How To Upload Multiple files Using CodeIgniter ?

This is just an extension to the existing Codeigniter's Upload class to take advantage of multiple uploads in one form field.

Installation Copy MY_Upload.php to your application/libraries directory. If you are using a prefix other than MY_ for your classes and/or alternative file paths, adjust accordingly.

Usage Load the Upload class as usual, in your controller call the function do_multi_upload(). If you are uploading a single file, it'll default to the regular do_upload() method. In the form, set field names to array (e.g. name="userfile[]")

MY_Upload.php

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

/**
 * Exenstion File Uploading Class
 */
  
class MY_Upload extends CI_Upload {
 
 public function do_multi_upload( $field = 'userfile', $return_info = TRUE, $filenames = NULL ){

  // Is $_FILES[$field] set? If not, no reason to continue.
  if ( ! isset($_FILES[$field]))
  {   
   $this->set_error('upload_no_file_selected');
   return FALSE;   
  }
  
  //If not every file filled was used, clear the empties
  
  foreach( $_FILES[$field]['name'] as $k => $n )
  { 
   if( empty( $n ) )
   {
   
    foreach( $_FILES[$field] as $kk => $f )
    {    
     unset( $_FILES[$field][$kk][$k] );     
    }        
   }   
  }
  
  // Is the upload path valid?
  if ( ! $this->validate_upload_path($field) )
  {

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

  //Multiple file upload
  if( is_array( $_FILES[$field] ) )
  { 
   //$count = count($_FILES[$field]['name']); //Number of files to process
   
   foreach( $_FILES[$field]['name'] as $k => $file )
   {    
    // Was the file able to be uploaded? If not, determine the reason why.
    if ( ! is_uploaded_file($_FILES[$field]['tmp_name'][$k] ) )
    {     
     $error = ( ! isset($_FILES[$field]['error'][$k])) ? 4 : $_FILES[$field]['error'][$k];
     
     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'][$k];
    $this->file_size = $_FILES[$field]['size'][$k];
    $this->file_type = preg_replace("/^(.+?);.*$/", "\\1", $_FILES[$field]['type'][$k]);
    $this->file_type = strtolower(trim(stripslashes($this->file_type), '"'));
    
    if(empty($filenames))
    {
     $this->file_name = $this->_prep_filename($_FILES[$field]['name'][$k]);     
    }
    else
    {
     $this->file_name = $this->_prep_filename($filenames[$k]);
    }
    
    $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);
  
    
    if( $return_info === TRUE )
    {     
     $return_value[$k] = $this->data();    
    }
    else
    {    
     $return_value = TRUE;    
    }    
   }
   
   return $return_value;  
  }
  else //Single file upload, rely on native CI upload class
  {  
   $upload = self::do_upload();   
   return $upload;  
  } 
 }

}

?>

Source: https://github.com/nicdev/CodeIgniter-Multiple-File-Upload