codeigniter教程之多文件上传使用示例(5)

//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.
      //Check if a filename was supplied for the current file. Otherwise, use it's given name.
      if(!empty($this->_multi_file_name_override[$i])){
       $this->file_name = $this->_prep_filename($this->_multi_file_name_override[$i]);

//If no extension was provided in the file_name config item, use the uploaded one.
       if(strpos($this->_multi_file_name_override[$i], ".") === FALSE){
        $this->file_name .= $this->file_ext;
       //An extension was provided, lets have it!
       } else {
        $this->file_ext = $this->get_extension($this->_multi_file_name_override[$i]);
       }

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;
        }
       }