file name changes when i upload i file using do_upload function - php

Question

when i upload a file using do_upload() in code igniter, it uploads the file but it renames it with underscore(_) in the place of blank spaces.
file name to be uploaded: A B C.pdf
file that uploads: A_B_C.pdf
code in controller to upload file:
//$filefeild is the name of folder in which file is to be saved
public function upload_Files($filefeild)
{
//set preferences
$config['upload_path'] = 'assets/bcc/'.$filefeild."/";
$config['allowed_types'] = 'doc|docx|xml|pdf|image|excel|jpg|png|jpeg';
$config['max_size'] = 0;
$config['filname'] = $filenamee = $_FILES[$filefeild]['name'];
$this->upload->initialize($config);
if (!$this->upload->do_upload($filefeild))
{
// case - failure
$upload_error = array('error' => $this->upload->display_errors());
}
else
{
// case - success
$upload_data = $this->upload->data();
$data['success_msg'] = '<div class="alert alert-success text-center">Your file <strong>' . $upload_data['file_name'] . '</strong> was successfully uploaded!</div>';
$filname = $upload_data['file_name'];
return $filenamee;
}
}

Answer 1

IF you see codeigniter's function exist here, you will find following code,
// Remove white spaces in the name
if ($this->remove_spaces === TRUE)
{
$this->file_name = preg_replace('/\s+/', '_', $this->file_name);
}
Which means codeigniter removes spaced and adds _ by default which can be changed by setting config variable. like $config['remove_spaces'] = FALSE;
Secondly if you want your file should be saved with underscors and you get actual name by which file is being saved then in your code you have to make a slight change as described below.
your current code
$config['filname'] = $filenamee = $_FILES[$filefeild]['name'];
Change it to
$config['filname'] = $_FILES[$filefeild]['name'];
and in success scenario get file name from $this->upload->data()
Note: you can find answere here aswell.