UnityLongPathPlugin

BepInEx plugin that patches System.IO.File.Move to support Windows long paths (paths longer than MAX_PATH, 260 chars) in Unity games/mods.

Why

Some Unity + modded game workflows still hit path length issues when moving files, especially in deep folder structures. This plugin intercepts file move calls and routes them through a long-path-capable implementation.

Features

• Harmony patch for System.IO.File.Move.
• Windows long-path conversion (\\?\ and \\?\UNC\ handling).
• Drop-in BepInEx plugin (no game-side code changes required).

Requirements

• Windows (plugin relies on kernel32.dll APIs).
• BepInEx 5.x.
• .NET Framework 4.6 target compatibility (net46).

Installation

1. Build the project in Release.
2. Copy UnityLongPathPlugin.dll into your game's BepInEx plugins folder: BepInEx/plugins/
3. Start the game and verify plugin load in BepInEx logs.

Development

dotnet restore UnityLongPathPlugin.sln
dotnet build UnityLongPathPlugin.sln -c Release

Releases

• Tag a version like v1.0.1.
• Push the tag to GitHub.
• The Release workflow builds the plugin, packages it, and publishes a GitHub release asset.

Repository Structure

• UnityLongPathPlugin/Plugin.cs: BepInEx entry point.
• UnityLongPathPlugin/Patcher.cs: Harmony patch registration and File.Move prefix.
• UnityLongPathPlugin/LongFile.cs: Win32 long-path file operations.
• .github/workflows/ci.yml: GitHub Actions CI workflow.
• .github/workflows/release.yml: GitHub Actions release workflow.

Contributing

Contributions are welcome. Please read CONTRIBUTING.md before opening a pull request.

Code of Conduct

Please review CODE_OF_CONDUCT.md when participating in discussions and pull requests.

Security

To report vulnerabilities, see SECURITY.md.

License

This project is licensed under the MIT License. See LICENSE.

Changelog

See CHANGELOG.md for release notes and pending changes.