一个邮件解码类

/**这个是改自pear中的解码类，增加了多种解码方式，修正了源码的系列bug.将解出的邮件分正文和附件存储，提高了解码效率。
* Mime decode class
*
* this class used at undecode Mime Files
* useage:
*
* $message=GetMessage($filename,$read_type,$read_size);
* $structure=RdMail($message);
* $from=$structure->headers['from'];
* $to=$structure->headers['to'];
*
* @copyright (c) 2004, richard,bjcctv. All rights reserved.
* @author richard,bjcctv
* @date:2004-11-24 last modified at:2005-06-01
* @package MimeDecode
* @version $Id$
*/

class Decode_Mimemail
{

/**
* Mime File
* @var string
*/
var $_input;

/**
* header string
* @var string
*/
var $_header;

/**
* body string
* @var string
*/
var $_body;

/**
* err info
* @var string
*/
var $_error;

/**
* whether include body object
* @var boolean
*/
var $_include_bodies;

/**
* whether include body object
* @var boolean
*/
var $_decode_bodies;

/**
* whether decode headers object
* @var boolean
*/
var $_decode_headers;

/**
* crlf variable
* @var string
*/
var $_crlf;

/**
* body parts
* @var object
*/
var $parts;
var $mid;
var $maildir;

/**
* Constructor.
*
* Sets up the object, initialise the variables, and splits and
* stores the header and body of the input.
*
* @param string The input to decode
* @access public
*/

function Decode_Mimemail($input, $mid, $maildir, $crlf = "\n")
{
$this->_crlf = "\n";
list($header, $body) = $this->splitBodyHeader($input); //拆分信头和信体两块
$this->_input = $input;
$this->_header = $header;
$this->_body = $body;
$this->mid = $mid;
$this->maildir = $maildir;
$this->_decode_bodies = false;
$this->_include_bodies = true;
}

/**
* Begins the decoding process. If called statically
* it will create an object and call the decode() method
* of it.
*
* @param array An array of various parameters that determine
* various things:
* include_bodies - Whether to include the body in the returned
* object.
* decode_bodies - Whether to decode the bodies
* of the parts. (Transfer encoding)
* decode_headers - Whether to decode headers
* input - If called statically, this will be treated
* as the input
* @return object Decoded results
* @access public
*/

function decode($params = null)
{
// Have we been called statically?
// If so, create an object and pass details to that.
if (!isset($this) AND isset($params['input']))
{
if (isset($params['crlf']))
{
$obj = new Decode_Mimemail($params['input'],$params['mid'],$params['maildir'],$params['crlf']);
}
else
{
$obj = new Decode_Mimemail($params['input'],$params['mid'],$params['maildir']);
}
$structure = $obj->decode($params);

// Called statically but no input
}
elseif (!isset($this))
{
return $this->_error="Called statically and no input given";

// Called via an object
}
else
{
$this->_include_bodies = isset($params['include_bodies'])
? $params['include_bodies']
: false;
$this->_decode_bodies = isset($params['decode_bodies'])
? $params['decode_bodies']
: false;
$this->_decode_headers = isset($params['decode_headers'])
? $params['decode_headers']
: false;
if (is_null($this->_header) || is_null($this->_body)
|| is_null($this->mid) || is_null($this->maildir))
{
$structure = false;
}
else
{
$structure = $this->_decode($this->_header, $this->_body, $this->mid, $this->maildir);
}
if($structure === false)
{
$structure = $this->_error;
}
}
return $structure;
}

/**
* Performs the decoding. Decodes the body string passed to it
* If it finds certain content-types it will call itself in a
* recursive fashion
*
* @param string Header section
* @param string Body section
* @param string mid mime filename
* @return object Results of decoding process
* @access private
*/

function _decode($headers, $body, $mid, $maildir, $default_ctype = 'text/plain')
{
$return = new stdClass;
if(!is_null($headers))
{
$headers = $this->parseHeaders($headers);
}
else{
$this->_error="the mime headers is null.";
return $this->_error;
}

