Project Description

AlphaFS is a .NET library providing more complete Win32 file system functionality to the .NET platform than the standard System.IO classes. Features highlights: creating hardlinks, accessing hidden volumes, enumeration of volumes, transactional file operations and much more.


2014-01-23 Since the release of the 1.5 version, many bug fixes and enhancements have been made.
Therefor, you are encouraged to download the latest development build.
Downloadable from here:

The compiled AlphaFS.dll can be found inside the archive: AlphaFS\Development\AlphaFS\Bin


AlphaFS 1.5 Stable Released

AlphaFS has now reached a stable state. Many improvements and bugfixes has been made since the beta and it is now considered stable enough for production use.


The file system support in .NET is pretty good for most uses. However there are a few shortcomings, which this library tries to alleviate. The most notable deficiency of the standard .NET System.IO is the lack of support of advanced NTFS features.
The sister project, AlphaVSS, was created to add Windows Volume Shadow Copy Service (VSS) native functionality to managed .NET applications. VSS creates snapshots of volumes, but on Windows XP does not allow exposing this snapshot as a standard drive letter. There is a hack using the CreateDosDevice Win32 API function, but the solution is not very elegant.

Exposing drive letters works on Windows Vista and later, but it may not be desireable from eg. a backup application, to suddenly have a number of new drive letters turn up in explorer. The paths through which the shadow copies are available are extended-length paths, eg. "\\?\Volume{12345678-aac3-31de-3321-3124565341ed}\Program Files" instead of simply "C:\Program Files". However, these paths cannot be accessed using the file system functions exposed by System.IO.

What does AlphaFS provide?

AlphaFS provides a namespace (Alphaleonis.Win32.Filesystem) containing a number of classes. Most notable are replications of the System.IO.File, System.IO.Directory and System.IO.Path, all with support for the extended-length paths (up to 32000 chars), recursive file enumerations, native backups and manipulations with advanced flags and options. They also contain extensions to these, and there are many more features for several functions.

Another thing AlphaFS brings to the table is support for transactional NTFS (TxF). Almost every method in these classes exist in two versions. One normal, and one that can work with transactions, more specifically the kernel transaction manager. This means that file operations can be performed using the simple, lightweight KTM on NTFS file systems, through .NET, using the interface of the standard classes we are all used to.

AlphaFS also contains some NTFS security related functionality (in Alphaleonis.Win32.Security), providing the ability to enable token privileges for a user, which may be necessary for eg. changing ownership of a file.

The library comes with full API documentation in CHM, Windows Help 2.x and newer 3.x format.

The library is Open Source, licensed under the MIT license.

Last edited Feb 20 at 10:24 AM by Yomodo, version 12