Enumerating Files Throwing Exception

I came across the same problem just today. I hacked together the following code. If you want to use it in a real product you might need to improve the error handling. Since this was for a one-shot script I didn't care much.

static IEnumerable<string> EnumerateFilesRecursive(string root,string pattern="*")
{
    var todo = new Queue<string>();
    todo.Enqueue(root);
    while (todo.Count > 0)
    {
        string dir = todo.Dequeue();
        string[] subdirs = new string[0];
        string[] files = new string[0];
        try
        {
            subdirs = Directory.GetDirectories(dir);
            files = Directory.GetFiles(dir, pattern);
        }
        catch (IOException)
        {
        }
        catch (System.UnauthorizedAccessException)
        {
        }

        foreach (string subdir in subdirs)
        {
            todo.Enqueue(subdir);
        }
        foreach (string filename in files)
        {
            yield return filename;
        }
    }
}

To use it you can either:

string[] files = EnumerateFilesRecursive(@"C:\").ToArray();//Note the ToArray()
foreach (string file in files)
{
   Console.WriteLine(file);
}

which first enumerates all files, stores all file names in memory and only then displays them. Alternatively you can:

IEnumerable<string> files = EnumerateFilesRecursive(@"C:\");//Note that there is NO ToArray()
foreach (string file in files)
{
   Console.WriteLine(file);
}

Which writes while enumerating and thus doesn't need to keep all filenames in memory at the same time.