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<?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 */