FanControl Hotkey

English | 简体中文

A lightweight hotkey and process-aware profile switcher for FanControl. Written in pure native C with Win32 API, zero external runtime dependencies, and full Per-Monitor V2 High-DPI support.

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✨ Features

• 4 Fan Mode Presets: Silent / Normal / Performance / Turbo
• Custom Hotkey Bindings: Bind any key combination (e.g., Ctrl+Alt+1, Shift+Win+F12)
• Async Process-Aware Auto Switching: Dedicated background worker thread with O(1) FNV-1a hash matching of active processes (e.g., automatically switches to Performance when Cyberpunk2077.exe starts, reverts to Normal on exit)
• GUI Settings Window: Browse and configure FanControl executable path, profile JSONs, hotkeys, and process rules
• Transactional Settings Draft: In-memory draft buffer for settings; Cancel has zero side effects, OK applies changes atomically
• Security Hardened & Robust Storage:
  • Auto-start registry path strictly quoted (\"%s\" %s) and verified against the running binary path
  • Multi-tier INI config persistence: portable .ini next to .exe with automatic %APPDATA%\FanControlHotkey\ fallback for restricted directories
  • External process launching via CreateProcessW with argument escaping and file verification
• Native Wide Character & High-DPI: All internal strings use wchar_t (UTF-16) with manifest-based Per-Monitor V2 DPI scaling
• System Tray & Single Instance: Runs in system tray; re-launching restores existing window to foreground
• Zero Dependencies: Links only Windows system DLLs (USER32, SHELL32, COMDLG32, ADVAPI32, GDI32)

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🛠️ Build & Test

Requirements

• MinGW-w64 (GCC 8.0+, C99/C11 compliant)

Local Compilation

Option 1: PowerShell Script (Recommended)

# Build FanControlHotkey.exe
.\build.ps1

# Run unit tests
.\build.ps1 -Test

# Clean build artifacts
.\build.ps1 -Clean

Option 2: Make

# Build binary
make

# Run unit tests
make test

# Clean artifacts
make clean

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📂 Project Structure

├── .github/workflows/ci.yml   # GitHub Actions CI & Auto-Release pipeline
├── src/                       # Modular C source code
│   ├── main.c                 # Entry point and mutex single-instance check
│   ├── app_context.h          # Global context and data models
│   ├── strings.h / .c         # Bilingual string tables (EN/ZH)
│   ├── config.h / .c          # INI serialization, AppData fallback & autostart
│   ├── hotkey.h / .c          # Hotkey parser and registration manager
│   ├── process_monitor.h / .c # Background thread snapshot & FNV-1a hash matching engine
│   ├── runner.h / .c          # CreateProcessW secure process launcher
│   ├── dpi_utils.h / .c       # Per-Monitor DPI scaling utilities
│   ├── ui_main.h / .c         # Main window (GWLP_USERDATA bound) and message loop
│   └── ui_settings.h / .c     # Modular settings window and hotkey capture
├── tests/
│   └── test_main.c            # Pure C unit test suite
├── res/                       # Resource files
│   ├── app.manifest           # Per-Monitor V2 DPI-Aware manifest
│   ├── resource.h / .rc       # Icon & VERSIONINFO resources
│   └── icon.ico               # Application icon
├── specs/                     # Local archive of specs & decision records (gitignored)
├── build.ps1                  # Windows PowerShell build script
├── Makefile                   # Windows Makefile (MinGW-w64 toolchain)
└── README.md                  # English documentation

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📄 License

This project is licensed under the MIT License.