c# - How to list all files and folders on a hard drive?

Question

I want to list all files and folders that my program has access to and write them to a text file. How would I get the list? I need a way that will catch or not throw UnauthorizedAccessExceptions on folders that are not accessible.

Solution 1

Please try using the code:

private static IEnumerable<string> Traverse(string rootDirectory)
{
    IEnumerable<string> files = Enumerable.Empty<string>();
    IEnumerable<string> directories = Enumerable.Empty<string>();
    try
    {
        // The test for UnauthorizedAccessException.
        var permission = new FileIOPermission(FileIOPermissionAccess.PathDiscovery, rootDirectory);
        permission.Demand();

        files = Directory.GetFiles(rootDirectory);
        directories = Directory.GetDirectories(rootDirectory);
    }
    catch
    {
        // Ignore folder (access denied).
        rootDirectory = null;
    }

    if (rootDirectory != null)
        yield return rootDirectory;

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

    // Recursive call for SelectMany.
    var subdirectoryItems = directories.SelectMany(Traverse);
    foreach (var result in subdirectoryItems)
    {
        yield return result;
    }
}

Client code:

var paths = Traverse(@"Directory path");
File.WriteAllLines(@"File path for the list", paths);

Solution 2

Try

string[] files = Directory.GetFiles(@"C:\\", "*.*", SearchOption.AllDirectories);

This should give you a array containing all files on the hard disk.

Comments

[derp_in_mouth]

I cannot find a way to list ALL files without getting an UnauthorizedAccessException with this method.

[Jonathan Wood]

You're going to have to give a bit of effort to work through this. Look through the methods as there are ones for getting permissions. But, in the end, you could always trap exceptions and, if you get that exception, then your program knows it cannot access that particular location.

[Eilistraee]

It's because you don't have sufficient rights to access all thedirectories on the hard drive. You should simply wrap the call with try blocks and manage these errors.

[Sergey Vyacheslavovich Brunov]

@aiodintsov, of course! Because of Windows UAC. You can add the manifest for your application (codeproject.com/Articles/17968/…) to use the elevation.

[Maate]

Please consider not using Directory.GetFiles() for retrieving all files on a machine. This method returns an array and thus it will do the whole iteration when you call the method. It will be hard to predict the implications on the client machine and most likely you will use much more client-side resources than you would like. I for sure would not want any code running on my pc that did this. If you really want to enumerate all files on a pc you should consider a much more gentle approach imho, starting with Directory.EnumerateFiles as suggested by @Candie :-)

[Hooman]

Using your provided solution throws Access to the path 'C:\$Recycle.Bin\S-1-5-21-1211431010-2331069801-34201645-100‌​8' is denied.