foreach ($headers as $value)
{
if (isset($return->headers[$value['name']]) AND !is_array($return->headers[$value['name']]))
{
$return->headers[$value['name']] = array($return->headers[$value['name']]);
$return->headers[$value['name']][] = $value['value'];
}
elseif (isset($return->headers[$value['name']]))
{
$return->headers[$value['name']][] = $value['value'];
}
else
{
$return->headers[$value['name']] = $value['value'];
}
}
reset($headers);
//rewinds array's internal pointer to the first element and returns the value of the first array element.
while (list($key, $value) = each($headers))
{
$headers[$key]['name'] = strtolower($headers[$key]['name']);
switch ($headers[$key]['name'])
{
case 'content-type':
$content_type = $this->parseHeaderValue($headers[$key]['value']);
if (preg_match('/([0-9a-z+.-]+)/([0-9a-z+.-]+)/i', $content_type['value'], $regs))
{
$return->ctype_primary = $regs[1];
$return->ctype_secondary = $regs[2];
}
if (isset($content_type['other']))
{
while (list($p_name, $p_value) = each($content_type['other']))
{
$return->ctype_parameters[$p_name] = $p_value;
}
}
break;

case 'content-disposition':
$content_disposition = $this->parseHeaderValue($headers[$key]['value']);
$return->disposition = $content_disposition['value'];
if (isset($content_disposition['other']))
{
while (list($p_name, $p_value) = each($content_disposition['other']))
{
$return->d_parameters[$p_name] = $p_value;
}
}
break;
case 'content-transfer-encoding':
if(!is_null($this->parseHeaderValue($headers[$key]['value'])))
{
$content_transfer_encoding = $this->parseHeaderValue($headers[$key]['value']);
}
else{
$content_transfer_encoding = "";
}
break;
}
}
if (isset($content_type))
{
$content_type['value'] = strtolower($content_type['value']);
switch ($content_type['value'])
{
case 'text':
case 'text/plain':
if($this->_include_bodies)
{
if($this->_decode_bodies)
{
$return->body = isset($content_transfer_encoding['value'])
?$this->decodeBody($body,$content_transfer_encoding['value'])
: $body;
}
else{
$return->body = $body;
}

if(!isset($content_type['other']['charset']))
{
$content_type['other']['charset']="gb2312";
}
if($content_type['other']['charset'] != "")
{
$orim_str = "----- Original Message -----";
$orim_startpos = strpos($return->body,$orim_str);
if(is_int($orim_startpos))
{
$return->body = $return->body;
}
else{
$return->body = str_replace("body);
$return->body = str_replace(">",">",$return->body);
$return->body = str_replace("\n","
",$return->body);
$return->body = str_replace(" "," ",$return->body);
}
}
}
$return->body = $this->ConverUrltoLink($return->body);
$return->body = str_replace("
","
",$return->body);
$return->body = str_replace(" "," ",$return->body);
if(strtolower($return->ctype_parameters['charset'])=="utf-8")
{
$return->body=iconv("utf-8", "gb2312", $return->body);
}
break;

case 'text/html':
if($this->_include_bodies)
{
if($this->_decode_bodies)
{
$return->body = isset($content_transfer_encoding['value'])
? $this->decodeBody($body,$content_transfer_encoding['value'])
: $body;
}
else{
$return->body = $body;
}
}
$return->body = $this->ConverUrltoLink($return->body);
if(strtolower($return->ctype_parameters['charset'])=="utf-8")
{
$return->body=iconv("utf-8", "gb2312", $return->body);
}
break;
case 'multipart/mixed':
case 'multipart/alternative':
case 'multipart/digest':
case 'multipart/parallel':
case 'multipart/report': // RFC1892
case 'multipart/signed': // PGP
case 'multipart/related':
case 'application/x-pkcs7-mime':
if(!isset($content_type['other']['boundary']))
{
$this->_error = 'No boundary found for '.$content_type['value'].' part';
return false;
}
$default_ctype = (strtolower($content_type['value']) === 'multipart/digest')
? 'message/rfc822'
: 'text/plain';
$parts = $this->boundarySplit($body, $content_type['other']['boundary']);

if(!isset($return->attlist))
{
$return->attlist="";
}
for ($i = 0; $i {
list($part_header, $part_body) = $this->splitBodyHeader($parts[$i]);
if (is_null($part_header) || is_null($part_body))
{
$part = false;
}
else
{
$part = $this->_decode($part_header, $part_body, $mid, $maildir, $default_ctype);
}
if($part === false)
{
$part =$this->_error;
}
if(!is_null($part->ctype_primary) AND !is_null($part->ctype_secondary))
{
$part_content_type=$part->ctype_primary."/".$part->ctype_secondary;
}
else{
$part_content_type="";
}

