Read .DMS file and convert to pdf format in php

Question

Read the file in folder with .DMS extension and convert to pdf format in php

 $path = "folder/1004.dms";
 $content = file_get_contents($path);
 header('Content-type: application/pdf');
 header('Content-Disposition: attachment; filename="test filename.pdf"');
 echo $content;

This code will generate the PDF but it is not opening the pdf file, any help will be appreciated, Thank you.