title: Are there any invalid linux filenames?
body: <p>If I wanted to create a string which is guaranteed not to represent a filename, I could put one of the following characters in it on Windows:</p>
  
  <pre><code>\ / : * ? | &lt; &gt;
  </code></pre>
  
  <p>e.g.</p>
  
  <pre><code>this-is-a-filename.png
  
  ?this-is-not.png
  </code></pre>
  
  <p>Is there any way to identify a string as 'not possibly a file' on Linux?</p>