download.php

This is the script which used on 10minutemail.com for temporary email.

        if (!isset($handle)) {
            $this->handle = null;
            $this->size = 0;
            return true;
        }
        
        if (is_resource($handle)) {
            $this->handle = $handle;
            $filestats    = fstat($handle);
            $this->size   = $filestats['size'];
            return true;
        }

        return PEAR::raiseError(
            "Handle '$handle' is no valid resource.",
            HTTP_DOWNLOAD_E_INVALID_RESOURCE
        );
    }
    
    /**
     * Whether to gzip the download
     *
     * Returns a PEAR_Error (HTTP_DOWNLOAD_E_NO_EXT_ZLIB)
     * if ext/zlib is not available/loadable.
     * 
     * @access  public
     * @return  mixed   Returns true on success or PEAR_Error on failure.
     * @param   bool    $gzip   whether to gzip the download
     */
    function setGzip($gzip = false)
    {
        if ($gzip && !PEAR::loadExtension('zlib')){
            return PEAR::raiseError(
                'GZIP compression (ext/zlib) not available.',
                HTTP_DOWNLOAD_E_NO_EXT_ZLIB
            );
        }
        $this->gzip = (bool) $gzip;
        return true;
    }

    /**
     * Whether to allow caching
     * 
     * If set to true (default) we'll send some headers that are commonly
     * used for caching purposes like ETag, Cache-Control and Last-Modified.
     * 
     * If caching is disabled, we'll send the download no matter if it
     * would actually be cached at the client side.
     *
     * @access  public
     * @return  void
     * @param   bool    $cache  whether to allow caching
     */
    function setCache($cache = true)
    {
        $this->cache = (bool) $cache;
    }
    
    /**
     * Whether to allow proxies to cache
     * 
     * If set to 'private' proxies shouldn't cache the response.
     * This setting defaults to 'public' and affects only cached responses.
     * 
     * @access  public
     * @return  bool
     * @param   string  $cache  private or public
     * @param   int     $maxage maximum age of the client cache entry
     */
    function setCacheControl($cache = 'public', $maxage = 0)
    {
        switch ($cache = strToLower($cache))
        {
            case 'private':
            case 'public':
                $this->headers['Cache-Control'] = 
                    $cache .', must-revalidate, max-age='. $maxage;
                return true;
            break;
        }
        return false;
    }
    
    /**
     * Set ETag
     * 
     * Sets a user-defined ETag for cache-validation.  The ETag is usually
     * generated by HTTP_Download through its payload information.
     * 
     * @access  public
     * @return  void
     * @param   string  $etag Entity tag used for strong cache validation.
     */
    function setETag($etag = null)
    {
        $this->etag = (string) $etag;
    }
    
    /**
     * Set Size of Buffer
     * 
     * The amount of bytes specified as buffer size is the maximum amount
     * of data read at once from resources or files.  The default size is 2M
     * (2097152 bytes).  Be aware that if you enable gzip compression and
     * you set a very low buffer size that the actual file size may grow
     * due to added gzip headers for each sent chunk of the specified size.
     * 
     * Returns PEAR_Error (HTTP_DOWNLOAD_E_INVALID_PARAM) if $size is not
     * greater than 0 bytes.
     * 
     * @access  public
     * @return  mixed   Returns true on success or PEAR_Error on failure.
     * @param   int     $bytes Amount of bytes to use as buffer.
     */
    function setBufferSize($bytes = 2097152)
    {
        if (0 >= (int) $bytes) {
            return PEAR::raiseError(
                'Buffer size must be greater than 0 bytes ('. $bytes .' given)',
                HTTP_DOWNLOAD_E_INVALID_PARAM);
        }
        $this->bufferSize = (int) $bytes;
        return true;
    }
    
    /**
     * Set Throttle Delay
     * 
     * Set the amount of seconds to sleep after each chunck that has been
     * sent.  One can implement some sort of throttle through adjusting the
     * buffer size and the throttle delay.  With the following settings
     * HTTP_Download will sleep a second after each 25 K of data sent.
     * 
     * <code>
     *  Array(
     *      'throttledelay' => 1,
     *      'buffersize'    => 1024 * 25,
     *  )
     * </code>
     * 
     * Just be aware that if gzipp'ing is enabled, decreasing the chunk size 
     * too much leads to proportionally increased network traffic due to added
     * gzip header and bottom bytes around each chunk.
     * 
     * @access  public
     * @return  void
     * @param   float   $seconds    Amount of seconds to sleep after each 
     *                              chunk that has been sent.
     */
    function setThrottleDelay($seconds = 0)
    {
        $this->throttleDelay = abs($seconds) * 1000;
    }
    
    /**
     * Set "Last-Modified"
     *
     * This is usually determined by filemtime() in HTTP_Download::setFile()
     * If you set raw data for download with HTTP_Download::setData() and you
     * want do send an appropiate "Last-Modified" header, you should call this
     * method.
     * 
     * @access  public
     * @return  void
     * @param   int     unix timestamp
     */
    function setLastModified($last_modified)
    {
        $this->lastModified = $this->headers['Last-Modified'] = (int) $last_modified;
    }
    
