Markup for the Terminal

What Is Farben

Farben is a color library that uses markup-like syntax. Color your terminal without typing whatever the heck \x1b[31m is.

Documentation

• User Guide: https://razkar-studio.github.io/farben
• API Reference: https://docs.rs/farben
• Changelog: CHANGELOG.md

Usage

// Using default features
use farben::prelude::*;

style!("error", "[bold underline red]");
style!("warn",  "[bold yellow]");

cprintln!("[error]error: [/]Something bad happened.");
cprintln!("[warn]warn: [/]This looks suspicious.");
cprintln!("[bg:blue fg:white]White on blue!");

let name = "Razkar";
cprintln!("[bold green]Hello, {}!", name);

cprintb!("[red]This bleeds ");
cprintln!("into this.");

// Using the "compile" feature
use farben::prelude::*;

cprintln!("[bold underline red]error: [/]Something bad happened."); // compile-time validation
cprintln!("[bg:blue fg:white]White on blue!");

let name = "Razkar";
cprintln!("[bold green]Hello, {}!", name);

cprintb!("[red]This bleeds ");
cprintln!("into this.");

Features

• Markup-like Syntax: Easy to read, write, and powerful when used.
• Zero required runtime dependencies: Only farben-core as a path dependency, Farben introduces no complicated dependency tree.
• Opt-in Compile-time Processing: Validate and process markup at compile time with no runtime overhead, via the compile feature flag.
• Complete Toolkit: Named colors, ANSI256, RGB, emphasis styles, style chaining, foreground and background support.
• Drop-in Print Macros: cprint!, cprintln!, cprintb!, cprintbln! work just like print! and println! but with markup support. Writer variants cwrite!, cwriteln!, cwriteb!, cwritebln! work with any Write implementor.
• Stderr Variants: All print macros have e variants (ceprint!, ceprintln!, etc.) that target stderr.
• Bleed Variants: cprintb!, cprintbln!, colorb(), and colorb!() skip the trailing reset, letting styles carry forward across multiple calls.
• User-defined styles: Define your own tags with style!() that expand to any combination of supported tags.
• Custom style files: Drop in a name.frb.toml file, write 1 line on build.rs and 2 on main.rs, and all styles from that file is set.

Known Limitations

• No NO_COLOR, FORCE_COLOR, or TTY detection, in compile. The compile feature processes markup at build time and bakes ANSI codes directly into the binary. As a result, NO_COLOR, FORCE_COLOR, and TTY detection are only respected at build time, not at end-user runtime. They are fundamentally different, and I cannot solve this. Use runtime macros if you need full environment awareness.

Note

Update, compile-time style thingy works now I guess. Check the docs for how they work.

Syntax

Tags are written as [tag] and apply from that point forward. Multiple tags can be combined in a single bracket: [bold red].

Warning

Spaces inside ansi() and rgb() are not supported at the moment.

Tag	Description
[red], [blue], ...	Named colors (black, red, green, yellow, blue, magenta, cyan, white)
[fg:red], [bg:red]	Explicit foreground/background color — works with all color formats
[rgb(r,g,b)]	24-bit RGB color
[ansi(n)]	256-color palette index
[bold], [italic], [dim], [underline], [blink], [strikethrough]	Emphasis styles
[/]	Reset all styles
\\[	Escaped bracket, treated as literal [
[yourname]	User-defined style via style!()

Error Handling

color() panics on invalid markup. For graceful error handling, use try_color():

use farben::try_color;

match try_color("[invalid]oops") {
    Ok(s) => println!("{s}"),
    Err(e) => eprintln!("Error: {e}"),
}

Contributing

Contributions are welcome! Feel free to submit a Pull Request.

License

Licensed under either of MIT License or Apache License, Version 2.0 at your option.

Cheers, RazkarStudio.
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