CLAMSHELL

Comfortable clamshell mode for Linux

What is clamshell mode?

Clamshell mode allows you to work with your laptop lid closed, using an external monitor, keyboard, and mouse.

How to enable clamshell mode

Required

• At least one external monitor is connected
• The laptop lid is closed

Optional

• The laptop is connected to AC power TODO

Comparison

macOS and systemd-based implementations require AC power as an absolute condition for clamshell mode, but clamshell does not. It also does not depend on any init system, so it works in any environment.

Installation

To install, you need xmake, cmake, ninja, and gcc.

For systemd users

chmod +x service/systemd/install.sh
service/systemd/install.sh

After installation, enable clamshell with the following commands:

sudo systemctl restart systemd-logind
sudo systemctl enable --now clamshell

A configuration file that disables systemd's control of the lid will be created at /etc/systemd/logind.conf.d/clamshell.conf.
To uninstall clamshell, delete /etc/systemd/logind.conf.d/clamshell.conf to restore systemd's lid control.

For OpenRC users

chmod +x service/openrc/install.sh
service/openrc/install.sh

After installation, enable clamshell with the following commands:

sudo rc-update add clamshell default
sudo rc-service clamshell start

Other init systems

Contributions are welcome ;)

Configuration

The configuration file is in TOML format and is loaded in the following order: ~/.config/clamshell/config.conf → /etc/clamshell/config.conf

fallback

Whether to automatically fall back to another mode if the mode specified by suspend_mode_type is unavailable.
Default: false

suspend_mode_type

The suspend method to use.
Default: freeze

Value	Description
freeze	Freezes the CPU. The lightest option and works in most environments.
suspend_to_ram	Uses RAM suspend (S3).
suspend_to_disk	Uses disk suspend (hibernation).

nvidia_method_type

The suspend method to use when an NVIDIA GPU is present.
Default: official_script

Value	Description
official_script	Uses /usr/bin/nvidia-sleep.sh This is the recommended option.
direct_proc	Directly uses /proc/driver/nvidia/suspend Not recommended due to instability.

Roadmap

• Turn off the laptop display using DPMS
• Allow user configuration via D-Bus
• Add AC power connection as an optional condition