<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP 5.1.6 or newer

 *

 * @package		CodeIgniter

 * @author		ExpressionEngine Dev Team

 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.

 * @license		http://codeigniter.com/user_guide/license.html

 * @link		http://codeigniter.com

 * @since		Version 1.0

 * @filesource

 */



// ------------------------------------------------------------------------



/**

 * File Uploading Class

 *

 * @package		CodeIgniter

 * @subpackage	Libraries

 * @category	Uploads

 * @author		ExpressionEngine Dev Team

 * @link		http://codeigniter.com/user_guide/libraries/file_uploading.html

 */

class CI_Upload {



	public $max_size				= 0;

	public $max_width				= 0;

	public $max_height				= 0;

	public $max_filename			= 0;

	public $allowed_types			= "";

	public $file_temp				= "";

	public $file_name				= "";

	public $orig_name				= "";

	public $file_type				= "";

	public $file_size				= "";

	public $file_ext				= "";

	public $upload_path				= "";

	public $overwrite				= FALSE;

	public $encrypt_name			= FALSE;

	public $is_image				= FALSE;

	public $image_width				= '';

	public $image_height			= '';

	public $image_type				= '';

	public $image_size_str			= '';

	public $error_msg				= array();

	public $mimes					= array();

	public $remove_spaces			= TRUE;

	public $xss_clean				= FALSE;

	public $temp_prefix				= "temp_file_";

	public $client_name				= '';



	protected $_file_name_override	= '';



	/**

	 * Constructor

	 *

	 * @access	public

	 */

	public function __construct($props = array())

	{

		if (count($props) > 0)

		{

			$this->initialize($props);

		}



		log_message('debug', "Upload Class Initialized");

	}



	// --------------------------------------------------------------------



	/**

	 * Initialize preferences

	 *

	 * @param	array

	 * @return	void

	 */

	public function initialize($config = array())

	{

		$defaults = array(

							'max_size'			=> 0,

							'max_width'			=> 0,

							'max_height'		=> 0,

							'max_filename'		=> 0,

							'allowed_types'		=> "",

							'file_temp'			=> "",

							'file_name'			=> "",

							'orig_name'			=> "",

							'file_type'			=> "",

							'file_size'			=> "",

							'file_ext'			=> "",

							'upload_path'		=> "",

							'overwrite'			=> FALSE,

							'encrypt_name'		=> FALSE,

							'is_image'			=> FALSE,

							'image_width'		=> '',

							'image_height'		=> '',

							'image_type'		=> '',

							'image_size_str'	=> '',

							'error_msg'			=> array(),

							'mimes'				=> array(),

							'remove_spaces'		=> TRUE,

							'xss_clean'			=> FALSE,

							'temp_prefix'		=> "temp_file_",

							'client_name'		=> ''

						);





		foreach ($defaults as $key => $val)

		{

			if (isset($config[$key]))

			{

				$method = 'set_'.$key;

				if (method_exists($this, $method))

				{

					$this->$method($config[$key]);

				}

				else

				{

					$this->$key = $config[$key];

				}

			}

			else

			{

				$this->$key = $val;

			}

		}



		// if a file_name was provided in the config, use it instead of the user input

		// supplied file name for all uploads until initialized again

		$this->_file_name_override = $this->file_name;

	}



	// --------------------------------------------------------------------



	/**

	 * Perform the file upload

	 *

	 * @return	bool

	 */

	public function do_upload($field = 'userfile')

	{



	// Is $_FILES[$field] set? If not, no reason to continue.

		if ( ! isset($_FILES[$field]))

		{

			$this->set_error('upload_no_file_selected');

			return FALSE;

		}



		// Is the upload path valid?

		if ( ! $this->validate_upload_path())

		{

			// errors will already be set by validate_upload_path() so just return FALSE

			return FALSE;

		}



		// Was the file able to be uploaded? If not, determine the reason why.

		if ( ! is_uploaded_file($_FILES[$field]['tmp_name']))

		{

			$error = ( ! isset($_FILES[$field]['error'])) ? 4 : $_FILES[$field]['error'];



			switch($error)

