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.netlinqexceptionenumerate

Is there a way of recover from an Exception in Directory.EnumerateFiles?


In .NET 4, there's this Directory.EnumerateFiles() method with recursion that seems handy.
However, if an Exception occurs within a recursion, how can I continue/recover from that and continuing enumerate the rest of the files?

try
{
  var files = from file in Directory.EnumerateFiles("c:\\",
                           "*.*", SearchOption.AllDirectories)
              select new
              {
                File = file
              };

  Console.WriteLine(files.Count().ToString());

}
catch (UnauthorizedAccessException uEx)
{
  Console.WriteLine(uEx.Message);
}
catch (PathTooLongException ptlEx)
{
  Console.WriteLine(ptlEx.Message);
}

Solution

  • I did found a solution to this. By using a stack to push the enumeration results, one can indeed handle the exceptions. Here's a code snippet: (inspired by this article)

    List<string> results = new List<string>();
    string start = "c:\\";
    results.Add(start);
    Stack<string> stack = new Stack<string>();
    
    do
    {
      try
      {
        var dirs = from dir in Directory.EnumerateDirectories(
                         start, "*.*", SearchOption.TopDirectoryOnly)
                    select dir;
    
        Array.ForEach(dirs.ToArray(), stack.Push);
        start = stack.Pop();
        results.Add(start);
      }
      catch (UnauthorizedAccessException ex)
      {
        Console.WriteLine(ex.Message);
        start = stack.Pop();
        results.Add(start);
      }
    
    } while (stack.Count != 0);
    
    foreach (string file in results)
    {
      Console.WriteLine(file);
    }