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

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

A very simple solution, returns a list of files.

    public static List<string> AllFilesInFolder(string folder)
    {
        var result = new List<string>();

        foreach (string f in Directory.GetFiles(folder))
        {
            result.Add(f);
        }

        foreach (string d in Directory.GetDirectories(folder))
        {
            result.AddRange(AllFilesInFolder(d));
        }

        return result;
    }

This one helped me to get all files in a directory and sub directories, May be helpful for someone. [ Inspired from above answers ]

static void Main(string[] args)
    {
        try
        {
            var root = @"G:\logs";
            DirectorySearch(root);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        Console.ReadKey();
    }





public static void DirectorySearch(string root, bool isRootItrated = false)
{
    if (!isRootItrated)
    {
        var rootDirectoryFiles = Directory.GetFiles(root);
        foreach (var file in rootDirectoryFiles)
        {
            Console.WriteLine(file);
        } 
    }

    var subDirectories = Directory.GetDirectories(root);
    if (subDirectories?.Any() == true)
    {
        foreach (var directory in subDirectories)
        {
            var files = Directory.GetFiles(directory);
            foreach (var file in files)
            {
                Console.WriteLine(file);
            }
            DirectorySearch(directory, true);
        }
    }
}

I prefer to use DirectoryInfo because I can get FileInfo's, not just strings.

        string baseFolder = @"C:\temp";
        DirectoryInfo di = new DirectoryInfo(baseFolder);

        string searchPattern = "*.xml";

        ICollection<FileInfo> matchingFileInfos = di.GetFiles(searchPattern, SearchOption.AllDirectories)
            .Select(x => x)
            .ToList();

I do this in case in the future I need future filtering..based on the properties of FileInfo.

        string baseFolder = @"C:\temp";
        DirectoryInfo di = new DirectoryInfo(baseFolder);

        string searchPattern = "*.xml";

        ICollection<FileInfo> matchingFileInfos = di.GetFiles(searchPattern, SearchOption.AllDirectories)
            .Where(x => x.LastWriteTimeUtc < DateTimeOffset.Now)
            .Select(x => x)
            .ToList();

I can also resort back to strings if need be. (and still am future proofed for filters/where-clause stuff.

        string baseFolder = @"C:\temp";
        DirectoryInfo di = new DirectoryInfo(baseFolder);

        string searchPattern = "*.xml";

        ICollection<string> matchingFileNames = di.GetFiles(searchPattern, SearchOption.AllDirectories)
            .Select(x => x.FullName)
            .ToList();

Note that "." is a valid search pattern if you want to filer by extension.

Short and simple solution

string dir = @"D:\PATH";

DateTime from_date = DateTime.Now.Date;
DateTime to_date = DateTime.Now.Date.AddHours(23);
var files = Directory.EnumerateFiles(dir, "*.*",SearchOption.AllDirectories).Select(i=>new FileInfo(i))
.Where(file=>file.LastWriteTime >= from_date && file.LastWriteTime <= to_date);
foreach(var fl in files)
    Console.WriteLine(fl.FullName);

Some excellent answers but these answers did not solve my issue.

As soon as a folder permission issue arises: "Permission Denied" the code fails. This is what I used to get around the "Permission Denied" issue:

private int counter = 0;

    private string[] MyDirectories = Directory.GetDirectories("C:\\");

    private void ScanButton_Click(object sender, EventArgs e)
    {
        Thread MonitorSpeech = new Thread(() => ScanFiles());
        MonitorSpeech.Start();
    }

    private void ScanFiles()
    {
        string CurrentDirectory = string.Empty;

        while (counter < MyDirectories.Length)
        {
            try
            {
                GetDirectories();
                CurrentDirectory = MyDirectories[counter++];
            }
            catch
            {
                if (!this.IsDisposed)
                {
                    listBox1.Invoke((MethodInvoker)delegate { listBox1.Items.Add("Access Denied to : " + CurrentDirectory); });
                }
            }
        }
    }

    private void GetDirectories()
    {
        foreach (string directory in MyDirectories)
        {
            GetFiles(directory);
        }
    }

    private void GetFiles(string directory)
    {
        try
        {
            foreach (string file in Directory.GetFiles(directory, "*"))
            {
                listBox1.Invoke((MethodInvoker)delegate { listBox1.Items.Add(file); });
            }
        }
        catch
        {
            listBox1.Invoke((MethodInvoker)delegate { listBox1.Items.Add("Access Denied to : " + directory); });
        }
    }

Hope this helps others.