			{

				case 1:	// UPLOAD_ERR_INI_SIZE

					$this->set_error('upload_file_exceeds_limit');

					break;

				case 2: // UPLOAD_ERR_FORM_SIZE

					$this->set_error('upload_file_exceeds_form_limit');

					break;

				case 3: // UPLOAD_ERR_PARTIAL

					$this->set_error('upload_file_partial');

					break;

				case 4: // UPLOAD_ERR_NO_FILE

					$this->set_error('upload_no_file_selected');

					break;

				case 6: // UPLOAD_ERR_NO_TMP_DIR

					$this->set_error('upload_no_temp_directory');

					break;

				case 7: // UPLOAD_ERR_CANT_WRITE

					$this->set_error('upload_unable_to_write_file');

					break;

				case 8: // UPLOAD_ERR_EXTENSION

					$this->set_error('upload_stopped_by_extension');

					break;

				default :   $this->set_error('upload_no_file_selected');

					break;

			}



			return FALSE;

		}





		// Set the uploaded data as class variables

		$this->file_temp = $_FILES[$field]['tmp_name'];

		$this->file_size = $_FILES[$field]['size'];

		$this->_file_mime_type($_FILES[$field]);

		$this->file_type = preg_replace("/^(.+?);.*$/", "\\1", $this->file_type);

		$this->file_type = strtolower(trim(stripslashes($this->file_type), '"'));

		$this->file_name = $this->_prep_filename($_FILES[$field]['name']);

		$this->file_ext	 = $this->get_extension($this->file_name);

		$this->client_name = $this->file_name;



		// Is the file type allowed to be uploaded?

		if ( ! $this->is_allowed_filetype())

		{

			$this->set_error('upload_invalid_filetype');

			return FALSE;

		}



		// if we're overriding, let's now make sure the new name and type is allowed

		if ($this->_file_name_override != '')

		{

			$this->file_name = $this->_prep_filename($this->_file_name_override);



			// If no extension was provided in the file_name config item, use the uploaded one

			if (strpos($this->_file_name_override, '.') === FALSE)

			{

				$this->file_name .= $this->file_ext;

			}



			// An extension was provided, lets have it!

			else

			{

				$this->file_ext	 = $this->get_extension($this->_file_name_override);

			}



			if ( ! $this->is_allowed_filetype(TRUE))

			{

				$this->set_error('upload_invalid_filetype');

				return FALSE;

			}

		}



		// Convert the file size to kilobytes

		if ($this->file_size > 0)

		{

			$this->file_size = round($this->file_size/1024, 2);

		}



		// Is the file size within the allowed maximum?

		if ( ! $this->is_allowed_filesize())

		{

			$this->set_error('upload_invalid_filesize');

			return FALSE;

		}



		// Are the image dimensions within the allowed size?

		// Note: This can fail if the server has an open_basdir restriction.

		if ( ! $this->is_allowed_dimensions())

		{

			$this->set_error('upload_invalid_dimensions');

			return FALSE;

		}



		// Sanitize the file name for security

		$this->file_name = $this->clean_file_name($this->file_name);



		// Truncate the file name if it's too long

		if ($this->max_filename > 0)

		{

			$this->file_name = $this->limit_filename_length($this->file_name, $this->max_filename);

		}



		// Remove white spaces in the name

		if ($this->remove_spaces == TRUE)

		{

			$this->file_name = preg_replace("/\s+/", "_", $this->file_name);

		}



		/*

		 * Validate the file name

		 * This function appends an number onto the end of

		 * the file if one with the same name already exists.

		 * If it returns false there was a problem.

		 */

		$this->orig_name = $this->file_name;



		if ($this->overwrite == FALSE)

		{

			$this->file_name = $this->set_filename($this->upload_path, $this->file_name);



			if ($this->file_name === FALSE)

			{

				return FALSE;

			}

		}



		/*

		 * Run the file through the XSS hacking filter

		 * This helps prevent malicious code from being

		 * embedded within a file.  Scripts can easily

		 * be disguised as images or other file types.

