Как сделать PDF файл загружаемым в HTML ссылке?

<a href="./directory/yourfile.pdf" download="newfilename">Download the pdf</a>

<a href="./directory/yourfile.pdf" download>Download the pdf</a>

<a href="pdf_server.php?file=pdffilename">Download my eBook</a>

header("Content-Type: application/octet-stream");

$file = $_GET["file"] .".pdf";
header("Content-Disposition: attachment; filename=" . urlencode($file));   
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");
header("Content-Description: File Transfer");            
header("Content-Length: " . filesize($file));
flush(); // this doesn't really matter.
$fp = fopen($file, "r");
while (!feof($fp))
{
    echo fread($fp, 65536);
    flush(); // this is essential for large downloads
} 
fclose($fp); 

$file = $_GET["file"];
if (file_exists($file)) {
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header("Content-Type: application/force-download");
    header('Content-Disposition: attachment; filename=' . urlencode(basename($file)));
    // header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header('Content-Length: ' . filesize($file));
    ob_clean();
    flush();
    readfile($file);
    exit;
}

ForceType applicaton/octet-stream
Header set Content-Disposition attachment

<p>Thanks for downloading! If your download doesn't start shortly, 
<a id="downloadLink" href="...yourpdf.pdf" target="_blank" 
type="application/octet-stream" download="yourpdf.pdf">click here</a>.</p>

var delay = 3000;
window.setTimeout(function(){$('#downloadLink')[0].click();},delay);

<a download href="file.pdf">Download PDF</a> 

header("Content-Type: application/octet-stream");

function downloadFile(src){
    var link=document.createElement('a');
    document.body.appendChild(link);
    link.href= src;
    link.download = '';
    link.click();
}

    File Uploader  
    <script src="../Script/angular1.3.8.js"></script>  
    <script src="../Script/angular-route.js"></script>  
    <script src="../UserScript/MyApp.js"></script>  
    <script src="../UserScript/FileUploder.js"></script>  

        .percent {  
            position: absolute;  
            width: 300px;  
            height: 14px;  
            z-index: 1;  
            text-align: center;  
            font-size: 0.8em;  
            color: white;  
        }  

        .progress-bar {  
            width: 300px;  
            height: 14px;  
            border-radius: 10px;  
            border: 1px solid #CCC;  
            background-image: -webkit-gradient(linear, left top, left bottom, from(#6666cc), to(#4b4b95));  
            border-image: initial;  
        }  

        .uploaded {  
            padding: 0;  
            height: 14px;  
            border-radius: 10px;  
            background-image: -webkit-gradient(linear, left top, left bottom, from(#66cc00), to(#4b9500));  
            border-image: initial;  
        }  



    <div>  
        <table ="width:100%;border:solid;">  
            <tr>  
                <td>Select File</td>  
                <td>  
                    <input type="file" ng-model-instant id="fileToUpload" onchange="angular.element(this).scope().setFiles(this)" />  
                </td>  
            </tr>  
            <tr>  
                <td>File Size</td>  
                <td>  
                    <div ng-repeat="file in files.slice(0)">  
                        <span ng-switch="file.size  1024*1024">  
                            <span ng-switch-when="true">{{file.size / 1024 / 1024 | number:2}} MB</span>  
                            <span ng-switch-default>{{file.size / 1024 | number:2}} kB</span>  
                        </span>  
                    </div>  
                </td>  
            </tr>             
            <tr>  
                <td>  
                    File Attach Status  
                </td>  
                <td>{{AttachStatus}}</td>  
            </tr>  
            <tr>  
                <td>  
                    <input type="button" value="Upload" ng-click="fnUpload();" />  
                </td>  
                <td>  
                    <input type="button" value="DownLoad" ng-click="fnDownLoad();" />  
                </td>  
            </tr>  
        </table>  
    </div>  

  Header set Content-Disposition attachment

header("Content-Type: application/octet-stream");

$file = $_GET["file"] .".pdf";
$path = $_GET["path"];
$fullfile = $path.$file;

header("Content-Disposition: attachment; filename=" . Urlencode($file));   
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");
header("Content-Description: File Transfer");            
header("Content-Length: " . Filesize($fullfile));
flush(); // this doesn't really matter.
$fp = fopen($fullfile, "r");
while (!feof($fp))
{
    echo fread($fp, 65536);
    flush(); // this is essential for large downloads
} 
fclose($fp);

<?php
$local_file = 'file.zip';
$download_file = 'name.zip';

// set the download rate limit (=> 20,5 kb/s)
$download_rate = 20.5;
if(file_exists($local_file) && is_file($local_file))
{
header('Cache-control: private');
header('Content-Type: application/octet-stream');
header('Content-Length: '.filesize($local_file));
header('Content-Disposition: filename='.$download_file);

flush();
$file = fopen($local_file, "r");
while(!feof($file))
{
    // send the current file part to the browser
    print fread($file, round($download_rate * 1024));
    // flush the content to the browser
    flush();
    // sleep one second
    sleep(1);
}
fclose($file);}
else {
die('Error: The file '.$local_file.' does not exist!');
}

?>

def index

 respond_to do |format|
   format.html # Your HTML view
   format.pdf { render :layout => false }
 end
end