Here is a version of B. Clay Shannon's code not static for excel-files:

class ExcelSearcher
{
    private List<string> _fileNames;

    public ExcelSearcher(List<string> filenames)
    {
        _fileNames = filenames;
    }
    public List<string> GetExcelFiles(string dir, List<string> filenames = null)
    {

        string dirName = dir;
        var dirNames = new List<string>();
        if (filenames != null)
        {
            _fileNames.Concat(filenames);
        }
        try
        {
            foreach (string f in Directory.GetFiles(dirName))
            {
                if (f.ToLower().EndsWith(".xls") || f.ToLower().EndsWith(".xlsx"))
                {
                    _fileNames.Add(f);
                }
            }
            dirNames = Directory.GetDirectories(dirName).ToList();
            foreach (string d in dirNames)
            {
                GetExcelFiles(d, _fileNames);
            }
        }
        catch (Exception ex)
        {
            //Bam
        }
        return _fileNames;
    }

var d = new DirectoryInfo(@"C:\logs");
var list = d.GetFiles("*.txt").Select(m => m.Name).ToList();

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

If you only need filenames and since I didn't really like most of the solutions here (feature-wise or readability-wise), how about this lazy one?

private void Foo()
{
  var files = GetAllFiles("pathToADirectory");
  foreach (string file in files)
  {
      // Use can use Path.GetFileName() or similar to extract just the filename if needed
      // You can break early and it won't still browse your whole disk since it's a lazy one
  }
}

/// <exception cref="T:System.IO.DirectoryNotFoundException">The specified path is invalid (for example, it is on an unmapped drive).</exception>
/// <exception cref="T:System.UnauthorizedAccessException">The caller does not have the required permission.</exception>
/// <exception cref="T:System.IO.IOException"><paramref name="path" /> is a file name.-or-A network error has occurred.</exception>
/// <exception cref="T:System.IO.PathTooLongException">The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters and file names must be less than 260 characters.</exception>
/// <exception cref="T:System.ArgumentNullException"><paramref name="path" /> is null.</exception>
/// <exception cref="T:System.ArgumentException"><paramref name="path" /> is a zero-length string, contains only white space, or contains one or more invalid characters as defined by <see cref="F:System.IO.Path.InvalidPathChars" />.</exception>
[NotNull]
public static IEnumerable<string> GetAllFiles([NotNull] string directory)
{
  foreach (string file in Directory.GetFiles(directory))
  {
    yield return file; // includes the path
  }

  foreach (string subDir in Directory.GetDirectories(directory))
  {
    foreach (string subFile in GetAllFiles(subDir))
    {
      yield return subFile;
    }
  }
}

private void GetFiles(DirectoryInfo dir, ref List<FileInfo> files)
{
    try
    {
        files.AddRange(dir.GetFiles());
        DirectoryInfo[] dirs = dir.GetDirectories();
        foreach (var d in dirs)
        {
            GetFiles(d, ref files);
        }
    }
    catch (Exception e)
    {

    }
}

Listing files and folders to model, custom implementation.
This creates a full listing of all files and folders starting from your start directory.

public class DirOrFileModel
    {
        #region Private Members

        private string _name;
        private string _location;
        private EntryType _entryType;

        #endregion

        #region Bindings

        public string Name
        {
            get { return _name; }
            set
            {
                if (value == _name) return;
                _name = value;
            }
        }

        public string Location
        {
            get { return _location; }
            set
            {
                if (value == _location) return;
                _location = value;
            }
        }

        public EntryType EntryType
        {
            get { return _entryType; }
            set
            {
                if (value == _entryType) return;
                _entryType = value;
            }
        }

        public ObservableCollection<DirOrFileModel> Entries { get; set; }

        #endregion

        #region Constructor

        public DirOrFileModel()
        {
            Entries = new ObservableCollection<DirOrFileModel>();
        }

        #endregion
    }

    public enum EntryType
    {
        Directory = 0,
        File = 1
    }

Method:

 static DirOrFileModel DirSearch(DirOrFileModel startDir)
        {
            var currentDir = startDir;
            try
            {
                foreach (string d in Directory.GetDirectories(currentDir.Location))
                {
                    var newDir = new DirOrFileModel
                    {
                        EntryType = EntryType.Directory,
                        Location = d,
                        Name = Path.GetFileName(d)
                    };
                    currentDir.Entries.Add(newDir);

                    DirSearch(newDir);
                }

                foreach (string f in Directory.GetFiles(currentDir.Location))
                {
                    var newFile = new DirOrFileModel
                    {
                        EntryType = EntryType.File,
                        Location = f,
                        Name = Path.GetFileNameWithoutExtension(f)
                    };
                    currentDir.Entries.Add(newFile);
                }

            }
            catch (Exception excpt)
            {
                Console.WriteLine(excpt.Message);
            }
            return startDir;
        }

Usage:

var dir = new DirOrFileModel
            {
                Name = "C",
                Location = @"C:\",
                EntryType = EntryType.Directory
            };

            dir = DirSearch(dir);