		 */

		if ($this->xss_clean)

		{

			if ($this->do_xss_clean() === FALSE)

			{

				$this->set_error('upload_unable_to_write_file');

				return FALSE;

			}

		}



		/*

		 * Move the file to the final destination

		 * To deal with different server configurations

		 * we'll attempt to use copy() first.  If that fails

		 * we'll use move_uploaded_file().  One of the two should

		 * reliably work in most environments

		 */

		if ( ! @copy($this->file_temp, $this->upload_path.$this->file_name))

		{

			if ( ! @move_uploaded_file($this->file_temp, $this->upload_path.$this->file_name))

			{

				$this->set_error('upload_destination_error');

				return FALSE;

			}

		}



		/*

		 * Set the finalized image dimensions

		 * This sets the image width/height (assuming the

		 * file was an image).  We use this information

		 * in the "data" function.

		 */

		$this->set_image_properties($this->upload_path.$this->file_name);



		return TRUE;

	}



	// --------------------------------------------------------------------



	/**

	 * Finalized Data Array

	 *

	 * Returns an associative array containing all of the information

	 * related to the upload, allowing the developer easy access in one array.

	 *

	 * @return	array

	 */

	public function data()

	{

		return array (

						'file_name'			=> $this->file_name,

						'file_type'			=> $this->file_type,

						'file_path'			=> $this->upload_path,

						'full_path'			=> $this->upload_path.$this->file_name,

						'raw_name'			=> str_replace($this->file_ext, '', $this->file_name),

						'orig_name'			=> $this->orig_name,

						'client_name'		=> $this->client_name,

						'file_ext'			=> $this->file_ext,

						'file_size'			=> $this->file_size,

						'is_image'			=> $this->is_image(),

						'image_width'		=> $this->image_width,

						'image_height'		=> $this->image_height,

						'image_type'		=> $this->image_type,

						'image_size_str'	=> $this->image_size_str,

					);

	}



	// --------------------------------------------------------------------



	/**

	 * Set Upload Path

	 *

	 * @param	string

	 * @return	void

	 */

	public function set_upload_path($path)

	{

		// Make sure it has a trailing slash

		$this->upload_path = rtrim($path, '/').'/';

	}



	// --------------------------------------------------------------------



	/**

	 * Set the file name

	 *

	 * This function takes a filename/path as input and looks for the

	 * existence of a file with the same name. If found, it will append a

	 * number to the end of the filename to avoid overwriting a pre-existing file.

	 *

	 * @param	string

	 * @param	string

	 * @return	string

	 */

	public function set_filename($path, $filename)

	{

		if ($this->encrypt_name == TRUE)

		{

			mt_srand();

			$filename = md5(uniqid(mt_rand())).$this->file_ext;

		}



		if ( ! file_exists($path.$filename))

		{

			return $filename;

		}



		$filename = str_replace($this->file_ext, '', $filename);



		$new_filename = '';

		for ($i = 1; $i < 100; $i++)

		{

			if ( ! file_exists($path.$filename.$i.$this->file_ext))

			{

				$new_filename = $filename.$i.$this->file_ext;

				break;

			}

		}



		if ($new_filename == '')

		{

			$this->set_error('upload_bad_filename');

			return FALSE;

		}

		else

		{

			return $new_filename;

		}

	}



	// --------------------------------------------------------------------



	/**

	 * Set Maximum File Size

	 *

	 * @param	integer

	 * @return	void

	 */

	public function set_max_filesize($n)

	{

		$this->max_size = ((int) $n < 0) ? 0: (int) $n;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Maximum File Name Length

	 *

	 * @param	integer

	 * @return	void

	 */

	public function set_max_filename($n)

	{

		$this->max_filename = ((int) $n < 0) ? 0: (int) $n;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Maximum Image Width

	 *

	 * @param	integer

	 * @return	void

	 */

	public function set_max_width($n)

	{

		$this->max_width = ((int) $n < 0) ? 0: (int) $n;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Maximum Image Height

	 *

	 * @param	integer

	 * @return	void

	 */

	public function set_max_height($n)

	{

		$this->max_height = ((int) $n < 0) ? 0: (int) $n;

	}



	// --------------------------------------------------------------------



	/**

	 * Set Allowed File Types

	 *

	 * @param	string

	 * @return	void

	 */

	public function set_allowed_types($types)

