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