To avoid the UnauthorizedAccessException, I use:

var files = GetFiles(@"C:\", "*.*", SearchOption.AllDirectories);
foreach (var file in files)
{
    Console.WriteLine($"{file}");
}

public static IEnumerable<string> GetFiles(string path, string searchPattern, SearchOption searchOption)
{
    var foldersToProcess = new List<string>()
    {
        path
    };

    while (foldersToProcess.Count > 0)
    {
        string folder = foldersToProcess[0];
        foldersToProcess.RemoveAt(0);

        if (searchOption.HasFlag(SearchOption.AllDirectories))
        {
            //get subfolders
            try
            {
                var subfolders = Directory.GetDirectories(folder);
                foldersToProcess.AddRange(subfolders);
            }
            catch (Exception ex)
            {
                //log if you're interested
            }
        }

        //get files
        var files = new List<string>();
        try
        {
            files = Directory.GetFiles(folder, searchPattern, SearchOption.TopDirectoryOnly).ToList();
        }
        catch (Exception ex)
        {
            //log if you're interested
        }

        foreach (var file in files)
        {
            yield return file;
        }
    }
}

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();

Some improved version with max lvl to go down in directory and option to exclude folders:

using System;
using System.IO;

class MainClass {
  public static void Main (string[] args) {

    var dir = @"C:\directory\to\print";
    PrintDirectoryTree(dir, 2, new string[] {"folder3"});
  }


  public static void PrintDirectoryTree(string directory, int lvl, string[] excludedFolders = null, string lvlSeperator = "")
  {
    excludedFolders = excludedFolders ?? new string[0];

    foreach (string f in Directory.GetFiles(directory))
    {
        Console.WriteLine(lvlSeperator+Path.GetFileName(f));
    } 

    foreach (string d in Directory.GetDirectories(directory))
    {
        Console.WriteLine(lvlSeperator + "-" + Path.GetFileName(d));

        if(lvl > 0 && Array.IndexOf(excludedFolders, Path.GetFileName(d)) < 0)
        {
          PrintDirectoryTree(d, lvl-1, excludedFolders, lvlSeperator+"  ");
        }
    }
  }
}

input directory:

-folder1
  file1.txt
  -folder2
    file2.txt
    -folder5
      file6.txt
  -folder3
    file3.txt
  -folder4
    file4.txt
    file5.txt

output of the function (content of folder5 is excluded due to lvl limit and content of folder3 is excluded because it is in excludedFolders array):

-folder1
  file1.txt
  -folder2
    file2.txt
    -folder5
  -folder3
  -folder4
    file4.txt
    file5.txt

Shortest record

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

static void Main(string[] args)
        {
            string[] array1 = Directory.GetFiles(@"D:\");
            string[] array2 = System.IO.Directory.GetDirectories(@"D:\");
            Console.WriteLine("--- Files: ---");
            foreach (string name in array1)
            {
                Console.WriteLine(name);
            }
            foreach (string name in array2)
            {
                Console.WriteLine(name);
            }
                  Console.ReadLine();
        }

IEnumerable<string> GetFilesFromDir(string dir) =>
 Directory.EnumerateFiles(dir).Concat(
 Directory.EnumerateDirectories(dir)
          .SelectMany(subdir => GetFilesFromDir(subdir)));

Here's my angle on it, based on Hernaldo's, if you need to find files with names of a certain pattern, such as XML files that somewhere in their name contain a particular string:

// call this like so: GetXMLFiles("Platypus", "C:\\");
public static List<string> GetXMLFiles(string fileType, string dir)
{
    string dirName = dir; 
    var fileNames = new List<String>();
    try
    {
        foreach (string f in Directory.GetFiles(dirName))
        {
            if ((f.Contains(fileType)) && (f.Contains(".XML")))
            {
                fileNames.Add(f);
            }
        }
        foreach (string d in Directory.GetDirectories(dirName))
        {
            GetXMLFiles(fileType, d);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
    return fileNames;
}

In Framework 2.0 you can use (It list files of root folder, it's best the most popular answer):

static void DirSearch(string dir)
{
    try
    {
        foreach (string f in Directory.GetFiles(dir))
            Console.WriteLine(f);
        foreach (string d in Directory.GetDirectories(dir))
        {
            Console.WriteLine(d);
            DirSearch(d);
        }

    }
    catch (System.Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}

A simple and clean solution

/// <summary>
/// Scans a folder and all of its subfolders recursively, and updates the List of files
/// </summary>
/// <param name="sFullPath">Full path of the folder</param>
/// <param name="files">The list, where the output is expected</param>
internal static void EnumerateFiles(string sFullPath, List<FileInfo> fileInfoList)
{
    try
    {
        DirectoryInfo di = new DirectoryInfo(sFullPath);
        FileInfo[] files = di.GetFiles();

        foreach (FileInfo file in files)
            fileInfoList.Add(file);

        //Scan recursively
        DirectoryInfo[] dirs = di.GetDirectories();
        if (dirs == null || dirs.Length < 1)
            return;
        foreach (DirectoryInfo dir in dirs)
            EnumerateFiles(dir.FullName, fileInfoList);

    }
    catch (Exception ex)
    {
        Logger.Write("Exception in Helper.EnumerateFiles", ex);
    }
}

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];
            }
        }
    }
}