	{

		if ( ! is_array($types) && $types == '*')

		{

			$this->allowed_types = '*';

			return;

		}

		$this->allowed_types = explode('|', $types);

	}



	// --------------------------------------------------------------------



	/**

	 * Set Image Properties

	 *

	 * Uses GD to determine the width/height/type of image

	 *

	 * @param	string

	 * @return	void

	 */

	public function set_image_properties($path = '')

	{

		if ( ! $this->is_image())

		{

			return;

		}



		if (function_exists('getimagesize'))

		{

			if (FALSE !== ($D = @getimagesize($path)))

			{

				$types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');



				$this->image_width		= $D['0'];

				$this->image_height		= $D['1'];

				$this->image_type		= ( ! isset($types[$D['2']])) ? 'unknown' : $types[$D['2']];

				$this->image_size_str	= $D['3'];  // string containing height and width

			}

		}

	}



	// --------------------------------------------------------------------



	/**

	 * Set XSS Clean

	 *

	 * Enables the XSS flag so that the file that was uploaded

	 * will be run through the XSS filter.

	 *

	 * @param	bool

	 * @return	void

	 */

	public function set_xss_clean($flag = FALSE)

	{

		$this->xss_clean = ($flag == TRUE) ? TRUE : FALSE;

	}



	// --------------------------------------------------------------------



	/**

	 * Validate the image

	 *

	 * @return	bool

	 */

	public function is_image()

	{

		// IE will sometimes return odd mime-types during upload, so here we just standardize all

		// jpegs or pngs to the same file type.



		$png_mimes  = array('image/x-png');

		$jpeg_mimes = array('image/jpg', 'image/jpe', 'image/jpeg', 'image/pjpeg');



		if (in_array($this->file_type, $png_mimes))

		{

			$this->file_type = 'image/png';

		}



		if (in_array($this->file_type, $jpeg_mimes))

		{

			$this->file_type = 'image/jpeg';

		}



		$img_mimes = array(

							'image/gif',

							'image/jpeg',

							'image/png',

						);



		return (in_array($this->file_type, $img_mimes, TRUE)) ? TRUE : FALSE;

	}



	// --------------------------------------------------------------------



	/**

	 * Verify that the filetype is allowed

	 *

	 * @return	bool

	 */

	public function is_allowed_filetype($ignore_mime = FALSE)

	{

		if ($this->allowed_types == '*')

		{

			return TRUE;

		}



		if (count($this->allowed_types) == 0 OR ! is_array($this->allowed_types))

		{

			$this->set_error('upload_no_file_types');

			return FALSE;

		}



		$ext = strtolower(ltrim($this->file_ext, '.'));



		if ( ! in_array($ext, $this->allowed_types))

		{

			return FALSE;

		}



		// Images get some additional checks

		$image_types = array('gif', 'jpg', 'jpeg', 'png', 'jpe');



		if (in_array($ext, $image_types))

		{

			if (getimagesize($this->file_temp) === FALSE)

			{

				return FALSE;

			}

		}



		if ($ignore_mime === TRUE)

		{

			return TRUE;

		}



		$mime = $this->mimes_types($ext);



		if (is_array($mime))

		{

			if (in_array($this->file_type, $mime, TRUE))

			{

				return TRUE;

			}

		}

		elseif ($mime == $this->file_type)

		{

				return TRUE;

		}



		return FALSE;

	}



	// --------------------------------------------------------------------



	/**

	 * Verify that the file is within the allowed size

	 *

	 * @return	bool

	 */

	public function is_allowed_filesize()

	{

		if ($this->max_size != 0  AND  $this->file_size > $this->max_size)

		{

			return FALSE;

		}

		else

		{

			return TRUE;

		}

	}



	// --------------------------------------------------------------------



	/**

	 * Verify that the image is within the allowed width/height

	 *

	 * @return	bool

	 */

	public function is_allowed_dimensions()

	{

		if ( ! $this->is_image())

		{

			return TRUE;

		}



		if (function_exists('getimagesize'))

		{

			$D = @getimagesize($this->file_temp);



			if ($this->max_width > 0 AND $D['0'] > $this->max_width)

			{

				return FALSE;

			}



			if ($this->max_height > 0 AND $D['1'] > $this->max_height)

			{

				return FALSE;

			}



			return TRUE;

		}



		return TRUE;

	}



	// --------------------------------------------------------------------



	/**

	 * Validate Upload Path

	 *

	 * Verifies that it is a valid upload path with proper permissions.

