rod: Terminal Dark/Light Mode Detection Tool

Tool for detecting the lightness of the terminal background.

Note: We used to use Terminal Dark and Light Mode detection but now we are using terminal-colorsaurus, so rod works in more terminals.

What is this for?

Detecting the background lightness can be used to select the color palette of TUI/CLI applications. However, only a few applications currently utilize this feature. This tool aims to bridge the gap until those apps do it.

How to use rod

rod offers three ways to integrate with your terminal applications: aliases, direct printing, and environment variable manipulation.

1. Using Aliases

This method works across major shells and is suitable for commands that need extra arguments to set themes.

alias fzf=rod run fzf

2. Using rod print for scripting

For scripting needs, use the rod print command to retrieve the current color scheme.

3. Using rod env for Environment Variable-Based Applications

This method is ideal for applications that read theme settings from environment variables, it needs to be configured shell-specifically, as follows:

fish:

function preexec_rod --on-event fish_preexec
    rod env | source
endy

zsh:

preexec () {
    rod env | source
}

bash

Sadly there is not a proper preexec mechanism in bash. So to use this method within it, you need to either:

• Install bash-preexec which will be something like:

preexec () {
    rod env | source
}

• Use a bash trap:

rod_trap () {
    [ -n "$COMP_LINE" ] && return  # do nothing if completing
    [ "$BASH_COMMAND" = "$PROMPT_COMMAND" ] && return # don't run for $PROMPT_COMMAND
    rod env|source
}
trap 'rod_trap' DEBUG

How to configure it

Configuration goes in ~/.config/rod/config.toml, it will be created if missing when you run rod for the first time. Run rod example to see a full, updated (and hopefully self-explanatory) example.

Installation

You can find pre-build binaries in the releases.