Chessar.LongPaths 1.0.0-rc003

Chessar.LongPaths

Chessar.LongPaths is a .NET library that allows you to enable long path support for the main System.IO classes:

FileStream, File, FileInfo, Directory, DirectoryInfo, ... (and others, for example Image.FromFile).

The library is based on replacing the internal NormalizePath and GetFullPathInternal functions from the static Path class. The replacement is done using JMP hooks (thanks to @wledfor2), in which the long path prefix \\?\ or \\?\UNC\ is added. Adding a prefix is done by calling the internal function Path.AddLongPathPrefix. Note also that the addition of such prefixes depends on the UseLegacyPathHandling and BlockLongPaths settings, which must necessarily be false (in the AppContextSwitchOverrides element).

In this case, your code does not need to directly add such prefixes to the paths.

Supported Platforms:

• .NET Framework 4.6.2+ (see .NET Blog)

How to use

1. Add the Chessar.LongPaths NuGet package to the project.
2. In the file app.config, in the section runtime, add:

<configuration>
...
<runtime>
  <AppContextSwitchOverrides value="Switch.System.IO.UseLegacyPathHandling=false;Switch.System.IO.BlockLongPaths=false" />
</runtime>
...

3. In the code (when you start the application or at the beginning of Main) add code:

...
using static Chessar.Hooks;
...

    PatchLongPaths();

4. At the end of the application:

    RemoveLongPathsPatch();

Notes

For the following list of ctors/methods, you must directly specify the prefix of long paths (because they are not supported by this library):

• new DirectorySecurity(String, AccessControlSections)
• new FileSecurity(String, AccessControlSections)
• Directory.GetAccessControl(String[, AccessControlSections])
• File.GetAccessControl(String[, AccessControlSections])
• Directory.Move(String, String)
• Directory.Delete(String[, Boolean]) (at Release build)

for example:

...
using static Chessar.Hooks;
...
    var ds = new DirectorySecurity(path.AddLongPathPrefix(), acs);

Note that Directory.SetCurrentDirectory does not work for long paths, even if a prefix is added.

License

MIT - See LICENSE