodeHeader($input, $charset = 'ISO-8859-2')
{
   
$m=preg_match_all('/(\w*[\x80-\xFF]+\w*)/', $input, $matches);
    if(
$m)$input=mb_encode_mimeheader($input,$charset, 'Q');
    return
$input;
}
?>
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0
paravoid
8 years ago
If mb_ version doesn't work for you in MIME-B mode:

function encode_mimeheader($string, $charset=null, $linefeed="\r\n") {
    if (!$charset)
        $charset = mb_internal_encoding();

    $start = "=?$charset?B?";
    $end = "?=";
    $encoded = '';

    /* Each line must have length <= 75, including $start and $end */
    $length = 75 - strlen($start) - strlen($end);
    /* Average multi-byte ratio */
    $ratio = mb_strlen($string, $charset) / strlen($string);
    /* Base64 has a 4:3 ratio */
    $magic = $avglength = floor(3 * $length * $ratio / 4);

    for ($i=0; $i <= mb_strlen($string, $charset); $i+=$magic) {
        $magic = $avglength;
        $offset = 0;
        /* Recalculate magic for each line to be 100% sure */
        do {
            $magic -= $offset;
            $chunk = mb_substr($string, $i, $magic, $charset);
            $chunk = base64_encode($chunk);
            $offset++;
        } while (strlen($chunk) > $length);
        if ($chunk)
            $encoded .= ' '.$start.$chunk.$end.$linefeed;
    }
    /* Chomp the first space and the last linefeed */
    $encoded = substr($encoded, 1, -strlen($linefeed));

    return $encoded;
}
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0
nigrez at nius dot waw dot pl
8 years ago
True, function is broken (PHP5.1, encoding from UTF-8 with pl_PL charset). Below is about 15% faster version of proposed _mb_mime_encode. Also it has header more like othe mb_* functions and doesn't trigger any errors/warnings/notices.

<?php

function mb_mime_header($string, $encoding=null, $linefeed="\r\n") {
  if(!
$encoding) $encoding = mb_internal_encoding();
 
$encoded = '';

  while(
$length = mb_strlen($string)) {
   
$encoded .= "=?$encoding?B?"
            
. base64_encode(mb_substr($string,0,24,$encoding))
             .
"?=$linefeed";

   
$string = mb_substr($string,24,$length,$encoding);
  }

  return
$encoded;
}

?>
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0
iwakura at junx dot org
9 years ago
i think mb_encode_mimeheader still have bug. here is sample code:

function mb_encode_mimeheader2($string, $encoding = "ISO-2022-JP") {
    $string_array = array();
    $pos = 0;
    $row = 0;
    $mode = 0;
   
    while ($pos < mb_strlen($string)) {
        $word = mb_strimwidth($string, $pos, 1);
        if (!$word) {
            $word = mb_strimwidth($string, $pos, 2);
        }
        if (mb_ereg_match("[ -~]", $word)) {    // ascii
            if ($mode != 1) {
                $row++;
                $mode = 1;
                $string_array[$row] = NULL;
            }
        } else {                                // multibyte
            if ($mode != 2) {
                $row++;
                $mode = 2;
                $string_array[$row] = NULL;
            }
        }
        $string_array[$row] .= $word;
        $pos++;
    }
   
    //echo "<pre>";
    //print_r($string_array);
    //echo "</pre>";
   
    foreach ($string_array as $key => $value) {
        $value = mb_convert_encoding($value, $encoding);
        $string_array[$key] = mb_encode_mimeheader($value, $encoding);
    }
   
    //echo "<pre>";
    //print_r($string_array);
    //echo "</pre>";
   
    return implode("", $string_array);
}

is not the best, but it works
up
0
mortoray at ecircle-ag dot com
9 years ago
At least for Q encoding, this function is unsafe and does not encode correctly. Raw characters which appear as RFC2047 sequences are simply left as is.

Ex:

mb_encode_mimeheader( '=?iso-8859-1?q?this=20is=20some=20text?=' );

returns '=?iso-8859-1?q?this=20is=20some=20text?='

The exact same string, which is obviously not the encoding for the source string.  That is, mb_encode_mimeheader does not do any type of escaping.

That is, the following condition is not always true:
    mb_decode_mimeheader( mb_encode_mimeheader( $text ) ) == $text
up
-1
gullevek at gullevek dot org
8 years ago
My first post was around 2003, and still the mb_mime_header is broken. It is *NOT* usable with longer subjects, and mostly unusable with anything else than japanese.

iwakura at junx dot org is also not working for me, it produces also some gargabe.

I updated my old function (the one I posted 2003) and I tested it with overlong subjects in UTF-8, ISO-2022-JP (japanese), GB2312 (simplified chinese) and EUC-KR (korean) and I got readable results in thunderbird, mail.app, outlook, etc.

<?php

function _mb_mime_encode($string, $encoding)
{
   
$pos = 0;
   
// after 36 single bytes characters if then comes MB, it is broken
    // but I trimmed it down to 24, to stay 100% < 76 chars per line
   
$split = 24;
    while (
$pos < mb_strlen($string, $encoding))
    {
       
$output = mb_strimwidth($string, $pos, $split, "", $encoding);
       
$pos += mb_strlen($output, $encoding);
       
$_string_encoded = "=?".$encoding."?B?".base64_encode($output)."?=";
        if (
$_string)
           
$_string .= "\r\n";
       
$_string .= $_string_encoded;
    }
   
$string = $_string;
    return
$string;
}

?>
up
-2
masataka
11 years ago
second parameter 'charset' is character encoding name, but default must be UTF-8 on PHP4.3.1.
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