How to recursively list all the files in a directory in C#?

Question

Note that in .NET 4.0 there are (supposedly) iterator-based (rather than array-based) file functions built in:

foreach (string file in Directory.EnumerateFiles(path, "*.*", SearchOption.AllDirectories))
{
    Console.WriteLine(file);
}

At the moment I'd use something like below; the inbuilt recursive method breaks too easily if you don't have access to a single sub-dir...; the Queue<string> usage avoids too much call-stack recursion, and the iterator block avoids us having a huge array.

static void Main() {
    foreach (string file in GetFiles(SOME_PATH)) {
        Console.WriteLine(file);
    }
}

static IEnumerable<string> GetFiles(string path) {
    Queue<string> queue = new Queue<string>();
    queue.Enqueue(path);
    while (queue.Count > 0) {
        path = queue.Dequeue();
        try {
            foreach (string subDir in Directory.GetDirectories(path)) {
                queue.Enqueue(subDir);
            }
        }
        catch(Exception ex) {
            Console.Error.WriteLine(ex);
        }
        string[] files = null;
        try {
            files = Directory.GetFiles(path);
        }
        catch (Exception ex) {
            Console.Error.WriteLine(ex);
        }
        if (files != null) {
            for(int i = 0 ; i < files.Length ; i++) {
                yield return files[i];
            }
        }
    }
}

This article covers all you need. Except as opposed to searching the files and comparing names, just print out the names.

It can be modified like so:

static void DirSearch(string sDir)
{
    try
    {
        foreach (string d in Directory.GetDirectories(sDir))
        {
            foreach (string f in Directory.GetFiles(d))
            {
                Console.WriteLine(f);
            }
            DirSearch(d);
        }
    }
    catch (System.Exception excpt)
    {
        Console.WriteLine(excpt.Message);
    }
}

Added by barlop

GONeale mentions that the above doesn't list the files in the current directory and suggests putting the file listing part outside the part that gets directories. The following would do that. It also includes a Writeline line that you can uncomment, that helps to trace where you are in the recursion that may help to show the calls to help show how the recursion works.

            DirSearch_ex3("c:\\aaa");
            static void DirSearch_ex3(string sDir)
            {
                //Console.WriteLine("DirSearch..(" + sDir + ")");
                try
                {
                    Console.WriteLine(sDir);

                    foreach (string f in Directory.GetFiles(sDir))
                    {
                        Console.WriteLine(f);
                    }

                    foreach (string d in Directory.GetDirectories(sDir))
                    {
                        DirSearch_ex3(d);
                    }
                }
                catch (System.Exception excpt)
                {
                    Console.WriteLine(excpt.Message);
                }
            }

Directory.GetFiles("C:\\", "*.*", SearchOption.AllDirectories)

Shortest record

string[] files = Directory.GetFiles(@"your_path", "*.jpg", SearchOption.AllDirectories);

In .NET 4.5, at least, there's this version that is much shorter and has the added bonus of evaluating any file criteria for inclusion in the list:

public static IEnumerable<string> GetAllFiles(string path, 
                                              Func<FileInfo, bool> checkFile = null)
{
    string mask = Path.GetFileName(path);
    if (string.IsNullOrEmpty(mask)) mask = "*.*";
    path = Path.GetDirectoryName(path);
    string[] files = Directory.GetFiles(path, mask, SearchOption.AllDirectories);

    foreach (string file in files)
    {
        if (checkFile == null || checkFile(new FileInfo(file)))
            yield return file;
    }
}

Use like this:

var list = GetAllFiles(mask, (info) => Path.GetExtension(info.Name) == ".html").ToList();