我已经扩展了 Codeigniter 的上传类以完全适合您的需要。在这个类中，我定义了两个方法 validate_upload 和 do_upload。我没有在此文件中编写任何新代码，而是将 do_upload 代码分成两部分。validate_upload 验证上传并在文件未验证时返回 false，并且 do_upload 仅应在 validate_upload 返回 true 时使用。这是代码。
Class My_Upload extends CI_Upload
{
public function __construct(){
parent::__construct();
}
public function validate_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;
}
}
$this->set_image_properties($this->upload_path.$this->file_name);
return TRUE;
}
public function do_upload($field = 'userfile')
{
/*
* 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.
*/
return TRUE;
}
}