title: php - translating "%C3%BC" to ü
body: <p>In a page, I have this reference:</p>
  
  <p><code>&lt;a href="Schulte_Einf%C3%BChrung.pdf"&gt;Page&lt;/a&gt;</code></p>
  
  <p>I've written a function to see if the file that is referenced to exists. But in this case, the file is named</p>
  
  <p><code>Schulte_Einführung.pdf</code></p>
  
  <p>I know that C3 BC is the UTF-8 encoding of ü, but how can I decode <code>%C3%BC</code> and turn it into ü? All the usual functions like <code>utf_decode</code> and so on don't do anything.</p>
  
  <p>I can't change the filename (because I pull it from a backup file), and I also can't change the encoding because then the page could break. So is there a way to compare <code>Schulte_Einf%C3%BChrung.pdf</code> and <code>Schulte_Einführung.pdf</code> so that they will be equal?</p>