解码mime邮件的代码

function decode_mime_string ($string) {
$pos = strpos($string, @#=?@#);
if (!is_int($pos)) {
return $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(@#_@#, @#%20@#, $encoded_text);
$encoded_text = str_replace(@#=@#, @#%@#, $encoded_text);
$decoded = urldecode($encoded_text);

if (strtolower($charset) == @#windows-1251@#) {
$decoded = convert_cyr_string($decoded, @#w@#, @#k@#);
}
break;

case @#B@#:
case @#b@#:
$decoded = urldecode(base64_decode($encoded_text));

if (strtolower($charset) == @#windows-1251@#) {
$decoded = convert_cyr_string($decoded, @#w@#, @#k@#);
}
break;

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

return $preceding . $decoded . decode_mime_string($rest);
} // decode_mime_string()

原文转自：http://www.ltesting.net