if(isset($part->body))
{
if(isset($part->headers['content-transfer-encoding']) AND !is_null($part->headers['content-transfer-encoding']))
{
$part->body = $this->decodeBody($part->body,$part->headers['content-transfer-encoding']);
}
else{
$part->body = $part->body;
}
}
/**
* if part exists with filename/name,save to disk.
*/
if(!isset($part->body))
{
$part->body = $this->decodeBody($part_body, "base64");
}

if((($part->ctype_primary."/".$part->ctype_secondary=="message/rfc822") OR ($part->ctype_parameters['name']!="") OR ($part->headers['content-id']!="") OR (isset($part->d_parameters['filename']) AND isset($part->disposition))) AND isset($part->body))
{
$att_savename= $mid.".att".$i; //attachment save name.
$user_cache=$this->maildir;
if(!empty($user_cache) AND !empty($att_savename))
{
$att_file=$user_cache."/".$att_savename;
}
else
{
$att_file="";
$return->parts[] = $part;
break;
}
$att_filename = $part->ctype_parameters['name'];
if($att_filename=="")
{
$att_filename = $part->d_parameters['filename']==""
? $att_filename = "autofile".$i
: $part->d_parameters['filename'];
//if the attachment is the type of rfc/822,and filename is null
//rename to autofile with ".eml"
if(($part->ctype_primary."/".$part->ctype_secondary=="message/rfc822") and $att_filename=="autofile".$i)
{
$att_filename = $att_filename.".eml";
}
}
$this->createAttfiles($att_file,$part->body);
, $attfile_size=filesize($att_file);
$return->attlist.=$att_filename."|".$attfile_size."|".$att_savename."|".$part_content_type."\n";
$logName=$user_cache."/.attlog";
$LogContent = $att_savename."\n";
$this->CreateLog($logName,$LogContent);
$part->body = ""; //released the used memory
}
else
{
if(isset($part->body))
{
$return->body=$part->body;
}
}
$return->parts[] = $part;
}
break;
case 'image/gif':
case 'image/jpeg':
break;
default:
if($this->_include_bodies)
{
if($this->_decode_bodies)
{
$return->body = isset($content_transfer_encoding['value'])
?$this->decodeBody($body,$content_transfer_encoding['value'])
:$body;
}
else{
$return->body = $body;
}
}
break;
} // end switch

}
else {
//process if content-type isn't exist.
$ctype = explode('/', $default_ctype);
$return->ctype_primary = $ctype[0];
$return->ctype_secondary = $ctype[1];
$this->_include_bodies
? $return->body = ($this->_decode_bodies
? $this->decodeBody($body)
: $body)
: null;
if($this->_include_bodies)
{
$orim_str = "----- Original Message -----";
$orim_startpos = strpos($return->body,$orim_str);
if(is_int($orim_startpos))
{
$return->body = $return->body;
}
else{
$return->body = str_replace("\n","
",$return->body);
$return->body = str_replace(" "," ",$return->body);
}
}
$return->body = $this->ConverUrltoLink($return->body);
$return->body = str_replace("
","
",$return->body);
$return->body = str_replace(" "," ",$return->body);
if(strtolower($return->ctype_parameters['charset'])=="utf-8")
{
$return->body=iconv("utf-8", "gb2312", $return->body);
}
} //end else
if(0attlist))
{
$return->attlist = substr($return->attlist,0,(strlen($return->attlist)-1));
}
return $return;
}

/**
* Given a string containing a header and body
* section, this function will split them (at the first blank line) and return them.
*
* @param string Input to split apart
* @return array Contains header and body section
* @access private
*/

function splitBodyHeader($input)
{
$pos = strpos($input, $this->_crlf.$this->_crlf);
if ($pos === false)
{
$this->_error = 'Could not split header and body';
return false;
}

$header = substr($input, 0, $pos);
$body = substr($input, $pos+(2*strlen($this->_crlf)));
return array($header, $body);
}

/**
* Parse headers given in $input and return as assoc array.
*
* @param string Headers to parse
* @return array Contains parsed headers
* @access private
*/

function parseHeaders($input)
{
if ($input !== '')
{
// Unfold the input
$input = preg_replace('/' . $this->_crlf . "(\t| )/", ' ', $input);
$headers = explode($this->_crlf, trim($input));

foreach ($headers as $value)
{
$hdr_name = strtolower(substr($value, 0, $pos = strpos($value, ':')));
$hdr_value = substr($value, $pos+1);
$return[] = array(
'name' => $hdr_name,
'value' => $this->_decode_headers
? $this->decodeHeader($hdr_value)
&nbs