How to display pdf in php

Question

I\'m trying to display a pdf file in php, I used:

Answer 1

if(isset($_GET['content'])){
  $content = $_GET['content'];
  $dir = $_GET['dir'];
  header("Content-type:".$content);
  @readfile($dir);
}

$directory = (file_exists("mydir/"))?"mydir/":die("file/directory doesn't exists");// checks directory if existing.
 //the line above is just a one-line if statement (syntax: (conditon)?code here if true : code if false; )
 if($handle = opendir($directory)){ //opens directory if existing.
   while ($file = readdir($handle)) { //assign each file with link  tag with GET params
     echo ''.$file.'';
}

}

if you click the link a new window will appear with the pdf file