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

Question

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

Answer 1

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);
        }
    }
}

Answer 2

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;
    }

Answer 3

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.

Answer 4

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;
    }
  }
}

Answer 5

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

Answer 6

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);
    }
}