title: Cross-platform file name handling in .NET Core
body: <p>How to handle file name in <code>System.IO</code> classes in a cross-platform manner to make it work on Windows and Linux?</p>
  
  <p>For example, I write this code that works perfectly on Windows, however it doesn't create a file on Ubuntu Linux:</p>
  
  <pre><code>var tempFilename = $@"..\Data\uploads\{filename}";
  using (FileStream fs = System.IO.File.Create(tempFilename))
  {
      file.CopyTo(fs);
      fs.Flush();                    
  }
  </code></pre>