smart-lock.fish

Automatically locks or unlocks the screen based on proximity to trusted devices (Wi-Fi, Bluetooth).

Installation

fisher install edouard-lopez/smart-lock.fish

💡 Requirements

Tool	Purpose	Cinnamon (X11)	KDE/GNOME (Wayland)	KDE/GNOME (X11)	Other (X11)
icons-in-terminal	nicer icons	✓	✓	✓	✓
nmcli (via NetworkManager)	request network status	✓	✓	✓	✓
bluetoothctl	request Bluetooth status	✓	✓	✓	✓
loginctl	control lock/unlock	✓	✓	✓	✓
xprintidle	get/set idle time	✓	—	✓	✓
xset	get/set X server settings	✓	—	✓	✓
cinnamon-screensaver-command	control lock/unlock	✓	—	—	—

For Debian/Ubuntu-based systems (X11):

apt install network-manager bluez xprintidle x11-xserver-utils

For Fedora/RHEL-based systems with KDE/GNOME (Wayland):

dnf install NetworkManager bluez #

For Fedora/RHEL-based systems with X11:

dnf install NetworkManager bluez xorg-x11-server-utils xprintidle

What to do after installation

• 1️⃣✅ Configure the trusted devices and idle timeout variables ;
• 2️⃣✅ Usage = run smart_lock_toggle periodically (e.g., via systemd timer or cron) ;
• 3️⃣✅ Display the lock status in your prompt.

1️⃣✅ Configuration

Trusted Devices & Idle Timeout

Set environment variables to define trusted devices and idle timeout.

Variable	Default	Description
SMART_LOCK_BSSIDS	-	List of trusted Wi-Fi BSSIDs as MAC addresses e.g. home Wi-Fi, office Wi-Fi
SMART_LOCK_DEVICES_MACS	-	List of trusted Bluetooth as MAC addresses e.g. smartphone, mouse)
SMART_LOCK_AFTER	180	Idle timeout in seconds

Example configuration in config.fish:

set --universal --export SMART_LOCK_BSSIDS "AA:BB:CC:DD:EE:FF" "BB:CC:DD:EE:FF:AA" 
set --universal --export SMART_LOCK_DEVICES_MACS "CC:DD:EE:FF:AA:BB"
set --universal --export SMART_LOCK_AFTER 300

2️⃣✅ Usage = run periodically

You need to run smart_lock_toggle periodically to check the proximity of trusted devices to update SMART_LOCK_STATUS and trigger screen lock and unlock the screen accordingly.

systemd Timer (Recommended)

Systemd handles environment variables and logging better than cron.

Create systemd service and timer

Create a user-level systemd timer

mkdir -p ~/.config/systemd/user/

Edit ~/.config/systemd/user/smart-lock.service

[Unit]
Description=Smart Lock Toggle Service

[Service]
Type=oneshot
ExecStart=/usr/bin/fish -c 'source $__fish_config_dir/functions/smart_lock_toggle.fish && smart_lock_toggle'

Edit ~/.config/systemd/user/smart-lock.timer

[Unit]
Description=Smart Lock Toggle Timer

[Timer]
OnBootSec=1min
OnUnitActiveSec=1min
Unit=smart-lock.service

[Install]
WantedBy=timers.target

Enable and start the timer

systemctl --user enable --now smart-lock.timer

Crontab

If you prefer cron, use the following.

ℹ️ Note that you may need to set DISPLAY and DBUS_SESSION_BUS_ADDRESS manually if they are not picked up.

# give some context to cron jobs
DISPLAY=:0
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u)/bus 
# run every minute
* * * * * fish -c 'source $__fish_config_dir/functions/smart_lock_toggle.fish && smart_lock_toggle'

3️⃣✅ Finally Prompt

Add the following to your prompt to show lock status:

echo $SMART_LOCK_STATUS

ℹ️ If you didn't customize your fish_right_prompt.fish, you can use ours:

💡 Install our fish_right_prompt

1. Backup existing fish_right_prompt.fish:

   cp $__fish_config_dir/functions/{,__backup_}fish_right_prompt.fish

2. Replace with smart_lock's version:

   cp $__fish_config_dir/functions/{__smart_lock_,}fish_right_prompt.fish

Debugging

You can always run it manually with Fish debugging

set fish_trace 1
smart_lock_toggle
set --erase fish_trace