quoted_printable_decode

(PHP 4, PHP 5, PHP 7, PHP 8)

quoted_printable_decode — 将 quoted-printable 字符串转换为 8-bit 字符串

说明

quoted_printable_decode(string $str): string

该函数返回 quoted-printable 解码之后的 8-bit 字符串 (参考 » RFC2045 的6.7章节，而不是 » RFC2821 的4.5.2章节，so additional periods are not stripped from the beginning of line)

该函数与 imap_qprint() 函数十分相似，但是该函数不需要依赖 IMAP 模块。

参数

str

输入的字符串。

返回值

返回的 8-bit 二进制字符串。

参见

add a noteadd a note

User Contributed Notes 21 notes

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3
legolas558 at users dot sausafe dot net
15 years ago
As soletan at toxa dot de reported, that function is very bad and does not provide valid enquoted printable strings. While using it I saw spam agents marking the emails as QP_EXCESS and sometimes the email client did not recognize the header at all; I really lost time :(. This is the new version (we use it in the Drake CMS core) that works seamlessly:

<?php

//L: note $encoding that is uppercase
//L: also your PHP installation must have ctype_alpha, otherwise write it yourself
function quoted_printable_encode($string, $encoding='UTF-8') {
// use this function with headers, not with the email body as it misses word wrapping
       $len = strlen($string);
       $result = '';
       $enc = false;
       for($i=0;$i<$len;++$i) {
        $c = $string[$i];
        if (ctype_alpha($c))
            $result.=$c;
        else if ($c==' ') {
            $result.='_';
            $enc = true;
        } else {
            $result.=sprintf("=%02X", ord($c));
            $enc = true;
        }
       }
       //L: so spam agents won't mark your email with QP_EXCESS
       if (!$enc) return $string;
       return '=?'.$encoding.'?q?'.$result.'?=';
}

I hope it helps ;)

?>
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2
Karora
13 years ago
Taking a bunch of the earlier comments together, you can synthesize a nice short and reasonably efficient quoted_printable_encode function like this:

Note that I put this in my standard library file, so I wrap it in a !function_exists in order that if there is a pre-existing PHP one it will just work and this will evaluate to a noop.

<?php
if ( !function_exists("quoted_printable_encode") ) {
  /**
  * Process a string to fit the requirements of RFC2045 section 6.7.  Note that
  * this works, but replaces more characters than the minimum set. For readability
  * the spaces aren't encoded as =20 though.
  */
  function quoted_printable_encode($string) {
    return preg_replace('/[^\r\n]{73}[^=\r\n]{2}/', "$0=\r\n", str_replace("%","=",str_replace("%20"," ",rawurlencode($string))));
  }
}
?>

Regards,
Andrew McMillan.
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2
yual at inbox dot ru
8 years ago
I use a hack for this bug:

$str = str_replace("=\r\n", '', quoted_printable_encode($str));
if (strlen($str) > 73) {$str = substr($str,0,74)."=\n".substr($str,74);}
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2
roelof
14 years ago
I modified the below version of legolas558 at users dot sausafe dot net and added a wrapping option.

<?php
/**
*    Codeer een String naar zogenaamde 'quoted printable'. Dit type van coderen wordt
*    gebruikt om de content van 8 bit e-mail berichten als 7 bits te versturen.
*
*    @access public
*    @param string    $str    De String die we coderen
*    @param bool      $wrap   Voeg linebreaks toe na 74 tekens?
*    @return string
*/

function quoted_printable_encode($str, $wrap=true)
{
    $return = '';
    $iL = strlen($str);
    for($i=0; $i<$iL; $i++)
    {
        $char = $str[$i];
        if(ctype_print($char) && !ctype_punct($char)) $return .= $char;
        else $return .= sprintf('=%02X', ord($char));
    }
    return ($wrap === true)
        ? wordwrap($return, 74, " =\n")
        : $return;
}

?>
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2
legolas558
15 years ago
Please note that in the below encode function there is a bug!

<?php
if (($c==0x3d) || ($c>=0x80) || ($c<0x20))
?>

$c should be checked against less or equal to encode spaces!

so the correct code is

<?php
if (($c==0x3d) || ($c>=0x80) || ($c<=0x20))
?>

Fix the code or post this note, please
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2
madmax at express dot ru
21 years ago
Some  browser (netscape, for example)
send 8-bit quoted printable text like this:
=C5=DD=A3=D2=C1= =DA

"= =" means continuos word.
php function not detect this situations and translate in string like:
abcde=f
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1
Thomas Pequet / Memotoo.com
15 years ago
If you want a function to do the reverse of "quoted_printable_decode()", follow the link you will find the "quoted_printable_encode()" function:
http://www.memotoo.com/softs/public/PHP/quoted printable_encode.inc.php

Compatible "ENCODING=QUOTED-PRINTABLE"
Example:
quoted_printable_encode(ut8_encode("c'est quand l'été ?"))
-> "c'est quand l'=C3=A9t=C3=A9 ?"
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1
ludwig at gramberg-webdesign dot de
14 years ago
my approach for quoted printable encode using the stream converting abilities

<?php
/**
* @param string $str
* @return string
* */
function quoted_printable_encode($str) {
    $fp = fopen('php://temp', 'w+');
    stream_filter_append($fp, 'convert.quoted-printable-encode');
    fwrite($fp, $str);   
    fseek($fp, 0);
    $result = '';
    while(!feof($fp))
        $result .= fread($fp, 1024);
    fclose($fp);
    return $result;
}
?>
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1
soletan at toxa dot de
15 years ago
Be warned! The method below for encoding text does not work as requested by RFC1521!

Consider a line consisting of 75 'A' and a single é (or similar non-ASCII character) ... the method below would encode and return a line of 78 octets, breaking with RFC 1521, 5.1 Rule #5: "The Quoted-Printable encoding REQUIRES that encoded lines be no more than 76 characters long."

Good QP-encoding takes a bit more than this.
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1
steffen dot weber at computerbase dot de
16 years ago
As the two digit hexadecimal representation SHOULD be in uppercase you want to use "=%02X" (uppercase X) instead of "=%02x" as the first argument to sprintf().
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1
pob at medienrecht dot NOSPAM dot org
20 years ago
If you do not have access to imap_* and do not want to use

备份地址：http://www.lvesu.com/blog/php/function.quoted-printable-decode.php