Delete all folders and subdirectories that doesn't have a file of certain extension

Question

I'm using this solution to delete all empty folders and subdirectories in a certain path:

static void Main(string[] args)
{
    processDirectory(@"c:\temp");
}

private static void processDirectory(string startLocation)
{
    foreach (var directory in Directory.GetDirectories(startLocation))
    {
        processDirectory(directory);
        if (Directory.GetFiles(directory).Length == 0 && 
            Directory.GetDirectories(directory).Length == 0)
        {
            Directory.Delete(directory, false);
        }
    }
}

It works perfectly. But I want to delete all empty folders and also folders which are not empty but also doesn't contain files with the .dvr extension.

For example, my folder has the files:

a.log

b.log

c.dvr

d.dat

So this folder can't be deleted, for it contains a file with the dvr extension.

How can I filter it? (I'm using GTK# but I believe C# code will work, since this solution is a C# code)

Answer 1

Unfortunately error handling is very exception based in IO operations. And Directory.Delete throws an IOException if the directory is not empty. So you'll have to delete the files manually:

private static bool processDirectory(string startLocation)
{
    bool result = true;
    foreach (var directory in Directory.GetDirectories(startLocation))
    {
        bool directoryResult = processDirectory(directory);
        result &= directoryResult;

        if (Directory.GetFiles(directory, "*.dvr").Any())
        {
             result = false;
             continue;
        }

        foreach(var file in Directory.GetFiles(directory))
        {
            try
            {
               File.Delete(file);
            }
            catch(IOException)
            {
               // error handling
               result = directoryResult = false;
            }
        }

        if (!directoryResult) continue;
        try
        {
            Directory.Delete(directory, false);
        }
        catch(IOException)
        {
            // error handling
            result = false;
        }
    }

    return result;
}

Answer 2

I would use Directory.EnumerateFiles to see if a directory contains the file you're looking for. Changing your code to be:

static void Main(string[] args)
{
    processDirectory(@"c:\temp");
}

private static void processDirectory(string startLocation)
{
    foreach (var directory in Directory.GetDirectories(startLocation))
    {
        processDirectory(directory);
        if (Directory.GetDirectories(directory).Length == 0  ||
            Directory.EnumerateFiles(directory, "*.dvr").Length == 0
            )
        {
            Directory.Delete(directory, false);
        }
    }
}

Answer 3

Avitus answer is correct, but since you need it to work in .NET 2.0, you cannot use the EnumerateFiles method, however GetFiles gets the job done nicely. But requires a little more code.

Example:

static void Main(string[] args)
{
    processDirectory(@"c:\temp");
}

private static void processDirectory(string startLocation)
{
    foreach (var directory in Directory.GetDirectories(startLocation))
    {
        processDirectory(directory);

        if (Directory.GetDirectories(directory).Length == 0))
        {
            bool delete = false;

            var files = Directory.GetFiles(directory);
            // This will delete the directory if it contains a file with the Extension
            // of .dvr, regardless if there are other files in there. Might be something you want to change.
            for (int i = 0; i < files.Length && !delete; i++)
            {
                delete = files[i].Extension.Equals(".dvr", StringComparison.OrdinalIgnoreCase);
            }

            if (delete)
            {
                // Recursive must be set to true in order to
                // delete files and sub-directories in the folder.
                // This folder will not have any sub-directories
                // so it's only used to delete the files.
                Directory.Delete(directory, /*recursive*/ true);
            }
        }
    }
}

You could, in the spirit of less code move the Directory.Delete method call within the for loop, if you wanted, then break the loop.