C# – Find all empty directories

Let’s say you want to search the file system and find all empty directories. An empty directory has the following conditions:

• It has no files.
• It either has no subdirectories -OR- it only has empty subdirectories.

To check if a directory is empty, you have to recursively check all of its subdirectories for any files. Use Directory.EnumerateDirectories() to loop through a directory’s immediate subdirectories, and use Directory.EnumerateFiles().Any() to check for files. The following code shows how to do this:

using System.IO;
using System.Linq;

bool IsDirectoryEmpty(string path)
{
	bool subDirectoriesAreEmpty = true;
	foreach (var subDir in Directory.EnumerateDirectories(path))
	{
		if (IsDirectoryEmpty(subDir))
		{
			Console.WriteLine($"Empty: {subDir}");
		}
		else
		{
			subDirectoriesAreEmpty = false;
		}
	}

	if (subDirectoriesAreEmpty && !Directory.EnumerateFiles(path).Any())
	{
		return true;
	}
	return false;
}
Code language: C# (cs)

Note: You can use this as a starting point for dealing with empty directories however you need to. This is simply outputting the paths to the console.

Now I’ll show an example of running this code against a directory – C:\temp\EmptyTest\ – with the following structure:

As you can see, this directory contains four empty subdirectories. Here’s how to run the code against this directory:

string rootPath = @"C:\temp\EmptyTest\";
Console.WriteLine($"Finding all empty directories in {rootPath}");

if (IsDirectoryEmpty(rootPath))
{
	Console.WriteLine("Empty all the way down");
}
Code language: C# (cs)

This correctly finds the four empty subdirectories and outputs the following:

Finding all empty directories in C:\temp\EmptyTest\
Empty: C:\temp\EmptyTest\B-NotEmpty\BB-Empty
Empty: C:\temp\EmptyTest\C-Empty
Empty: C:\temp\EmptyTest\D-Empty\DD-Empty
Empty: C:\temp\EmptyTest\D-Empty
Code language: plaintext (plaintext)

The root directory is not empty. It contains at least one subdirectory that has files, so by definition, it’s not empty.