codeigniter教程之多文件上传使用示例

 /**
  * multi-upload
  *
  * extends codeigniters native upload class to add support for multiple
  * uploads.
  *
  * @package  codeigniter
  * @subpackage libraries
  * @category uploads
  */
  class my_upload extends ci_upload {

   /**
    * properties
    */
     protected $_multi_upload_data   = array();
    protected $_multi_file_name_override = "";

   /**
    * initialize preferences
    *
    * @access public
    * @param array
    * @return void
    */
    public function initialize($config = array()){
     //upload default settings.
     $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"  => ""
        );

     //set each configuration.
     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;
      }
     }

     //check if file_name was provided.
     if(!empty($this->file_name)){
      //multiple file upload.
      if(is_array($this->file_name)){
       //clear file name override.
       $this->_file_name_override = "";

       //set multiple file name override.
       $this->_multi_file_name_override = $this->file_name;
      //single file upload.
      } else {
       //set file name override.
       $this->_file_name_override = $this->file_name;

       //clear multiple file name override.
       $this->_multi_file_name_override = "";
      }
     }
    }

   /**
    * file mime type
    *
    * detects the (actual) mime type of the uploaded file, if possible.
    * the input array is expected to be $_files[$field].
    *
    * in the case of multiple uploads, a optional second argument may be
    * passed specifying which array element of the $_files[$field] array
    * elements should be referenced (name, type, tmp_name, etc).
    *
    * @access protected
    * @param $file array
    * @param $count int
    * @return void
    */
    protected function _file_mime_type($file, $count=0){
     //mutliple file?
     if(is_array($file["name"])){
      $tmp_name = $file["tmp_name"][$count];
      $type = $file["type"][$count];
     //single file.
     } else {
      $tmp_name = $file["tmp_name"];
      $type = $file["type"];
     }

     //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)){
        $mime = @finfo_file($finfo, $tmp_name);
        finfo_close($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 !== "\\"){
        $cmd = "file --brief --mime ".escapeshellarg($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")){
       $this->file_type = @mime_content_type($tmp_name);
       //it's possible that mime_content_type() returns false or an empty string.
       if(strlen($this->file_type) > 0){
        return;
       }
      }

      //if all else fails, use $_files default mime type.
      $this->file_type = $type;
    }

   /**
    * set multiple upload data
    *
    * @access protected
    * @return void
    */
    protected function set_multi_upload_data(){
     $this->_multi_upload_data[] = 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
     );
    }

   /**
    * get multiple upload data
    *
    * @access public
    * @return array
    */
    public function get_multi_upload_data(){
     return $this->_multi_upload_data;
    }

   /**
    * multile file upload
    *
    * @access public
    * @param string
    * @return mixed
    */
    public function do_multi_upload($field){
     //is $_files[$field] set? if not, no reason to continue.
     if(!isset($_files[$field])){ return false; }

     //is this really a multi upload?
     if(!is_array($_files[$field]["name"])){
      //fallback to do_upload method.
      return $this->do_upload($field);
     }

     //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;
     }

     //every file will have a separate entry in each of the $_files associative array elements (name, type, etc).
     //loop through $_files[$field]["name"] as representative of total number of files. use count as key in
     //corresponding elements of the $_files[$field] elements.
     for($i=0; $i<count($_files[$field]["name"]); $i++){
      //was the file able to be uploaded? if not, determine the reason why.
      if(!is_uploaded_file($_files[$field]["tmp_name"][$i])){
       //determine error number.
       $error = (!isset($_files[$field]["error"][$i])) ? 4 : $_files[$field]["error"][$i];

       //set error.
       switch($error){
        //upload_err_ini_size
        case 1:
         $this->set_error("upload_file_exceeds_limit");
        break;
        //upload_err_form_size
        case 2:
         $this->set_error("upload_file_exceeds_form_limit");
        break;
        //upload_err_partial
        case 3:
         $this->set_error("upload_file_partial");
        break;
        //upload_err_no_file
        case 4:
         $this->set_error("upload_no_file_selected");
        break;
        //upload_err_no_tmp_dir
        case 6:
         $this->set_error("upload_no_temp_directory");
        break;
        //upload_err_cant_write
        case 7:
         $this->set_error("upload_unable_to_write_file");
        break;
        //upload_err_extension
        case 8:
         $this->set_error("upload_stopped_by_extension");
        break;
        default:
         $this->set_error("upload_no_file_selected");
        break;
       }

       //return failed upload.
       return false;
      }

      //set current file data as class variables.
      $this->file_temp = $_files[$field]["tmp_name"][$i];
      $this->file_size = $_files[$field]["size"][$i];
      $this->_file_mime_type($_files[$field], $i);
      $this->file_type = preg_replace("/^(.+?);.*$/", "\\1", $this->file_type);
      $this->file_type = strtolower(trim(stripslashes($this->file_type), '"'));
      $this->file_name = $this->_prep_filename($_files[$field]["name"][$i]);
      $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.
      //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;
        }
       }

      /* 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);

      //set current file data to multi_file_upload_data.
      $this->set_multi_upload_data();
     }

     //return all file upload data.
     return true;
   }
  }