I stumbled on the answer. I am still working through why it works. Here is my code.
<?php
$fname = isset($_POST['fname']) ? $_POST['fname'] : "";
$lname = isset($_POST['lname']) ? $_POST['lname'] : "";
$path = "$fname*$lname.pdf";
$a = glob($path);
$b=($a[0]);
$cd=($b);
$cc = ("$cd");
header('Content-type: application/pdf');
header('Content-Disposition: inline; filename="' . $cc . '"');
header("Content-Length: " . filesize($a));
header('Content-Transfer-Encoding: binary');
header('Accept-Ranges: bytes');
readfile($cc);
?>