    /**
     * Set Content-Disposition header
     * 
     * @see HTTP_Download::HTTP_Download
     *
     * @access  public
     * @return  void
     * @param   string  $disposition    whether to send the download
     *                                  inline or as attachment
     * @param   string  $file_name      the filename to display in
     *                                  the browser's download window
     * 
     * <b>Example:</b>
     * <code>
     * $HTTP_Download->setContentDisposition(
     *   HTTP_DOWNLOAD_ATTACHMENT,
     *   'download.tgz'
     * );
     * </code>
     */
    function setContentDisposition( $disposition    = HTTP_DOWNLOAD_ATTACHMENT, 
                                    $file_name      = null)
    {
        $cd = $disposition;
        if (isset($file_name)) {
            $cd .= '; filename="' . $file_name . '"';
        } elseif ($this->file) {
            $cd .= '; filename="' . basename($this->file) . '"';
        }
        $this->headers['Content-Disposition'] = $cd;
    }
    
    /**
     * Set content type of the download
     *
     * Default content type of the download will be 'application/x-octetstream'.
     * Returns PEAR_Error (HTTP_DOWNLOAD_E_INVALID_CONTENT_TYPE) if 
     * $content_type doesn't seem to be valid.
     * 
     * @access  public
     * @return  mixed   Returns true on success or PEAR_Error on failure.
     * @param   string  $content_type   content type of file for download
     */
    function setContentType($content_type = 'application/x-octetstream')
    {
        if (!preg_match('/^[a-z]+\w*\/[a-z]+[\w.;= -]*$/', $content_type)) {
            return PEAR::raiseError(
                "Invalid content type '$content_type' supplied.",
                HTTP_DOWNLOAD_E_INVALID_CONTENT_TYPE
            );
        }
        $this->headers['Content-Type'] = $content_type;
        return true;
    }
    
    /**
     * Guess content type of file
     * 
     * First we try to use PEAR::MIME_Type, if installed, to detect the content 
     * type, else we check if ext/mime_magic is loaded and properly configured.
     *
     * Returns PEAR_Error if:
     *      o if PEAR::MIME_Type failed to detect a proper content type
     *        (HTTP_DOWNLOAD_E_INVALID_CONTENT_TYPE)
     *      o ext/magic.mime is not installed, or not properly configured
     *        (HTTP_DOWNLOAD_E_NO_EXT_MMAGIC)
     *      o mime_content_type() couldn't guess content type or returned
     *        a content type considered to be bogus by setContentType()
     *        (HTTP_DOWNLOAD_E_INVALID_CONTENT_TYPE)
     * 
     * @access  public
     * @return  mixed   Returns true on success or PEAR_Error on failure.
     */
    function guessContentType()
    {
        if (class_exists('MIME_Type') || @include_once 'MIME/Type.php') {
            if (PEAR::isError($mime_type = MIME_Type::autoDetect($this->file))) {
                return PEAR::raiseError($mime_type->getMessage(),
                    HTTP_DOWNLOAD_E_INVALID_CONTENT_TYPE);
            }
            return $this->setContentType($mime_type);
        }
        if (!function_exists('mime_content_type')) {
            return PEAR::raiseError(
                'This feature requires ext/mime_magic!',
                HTTP_DOWNLOAD_E_NO_EXT_MMAGIC
            );
        }
        if (!is_file(ini_get('mime_magic.magicfile'))) {
            return PEAR::raiseError(
                'ext/mime_magic is loaded but not properly configured!',
                HTTP_DOWNLOAD_E_NO_EXT_MMAGIC
            );
        }
        if (!$content_type = @mime_content_type($this->file)) {
            return PEAR::raiseError(
                'Couldn\'t guess content type with mime_content_type().',
                HTTP_DOWNLOAD_E_INVALID_CONTENT_TYPE
            );
        }
        return $this->setContentType($content_type);
    }

    /**
     * Send
     *
     * Returns PEAR_Error if:
     *   o HTTP headers were already sent (HTTP_DOWNLOAD_E_HEADERS_SENT)
     *   o HTTP Range was invalid (HTTP_DOWNLOAD_E_INVALID_REQUEST)
     * 
     * @access  public
     * @return  mixed   Returns true on success or PEAR_Error on failure.
     * @param   bool    $autoSetContentDisposition Whether to set the
     *                  Content-Disposition header if it isn't already.
     */
    function send($autoSetContentDisposition = true)
    {
        if (headers_sent()) {
            return PEAR::raiseError(
                'Headers already sent.',
                HTTP_DOWNLOAD_E_HEADERS_SENT
            );
        }
        
        if (!ini_get('safe_mode')) {
            @set_time_limit(0);
        }
        
        if ($autoSetContentDisposition && 
            !isset($this->headers['Content-Disposition'])) {
            $this->setContentDisposition();
        }
        
        if ($this->cache) {
            $this->headers['ETag'] = $this->generateETag();
            if ($this->isCached()) {
                $this->HTTP->sendStatusCode(304);
                $this->sendHeaders();
                return true;
            }
        } else {
            unset($this->headers['Last-Modified']);
        }
        
        while (@ob_end_clean());
        
        if ($this->gzip) {
            @ob_start('ob_gzhandler');
        } else {
            ob_start();
        }
        
        if ($this->isRangeRequest()) {
            $this->HTTP->sendStatusCode(206);
            $chunks = $this->getChunks();
        } else {
            $this->HTTP->sendStatusCode(200);
            $chunks = array(array(0, $this->size));
            if (!$this->gzip && count(ob_list_handlers()) < 2) {
                $this->headers['Content-Length'] = $this->size;
            }
        }

        if (PEAR::isError($e = $this->sendChunks($chunks))) {
            ob_end_clean();
            $this->HTTP->sendStatusCode(416);
            return $e;
        }
        
        ob_end_flush();
        flush();
        return true;