	 *

	 *

	 * @return	bool

	 */

	public function validate_upload_path()

	{

		if ($this->upload_path == '')

		{

			$this->set_error('upload_no_filepath');

			return FALSE;

		}



		if (function_exists('realpath') AND @realpath($this->upload_path) !== FALSE)

		{

			$this->upload_path = str_replace("\\", "/", realpath($this->upload_path));

		}



		if ( ! @is_dir($this->upload_path))

		{

			$this->set_error('upload_no_filepath');

			return FALSE;

		}



		if ( ! is_really_writable($this->upload_path))

		{

			$this->set_error('upload_not_writable');

			return FALSE;

		}



		$this->upload_path = preg_replace("/(.+?)\/*$/", "\\1/",  $this->upload_path);

		return TRUE;

	}



	// --------------------------------------------------------------------



	/**

	 * Extract the file extension

	 *

	 * @param	string

	 * @return	string

	 */

	public function get_extension($filename)

	{

		$x = explode('.', $filename);

		return '.'.end($x);

	}



	// --------------------------------------------------------------------



	/**

	 * Clean the file name for security

	 *

	 * @param	string

	 * @return	string

	 */

	public function clean_file_name($filename)

	{

		$bad = array(

						"<!--",

						"-->",

						"'",

						"<",

						">",

						'"',

						'&',

						'$',

						'=',

						';',

						'?',

						'/',

						"%20",

						"%22",

						"%3c",		// <

						"%253c",	// <

						"%3e",		// >

						"%0e",		// >

						"%28",		// (

						"%29",		// )

						"%2528",	// (

						"%26",		// &

						"%24",		// $

						"%3f",		// ?

						"%3b",		// ;

						"%3d"		// =

					);



		$filename = str_replace($bad, '', $filename);



		return stripslashes($filename);

	}



	// --------------------------------------------------------------------



	/**

	 * Limit the File Name Length

	 *

	 * @param	string

	 * @return	string

	 */

	public function limit_filename_length($filename, $length)

	{

		if (strlen($filename) < $length)

		{

			return $filename;

		}



		$ext = '';

		if (strpos($filename, '.') !== FALSE)

		{

			$parts		= explode('.', $filename);

			$ext		= '.'.array_pop($parts);

			$filename	= implode('.', $parts);

		}



		return substr($filename, 0, ($length - strlen($ext))).$ext;

	}



	// --------------------------------------------------------------------



	/**

	 * Runs the file through the XSS clean function

	 *

	 * This prevents people from embedding malicious code in their files.

	 * I'm not sure that it won't negatively affect certain files in unexpected ways,

	 * but so far I haven't found that it causes trouble.

	 *

	 * @return	void

	 */

	public function do_xss_clean()

	{

		$file = $this->file_temp;



		if (filesize($file) == 0)

		{

			return FALSE;

		}



		if (function_exists('memory_get_usage') && memory_get_usage() && ini_get('memory_limit') != '')

		{

			$current = ini_get('memory_limit') * 1024 * 1024;



			// There was a bug/behavioural change in PHP 5.2, where numbers over one million get output

			// into scientific notation.  number_format() ensures this number is an integer

			// http://bugs.php.net/bug.php?id=43053



			$new_memory = number_format(ceil(filesize($file) + $current), 0, '.', '');



			ini_set('memory_limit', $new_memory); // When an integer is used, the value is measured in bytes. - PHP.net

		}



		// If the file being uploaded is an image, then we should have no problem with XSS attacks (in theory), but

		// IE can be fooled into mime-type detecting a malformed image as an html file, thus executing an XSS attack on anyone

		// using IE who looks at the image.  It does this by inspecting the first 255 bytes of an image.  To get around this

