Automatic light/dark theme switcher for ubuntu 24.04

README.md

Automatic light/dark theme switcher

A script that can switch between light and dark themes either automatically based on time or manually via command-line arguments. It switches to dark theme at night (between 21:00 and 6:00) and light/default by day. Works in ubuntu 24.04.03

Setup

nano ~/.local/bin/theme_switcher.sh
chmod +x ~/.local/bin/theme_switcher.sh

chrontab -e

* * * * * ~/.local/bin/theme_switcher.sh

Usage

./theme_switcher.sh --dark
./theme_switcher.sh --light

# Automatic mode
./theme_switcher.sh

License

This script was created by mojoaxel with the help of Claude Sonnet 3.5 and is licensed under CC0 - No Rights Reserved.

theme_switcher.sh

#!/bin/zsh

# Function to set theme
set_theme() {
	current_theme=$(gsettings get org.gnome.desktop.interface color-scheme)
	if [ $1 = "dark" ]; then
		if [ "$current_theme" != "'prefer-dark'" ]; then
			echo "Switching to dark theme"
			gsettings set org.gnome.desktop.interface color-scheme prefer-dark
		fi
	else
		if [ "$current_theme" != "'default'" ]; then
			echo "Switching to light theme"
			gsettings set org.gnome.desktop.interface color-scheme default
		fi
	fi
}

# Parse command line arguments
for arg in "$@"; do
	case "$arg" in
		-d|--dark)
			set_theme "dark"
			exit 0
			;;
		-l|--light)
			set_theme "light"
			exit 0
			;;
		-*)
			echo "Invalid option: $arg" >&2
			echo "Usage: $0 [-d|--dark] [-l|--light]" >&2
			exit 1
			;;
	esac
done

# If no arguments provided, use time-based switching
# Get current hour (24-hour format)
current_hour=$(date +%H)

# Check if current time is between 21:00 and 06:00
if [ $current_hour -ge 21 ] || [ $current_hour -lt 6 ]; then
	# Set dark theme
	set_theme "dark"
else
	# Set light theme
	set_theme "light"
fi