XDispDDCSwtchr

Cross‑platform hotkey → DDC/CI switcher.

• ✅ CLI backends: ddcutil (Linux), ddcctl (macOS), ControlMyMonitor.exe (Windows)
• ✅ JSON configuration of models, monitors, and hotkeys
• 🔄 Native backends scaffolding: Windows (implemented), macOS/Linux (stubs)

Quick start

1. Edit XDispDDCSwtchr-Settings.json.
2. Build and run:

# Linux prerequisites for hotkey support
sudo apt-get install libx11-xcb-dev libxtst-dev libxkbcommon-dev libxkbcommon-x11-dev \
     libxinerama-dev libxrandr-dev libxcursor-dev

# Linux/macOS
go build -o xdispddcswtchr ./cmd/xdispddcswtchr
sudo ln -sfn /Library/Preferences/com.apple.windowserver.displays.plist /Library/Preferences/com.apple.windowserver.plist
./xdispddcswtchr

# Windows
go build -o xdispddcswtchr.exe .\cmd\xdispddcswtchr\
.\xdispddcswtchr.exe

By default the CLI backend is used. To prefer the native backend on Windows, set "backend": "native" in the JSON.

Build tags

• No tags: CLI backend (all OSes)
• -tags native: Enable native backend selection logic. Currently Windows native is implemented; macOS/Linux are stubs.

Platform-Specific Notes

Linux (ddcutil CLI backend)

• Requires ddcutil installed: sudo apt-get install ddcutil
• May require i2c-dev kernel module: sudo modprobe i2c-dev
• Verify DDC/CI support: ddcutil detect
• Limitation: ddcutil currently ignores monitor ID and affects all monitors
• Performance: Commands may take 1-2 seconds per execution
• Timeout: 30-second timeout prevents hanging on unsupported monitors

macOS (ddcctl CLI backend)

• Requires ddcctl installed: brew install ddcctl
• Workaround: Some ddcctl builds require a plist symlink:

  sudo ln -sfn /Library/Preferences/com.apple.windowserver.displays.plist \
               /Library/Preferences/com.apple.windowserver.plist

• Monitor ID Format: Use MonitorName@N where N is the display number (e.g., LG45GX950A@4)
• VCP Code 0x60: Input switching uses -i flag for better compatibility
• Timeout: 30-second timeout prevents hanging on unsupported monitors

Windows (ControlMyMonitor CLI backend)

• Requires ControlMyMonitor.exe in PATH
• Monitor ID Format: Use monitor name from ControlMyMonitor (e.g., "\\.\DISPLAY1")
• VCP Code Format: Supports both hex (0x60) and decimal (96)
• Timeout: 30-second timeout prevents hanging on unsupported monitors

Windows (Native backend)

• Enable with "backend": "native" in settings JSON
• Uses Windows DDC/CI API directly (no external tools required)
• Limitation: If multiple physical monitors share one logical display, only the first is controlled
• VCP Code Format: Supports both hex (0x60) and decimal (96)
• Monitor ID Format: Use DISPLAY1, DISPLAY2, etc., or leave empty for first monitor

Troubleshooting

Commands timeout or hang

• Verify your monitor supports DDC/CI (check monitor OSD settings)
• Test manually with platform tools (ddcutil, ddcctl, or ControlMyMonitor.exe)
• Some monitors require DDC/CI to be explicitly enabled in settings

Monitor not responding to commands

• Check that the correct monitor ID is configured
• Verify VCP codes match your monitor's capabilities
• Some monitors only respond when powered on (not in standby)

macOS plist errors

• Run the symlink command shown above
• Ensure you have appropriate permissions

Notes

• Linux may require i2c-dev access for future native backend; for CLI make sure ddcutil works manually.
• macOS requires appropriate entitlement/permissions for low-level IOKit access; CLI uses ddcctl.