correct PHP headers for pdf file download

<?php
header("Content-type:application/pdf");

// It will be called downloaded.pdf
header("Content-Disposition:attachment;filename='downloaded.pdf'");

// The PDF source is in original.pdf
readfile("original.pdf");
?>

$name = 'file.pdf';
//file_get_contents is standard function
$content = file_get_contents($name);
header('Content-Type: application/pdf');
header('Content-Length: '.strlen( $content ));
header('Content-disposition: inline; filename="' . $name . '"');
header('Cache-Control: public, must-revalidate, max-age=0');
header('Pragma: public');
header('Expires: Sat, 26 Jul 1997 05:00:00 GMT');
header('Last-Modified: '.gmdate('D, d M Y H:i:s').' GMT');
echo $content;

<?php

    $filename = './pdf/jobs/pdffile.pdf';

    $fileinfo = pathinfo($filename);
    $sendname = $fileinfo['filename'] . '.' . strtoupper($fileinfo['extension']);

    header('Content-Type: application/pdf');
    header("Content-Disposition: attachment; filename=\"$sendname\"");
    header('Content-Length: ' . filesize($filename));
    readfile($filename);

    header('Content-Description: File Transfer'); 
    header('Content-Type: application/octet-stream'); 
    header('Content-Disposition: attachment; filename="FILENAME"'); 
    header('Content-Transfer-Encoding: binary'); 
    header('Expires: 0'); 
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
    header('Pragma: public'); 
    header('Content-Length: ' . filesize("PATH/TO/FILE")); 
    ob_clean(); 
    flush(); 
    readfile(PATH/TO/FILE);      
    exit();

        $filename='/pdf/jobs/pdffile.pdf';            
        $url_download = BASE_URL . RELATIVE_PATH . $filename;            

        //header("Content-type:application/pdf");   
        header("Content-type: application/octet-stream");                       
        header("Content-Disposition:inline;filename='".basename($filename)."'");            
        header('Content-Length: ' . filesize($filename));
        header("Cache-control: private"); //use this to open files directly                     
        readfile($filename);

header('Content-Length: ' . filesize($file));

header("Content-type:application/pdf");

// It will be called downloaded.pdf thats mean define file name would be show

header("Content-Disposition:attachment;filename=  $fileName  ");

// The PDF source is in original.pdf

readfile($file_url);