使用php的编码功能-mime.inc

<?php
// $Horde: horde/lib/MIME.php,v 1.63 2001/08/08 21:00:27 chuck Exp $

$mime_types =
array(
TYPETEXT => 'text', 'text' => TYPETEXT,
TYPEMULTIPART => 'multipart', 'multipart' => TYPEMULTIPART,
TYPEMESSAGE => 'message', 'message' => TYPEMESSAGE,
TYPEAPPLICATION => 'application', 'application' => TYPEAPPLICATION,
TYPEAUDIO => 'audio', 'audio' => TYPEAUDIO,
TYPEIMAGE => 'image', 'image' => TYPEIMAGE,
TYPEVIDEO => 'video', 'video' => TYPEVIDEO,
TYPEOTHER => 'unknown', 'unknown' => TYPEOTHER
);

$mime_encodings =
array(
ENC7BIT => '7bit', '7bit' => ENC7BIT,
ENC8BIT => '8bit', '8bit' => ENC8BIT,
ENCBINARY => 'binary', 'binary' => ENCBINARY,
ENCBASE64 => 'base64', 'base64' => ENCBASE64,
ENCQUOTEDPRINTABLE => 'quoted-printable', 'quoted-printable' => ENCQUOTEDPRINTABLE,
ENCOTHER => 'unknown', 'unknown' => ENCOTHER
);


/**
* The MIME:: class provides methods for dealing with MIME standards.
*
* @author Chuck Hagenbuch <chuck@horde.org>
* @version $Revision: 1.64 $
* @since Horde 1.3
* @package horde.mime
*/
class MIME {

/**
* Determine if a string contains 8-bit characters.
* @aclearcase/" target="_blank" >ccess private
*
* @param string $string The string to check.
* @return boolean true if it does, false if it doesn't.
*/
function is8bit($string)
{
if (is_string($string)) {
for ($i = 0; $i < strlen($string); $i ) {
if (ord($string[$i]) >> 7)
return true;
}
return false;
}
return false;
}

/**
* Encode a string containing non-ascii characters according to RFC 2047.
*
* @param string $text The text to encode.
* @param string $charset (optional) The character set of the text.
* @param boolean $outer Is this the final iteration?
*
* @return string The text, encoded only if it contains non-ascii characters.
*/
function encode($text, $charset = null, $outer = true)
{
if (MIME::is8bit($text)) {
if (((strlen($text) * 3) strlen($charset) 7) > 76) {
$text = MIME::encode(substr($text, 0, (23 - strlen($charset))), $charset) . MIME::encode(substr($text, (23 - strlen($charset))), $charset, false);
} else {
$text = "=?$charset?B?" . strtr(trim(base64_encode($text)), ' ', '_') . "?=\n\t";
}
}

// if this is the final iteration, take off any trailing
// newline/tab chars.
if ($outer && (substr($text, -2) == "\n\t"))
$text = substr($text, 0, -2);

return $text;
}

/**
* Encode a string containing email addresses according to RFC 2047.
*
* This differs from MIME::encode() because it keeps email
* addresses legal, only encoding the personal information.
*
* @param string $text The email addresses to encode.
* @param string $charset (optional) The character set of the text.
* @param string $defserver (optional) The default domain to append to mailboxes.
*
* @return string The text, encoded only if it contains non-ascii characters.
*/
function encodeAddress($text, $charset = null, $defserver = null)
{
include_once 'Mail/RFC822.php';

$addr_arr = Mail_RFC822::parseAddressList($text, $defserver, false, false);
$text = '';
if (is_array($addr_arr)) {
foreach ($addr_arr as $addr) {
if (empty($addr->personal)) {
$personal = '';
} else {
if ((substr($addr->personal, 0, 1) == '"') &&
(substr($addr->personal, -1) == '"')) {
$addr->personal = substr($addr->personal, 1, -1);
}
$personal = MIME::encode($addr->personal, $charset);
}
if (strlen($text) != 0) $text .= ', ';
// FIXME: dependency on imap module
$text .= MIME::trimEmailAddress(imap_rfc822_write_address($addr->mailbox, $addr->host, $personal));
}
}
return $text;
}

/**
* Decode an RFC 2047-encoded string.
*
* @param string $string The text to decode.
* @return string The decoded text, or the original string if it was not encoded.
*/
function decode($string)
{
$pos = strpos($string, '=?');
if ($pos === false) {
return $string;
}

// take out any spaces between multiple encoded words
$string = preg_replace('|\?=\s=\?|', '?==?', $string);

$preceding = substr($string, 0, $pos); // save any preceding text

$search = substr($string, $pos 2, 75); // the mime header spec says this is the longest a single encoded word can be
$d1 = strpos($search, '?');
if (!is_int($d1)) {
return $string;
}

$charset = substr($string, $pos 2, $d1);
$search = substr($search, $d1 1);

$d2 = strpos($search, '?');
if (!is_int($d2)) {
return $string;
}

$encoding = substr($search, 0, $d2);
$search = substr($search, $d2 1);

$end = strpos($search, '?=');
if (!is_int($end)) {
return $string;
}

$encoded_text = substr($search, 0, $end);
$rest = substr($string, (strlen($preceding . $charset . $encoding . $encoded_text) 6));

switch ($encoding) {
case 'Q':
case 'q':
$encoded_text = str_replace('_', ' ', $encoded_text);
$encoded_text = str_replace('=', '%', $encoded_text);
$decoded = urldecode($encoded_text);

/* Convert Cyrillic character sets. */
if (stristr($GLOBALS['registry']->getCharset(), 'windows-1251')) {
if (stristr($charset, 'koi8-r')) {
$decoded = convert_cyr_string($decoded, 'k', 'w');
}
}
if (stristr($GLOBALS['registry']->getCharset(), 'koi8-r')) {
if (stristr($charset, 'windows-1251')) {
$decoded = convert_cyr_string($decoded, 'w', 'k');
}
}

break;

case 'B':
case 'b':
$decoded = urldecode(base64_decode($encoded_text));
if (stristr($GLOBALS['registry']->getCharset(), 'windows-1251')) {
if (stristr($charset, 'koi8-r')) {
$decoded = convert_cyr_string($decoded, 'k', 'w');
}
}
if (stristr($GLOBALS['registry']->getCharset(), 'koi8-r')) {
if (stristr($charset, 'windows-1251')) {
$decoded = convert_cyr_string($decoded, 'w', 'k');
}
}
break;

default:
$decoded = '=?' . $charset . '?' . $encoding . '?' . $encoded_text . '?=';
break;
}

return $preceding . $decoded . MIME::decode($rest);
}

/**
* If an email address has no personal information, get rid of any
* angle brackets (<>) around it.
*
* @param string $address The address to trim.
* @return string The trimmed address.
*/
function trimEmailAddress($address)
{
$address = trim($address);
if ((substr($address, 0, 1) == '<') && (substr($address, -1) == '>')) {
$address = substr($address, 1, -1);
}
return $address;
}

}
?>

原文转自：http://www.ltesting.net