Send File

// This is pulled from Kohana. You should be able to extract the basic concept of it and implement it in CodeIgniter

	public function send_file($filename, $download = NULL, array $options = NULL)
	{
		if ( ! empty($options['mime_type']))
		{
			// The mime-type has been manually set
			$mime = $options['mime_type'];
		}
 
		if ($filename === TRUE)
		{
			if (empty($download))
			{
				throw new Kohana_Exception('Download name must be provided for streaming files');
			}
 
			if ( ! isset($mime))
			{
				// Guess the mime using the file extension
				$mime = File::mime_by_ext(strtolower(pathinfo($download, PATHINFO_EXTENSION)));
			}
 
			// Get the content size
			$size = strlen($this->response);
 
			// Create a temporary file to hold the current response
			$file = tmpfile();
 
			// Write the current response into the file
			fwrite($file, $this->response);
 
			// Prepare the file for reading
			fseek($file, 0);
		}
		else
		{
			// Get the complete file path
			$filename = realpath($filename);
 
			if (empty($download))
			{
				// Use the file name as the download file name
				$download = pathinfo($filename, PATHINFO_BASENAME);
			}
 
			// Get the file size
			$size = filesize($filename);
 
			if ( ! isset($mime))
			{
				// Get the mime type
				$mime = File::mime($filename);
			}
 
			// Open the file for reading
			$file = fopen($filename, 'rb');
		}
 
		// Inline or download?
		$disposition = empty($options['inline']) ? 'attachment' : 'inline';
 
		// Set the headers for a download
		$this->headers['Content-Disposition'] = $disposition.'; filename="'.$download.'"';
		$this->headers['Content-Type']        = $mime;
		$this->headers['Content-Length']      = $size;
 
		if ( ! empty($options['resumable']))
		{
			// @todo: ranged download processing
		}
 
		// Send all headers now
		$this->send_headers();
 
		while (ob_get_level())
		{
			// Flush all output buffers
			ob_end_flush();
		}
 
		// Manually stop execution
		ignore_user_abort(TRUE);
 
		// Keep the script running forever
		set_time_limit(0);
 
		// Send data in 16kb blocks
		$block = 1024 * 16;
 
		while ( ! feof($file))
		{
			if (connection_aborted())
				break;
 
			// Output a block of the file
			echo fread($file, $block);
 
			// Send the data now
			flush();
		}
 
		// Close the file
		fclose($file);
 
		// Stop execution
		exit;
	}