Php / Codeigniter File Download - php

Question

I'm trying to download file in php. I used both codeigniter download helper and pure php code readfile. I can get the contents of file in browser's Network but I can not download it.
When I tried the readfile function in an independent php file it worked.
Here is my code block for dowload file.
// codeigniter
$this->load->helper('download');
$data = file_get_contents(base_url("/images/logo.png"));
force_download($decodedFileInfo->fileName, $data);
// php readfile
$file = "./images/logo.png"; //. $decodedFileInfo->fileName;
if (file_exists($file)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
readfile($file);
exit;
}else{
var_dump("hst");die;
}
Thank you..

Answer 1

Try Saving the file name and image name in variables and echo them on the screen.
I tested this functions works perfectly:
$this->load->dbutil();
//Calling a store procedure
$sp ="exec secondProc '5 Aug 2013'";
$query = $sqlsrvr->query($sp);//->result();
$jawad = $query->result_array();
//pass it to db utility function
$new_report = $this->dbutil->csv_from_result($query);
//Downloading the file
$this->load->helper('download');
force_download('csv_file.csv', $new_report);

Answer 2

header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header('Content-Description: File Transfer');
header("Content-type: text/csv");
header("Content-Disposition: attachment; filename={$name}");
header("Expires: 0");
header("Pragma: public");