DirectoryInfo.GetDirectories() and attributes

Question

I am using DirectoryInfo.GetDirectories() recursively to find the all the sub-directories under a given path. However, I want to exclude the System folders and there is no clear way for that. In FindFirstFile/FindNextFile things were clearer with the attributes.

Answer 1

@rslite is right, .NET doesn't give such filtering out-of-box, but it's not hard to implement:

static IEnumerable<string> GetNonSystemDirs(string path)
{
    var dirs = from d in Directory.GetDirectories(path)
               let inf = new DirectoryInfo(d)
               where (inf.Attributes & FileAttributes.System) == 0
               select d;

    foreach (var dir in dirs)
    {
        yield return dir;
        foreach (var subDir in GetNonSystemDirs(dir))
        {
            yield return subDir;
        }
    }
}

MSDN links:

FileSystemInfo.Attributes Property

FileAttributes Enumeration