		// CI will itself look at the first 255 bytes of an image to determine its relative safety.  This can save a lot of

		// processor power and time if it is actually a clean image, as it will be in nearly all instances _except_ an

		// attempted XSS attack.



		if (function_exists('getimagesize') && @getimagesize($file) !== FALSE)

		{

			if (($file = @fopen($file, 'rb')) === FALSE) // "b" to force binary

			{

				return FALSE; // Couldn't open the file, return FALSE

			}



			$opening_bytes = fread($file, 256);

			fclose($file);



			// These are known to throw IE into mime-type detection chaos

			// <a, <body, <head, <html, <img, <plaintext, <pre, <script, <table, <title

			// title is basically just in SVG, but we filter it anyhow



			if ( ! preg_match('/<(a|body|head|html|img|plaintext|pre|script|table|title)[\s>]/i', $opening_bytes))

			{

				return TRUE; // its an image, no "triggers" detected in the first 256 bytes, we're good

			}

			else

			{

				return FALSE;

			}

		}



		if (($data = @file_get_contents($file)) === FALSE)

		{

			return FALSE;

		}



		$CI =& get_instance();

		return $CI->security->xss_clean($data, TRUE);

	}



	// --------------------------------------------------------------------



	/**

	 * Set an error message

	 *

	 * @param	string

	 * @return	void

	 */

	public function set_error($msg)

	{

		$CI =& get_instance();

		$CI->lang->load('upload');



		if (is_array($msg))

		{

			foreach ($msg as $val)

			{

				$msg = ($CI->lang->line($val) == FALSE) ? $val : $CI->lang->line($val);

				$this->error_msg[] = $msg;

				log_message('error', $msg);

			}

		}

		else

		{

			$msg = ($CI->lang->line($msg) == FALSE) ? $msg : $CI->lang->line($msg);

			$this->error_msg[] = $msg;

			log_message('error', $msg);

		}

	}



	// --------------------------------------------------------------------



	/**

	 * Display the error message

	 *

	 * @param	string

	 * @param	string

	 * @return	string

	 */

	public function display_errors($open = '<p>', $close = '</p>')

	{

		$str = '';

		foreach ($this->error_msg as $val)

		{

			$str .= $open.$val.$close;

		}



		return $str;

	}



	// --------------------------------------------------------------------



	/**

	 * List of Mime Types

	 *

	 * This is a list of mime types.  We use it to validate

	 * the "allowed types" set by the developer

	 *

	 * @param	string

	 * @return	string

	 */

	public function mimes_types($mime)

	{

		global $mimes;



		if (count($this->mimes) == 0)

		{

			if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/mimes.php'))

			{

				include(APPPATH.'config/'.ENVIRONMENT.'/mimes.php');

			}

			elseif (is_file(APPPATH.'config/mimes.php'))

			{

				include(APPPATH.'config//mimes.php');

			}

			else

			{

				return FALSE;

			}



			$this->mimes = $mimes;

			unset($mimes);

		}



		return ( ! isset($this->mimes[$mime])) ? FALSE : $this->mimes[$mime];

	}



	// --------------------------------------------------------------------



	/**

	 * Prep Filename

	 *

	 * Prevents possible script execution from Apache's handling of files multiple extensions

	 * http://httpd.apache.org/docs/1.3/mod/mod_mime.html#multipleext

	 *

	 * @param	string

	 * @return	string

	 */

	protected function _prep_filename($filename)

	{

		if (strpos($filename, '.') === FALSE OR $this->allowed_types == '*')

		{

			return $filename;

		}



		$parts		= explode('.', $filename);

		$ext		= array_pop($parts);

		$filename	= array_shift($parts);



		foreach ($parts as $part)

		{

			if ( ! in_array(strtolower($part), $this->allowed_types) OR $this->mimes_types(strtolower($part)) === FALSE)

			{

				$filename .= '.'.$part.'_';

			}

			else

			{

				$filename .= '.'.$part;

			}

		}



		$filename .= '.'.$ext;



		return $filename;

	}



	// --------------------------------------------------------------------



	/**

	 * File MIME type

	 *

	 * Detects the (actual) MIME type of the uploaded file, if possible.

