Php download file of any extension from server

[adabonyan]

I am looking for just one php script to download files of any extension in particular doc, docx, pdf, jpg, png, gif.
Either the file will open in a browser or a dialog comes on to save the file
I searched through the internet and got different solution for different extension. Here are 3 examples:

    // This is only good only for pdf 
	$file = 'path/testfile.pdf';
	if (file_exists($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;
	}

//ok only for pdf, docx by changing header Content-type:application
	$file = 'testfile.docx';
	$filename = 'path/testfile.docx';	
	header("Content-type:application/docx");
	header("Content-Disposition:attachment;filename=".$file."");
	readfile($filename);

// saves image file but microsoft office apps, pdf app, etc. cannot open file 
$file = 'path/testfile.jpg';
	$filename = 'testfile.jpg';
	header('Content-type: application/jpg');
	header('Content-Disposition: inline; filename="'.$filename.'"');
	header('Content-Transfer-Encoding: binary');
	header('Accept-Ranges: bytes');
	@readfile($file);

I need just one script to satisfy all types of files

[astonecipher]

create a dictionary of file types. Then when a file is requested, look up the content-type and use the specific type for that document.

[adabonyan]

Thanks. I am trying to avoid this hoping just one script will satisfy all types of files. I will go along your route.

[astonecipher]

It’s still one script, it’s just dynamic to cover possibilities. Everything else stays the same.

[ErnieAlex]

octet-stream

This will allow downloads of any filetype. Just include the filetype in the filename.
( Note: This will NOT force the browser to open in the correct application! )

[adabonyan]

Thanks for all your useful inputs.
I finally used the scirpt below and it works fine for any file format.

$ul = '<ul>';
$dir = ../myfolder/;
$arr = @scandir($dir);
$arr_le = @count($arr);
for ($p=0; $p<$arr_le; $p++) {
  if ($arr[$p] != '.' && $arr[$p] != '..') {
    $path = $dir.$arr[$p];    
    $ul .= '<li><a href="'.$path.'" target="_blank">'.$arr[$p].'</a></li>';
  }
}
$ul .= '</ul>';

$ul is added to the html.
A click on any of the links on the web page will open the file (I noticed this for pdf, jpg, png, gif) and if it cannot, a save dialog box will come up (I noticed this for doc, docx)