©
Ce document utilise Manuel du site Web PHP chinois Libérer
(PHP 4 >= 4.0.6, PHP 5)
mb_encode_mimeheader — 为 MIME 头编码字符串
$str
[, string $charset
= mb_internal_encoding()
[, string $transfer_encoding
= "B"
[, string $linefeed
= "\r\n"
[, int $indent
= 0
]]]] )
按 MIME 头编码方案将指定的 字符串 str
进行编码。
str
要编码的 string 。
charset
charset
指定了 str
的字符集名。
其默认值由当前的 NLS 设置(mbstring.language)来确定。
mb_internal_encoding() 应当设置为同样的编码。
transfer_encoding
transfer_encoding
指定了 MIME 的编码方案。
它可以是 "B"(Base64)也可以是 "Q"(Quoted-Printable)。
如果未设置,将回退为 "B"。
linefeed
linefeed
指定了 EOL(行尾)标记,使 mb_encode_mimeheader() 执行了一个换行(» RFC 文档中规定,超过长度的一行将换成多行,当前该长度硬式编码为 74 个字符)。
如果没有设定,则回退为 "\r\n" (CRLF)。
indent
首行缩进(header 里 str
前的字符数目)。
转换后的 字符串 版本以 ASCII 形式表达。
Example #1 mb_encode_mimeheader() 例子
<?php
$name = "" ; // kanji
$mbox = "kru" ;
$doma = "gtinn.mon" ;
$addr = mb_encode_mimeheader ( $name , "UTF-7" , "Q" ) . " <" . $mbox . "@" . $doma . ">" ;
echo $addr ;
?>
Note:
这个函数没有设计成据更高级上下文的中断点来换行(单词边界等)。 这个特性将导致意外的空格可能会让原始字符串看上去很乱。
[#1] Anonymous [2009-04-11 18:19:35]
I could not find a PHP function to MIME encode the name for a n email address.
Input = "Karl M??ller<kmueller@gmx.de>"
Output = "Karl%20M%FCller<kmueller@gmx.de>"
I wrote it on my own:
<?php
// required to encode names in email addresses
// replace " " with "%20"
// replace "??" with "%FC"
// replace "%" with "%25" etc....
// Use "%" as Delimiter for MIME
// Use "=" as Delimiter for Quoted Printable
// Input string must be UTF8 encoded
public static function EncodeMime($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;
}
?>
[#2] tokul at users dot sourceforge dot net [2008-03-30 04:26:36]
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 $charset
[#3] chappy at citromail dot hu [2006-06-05 04:33:59]
I found a bad function.
<?php
function encodeHeader($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 $input;
}
?>
[#4] stormflyCUT at hyh dot pl [2006-05-05 04:41:46]
Some solution for using national chars and have problem with UTF-8 for example in mail subject. Before you use mb_encode_mimeheader with UTF-8 set mb_internal_encoding('UTF-8').
[#5] paravoid [2006-01-01 17:58:23]
If mb_ version doesn't work for you in MIME-B mode:
function encode_mimeheader($string, $charset=null, $linefeed="\r\n") {
if (!$charset)
$charset = mb_internal_encoding();
$start = "=?$charset?B?";
$end = "?=";
$encoded = '';
$length = 75 - strlen($start) - strlen($end);
$ratio = mb_strlen($string, $charset) / strlen($string);
$magic = $avglength = floor(3 * $length * $ratio / 4);
for ($i=0; $i <= mb_strlen($string, $charset); $i+=$magic) {
$magic = $avglength;
$offset = 0;
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;
}
$encoded = substr($encoded, 1, -strlen($linefeed));
return $encoded;
}
[#6] nigrez at nius dot waw dot pl [2005-12-13 15:42:26]
True, function is broken (PHP5.1, encoding from UTF-8 with pl_PL charset). Below is about 15% faster version of proposed _mb_mime_encode. Also it has header more like othe mb_* functions and doesn't trigger any errors/warnings/notices.
<?php
function mb_mime_header($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 $encoded;
}
?>
[#7] gullevek at gullevek dot org [2005-11-06 17:29:18]
My first post was around 2003, and still the mb_mime_header is broken. It is *NOT* usable with longer subjects, and mostly unusable with anything else than japanese.
iwakura at junx dot org is also not working for me, it produces also some gargabe.
I updated my old function (the one I posted 2003) and I tested it with overlong subjects in UTF-8, ISO-2022-JP (japanese), GB2312 (simplified chinese) and EUC-KR (korean) and I got readable results in thunderbird, mail.app, outlook, etc.
<?php
function _mb_mime_encode($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 $string;
}
?>
[#8] chappy at citromail dot hu [2005-10-28 23:14:36]
[#9] iwakura at junx dot org [2005-09-15 23:35:15]
i think mb_encode_mimeheader still have bug. here is sample code:
function mb_encode_mimeheader2($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
[#10] mortoray at ecircle-ag dot com [2005-03-15 01:19:59]
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
[#11] gullevek at gullevek dot org [2003-07-30 00:02:10]
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
[#12] masataka [2003-04-12 07:46:20]
second parameter 'charset' is character encoding name, but default must be UTF-8 on PHP4.3.1.