	 * The input array is expected to be $_FILES[$field]

	 *

	 * @param	array

	 * @return	void

	 */

	protected function _file_mime_type($file)

	{

		// We'll need this to validate the MIME info string (e.g. text/plain; charset=us-ascii)

		$regexp = '/^([a-z\-]+\/[a-z0-9\-\.\+]+)(;\s.+)?$/';



		/* Fileinfo extension - most reliable method

		 *

		 * Unfortunately, prior to PHP 5.3 - it's only available as a PECL extension and the

		 * more convenient FILEINFO_MIME_TYPE flag doesn't exist.

		 */

		if (function_exists('finfo_file'))

		{

			$finfo = finfo_open(FILEINFO_MIME);

			if (is_resource($finfo)) // It is possible that a FALSE value is returned, if there is no magic MIME database file found on the system

			{

				$mime = @finfo_file($finfo, $file['tmp_name']);

				finfo_close($finfo);



				/* According to the comments section of the PHP manual page,

				 * it is possible that this function returns an empty string

				 * for some files (e.g. if they don't exist in the magic MIME database)

				 */

				if (is_string($mime) && preg_match($regexp, $mime, $matches))

				{

					$this->file_type = $matches[1];

					return;

				}

			}

		}



		/* This is an ugly hack, but UNIX-type systems provide a "native" way to detect the file type,

		 * which is still more secure than depending on the value of $_FILES[$field]['type'], and as it

		 * was reported in issue #750 (https://github.com/EllisLab/CodeIgniter/issues/750) - it's better

		 * than mime_content_type() as well, hence the attempts to try calling the command line with

		 * three different functions.

		 *

		 * Notes:

		 *	- the DIRECTORY_SEPARATOR comparison ensures that we're not on a Windows system

		 *	- many system admins would disable the exec(), shell_exec(), popen() and similar functions

		 *	  due to security concerns, hence the function_exists() checks

		 */

		if (DIRECTORY_SEPARATOR !== '\\')

		{

			$cmd = 'file --brief --mime ' . escapeshellarg($file['tmp_name']) . ' 2>&1';



			if (function_exists('exec'))

			{

				/* This might look confusing, as $mime is being populated with all of the output when set in the second parameter.

				 * However, we only neeed the last line, which is the actual return value of exec(), and as such - it overwrites

				 * anything that could already be set for $mime previously. This effectively makes the second parameter a dummy

				 * value, which is only put to allow us to get the return status code.

				 */

				$mime = @exec($cmd, $mime, $return_status);

				if ($return_status === 0 && is_string($mime) && preg_match($regexp, $mime, $matches))

				{

					$this->file_type = $matches[1];

					return;

				}

			}



			if ( (bool) @ini_get('safe_mode') === FALSE && function_exists('shell_exec'))

			{

				$mime = @shell_exec($cmd);

				if (strlen($mime) > 0)

				{

					$mime = explode("\n", trim($mime));

					if (preg_match($regexp, $mime[(count($mime) - 1)], $matches))

					{

						$this->file_type = $matches[1];

						return;

					}

				}

			}



			if (function_exists('popen'))

			{

				$proc = @popen($cmd, 'r');

				if (is_resource($proc))

				{

					$mime = @fread($proc, 512);

					@pclose($proc);

					if ($mime !== FALSE)

					{

						$mime = explode("\n", trim($mime));

						if (preg_match($regexp, $mime[(count($mime) - 1)], $matches))

						{

							$this->file_type = $matches[1];

							return;

						}

					}

				}

			}

		}



		// Fall back to the deprecated mime_content_type(), if available (still better than $_FILES[$field]['type'])

		if (function_exists('mime_content_type'))

		{

			$this->file_type = @mime_content_type($file['tmp_name']);

			if (strlen($this->file_type) > 0) // It's possible that mime_content_type() returns FALSE or an empty string

			{

				return;

			}

		}



		$this->file_type = $file['type'];

	}



	// --------------------------------------------------------------------



}

// END Upload Class



/* End of file Upload.php */

/* Location: ./system/libraries/Upload.php */

