CascadiaPHP 2024

mb_encode_mimeheader

(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)

mb_encode_mimeheaderCodificar string para cabeçalho MIME

Descrição

mb_encode_mimeheader(
    string $string,
    ?string $charset = null,
    ?string $transfer_encoding = null,
    string $newline = "\r\n",
    int $indent = 0
): string

Codifica uma string string pelo esquema de codificação de cabeçalho MIME.

Parâmetros

string

A string a ser codificada. Sua codificação deve ser a mesma que mb_internal_encoding().

charset

charset especifica o nome do conjunto de caracteres no qual string está representada. O valor padrão é determinado pela configuração NLS atual (mbstring.language).

transfer_encoding

transfer_encoding especifica o esquema de codificação MIME. Deve ser ou "B" (Base64) ou "Q" (Quoted-Printable). Retrocede para "B" se não fornecido.

newline

newline especifica o marcador de EOL (end-of-line) com o qual mb_encode_mimeheader() realiza a quebra de linha (um termo » RFC, o ato de quebrar uma linha mais longa que um certo comprimento em várias linhas. O comprimento é atualmente codificado como 74 caracteres). Retrocede para "\r\n" (CRLF) se não fornecido.

indent

Recuo da primeira linha (número de caracteres no cabeçalho antes de string).

Valor Retornado

Uma versão convertida da string representada em ASCII.

Registro de Alterações

Versão Descrição
8.0.0 charset e transfer_encoding agora são anuláveis.

Exemplos

Exemplo #1 Exemplo de mb_encode_mimeheader()

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

O exemplo acima produzirá:

"=?UTF-7?Q?+WSqQzg-?=" <kru@gtinn.mon>

Notas

Nota:

Esta função não é projetada para quebrar linhas em pontos de quebra de contexto de nível superior (limites de palavra, etc.). Esse comportamento pode poluir a string original com espaços inesperados.

Veja Também

add a note

User Contributed Notes 10 notes

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7
stormflyCUT at hyh dot pl
18 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').
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1
nigrez at nius dot waw dot pl
18 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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2
gullevek at gullevek dot org
20 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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2
Anonymous
15 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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1
tokul at users dot sourceforge dot net
16 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
gullevek at gullevek dot org
18 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;
}

?>
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0
paravoid
18 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
chappy at citromail dot hu
18 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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-1
iwakura at junx dot org
18 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
-3
mortoray at ecircle-ag dot com
19 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
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