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Taking the Color Out ​

Sometimes you need the plain text. Log files, display-width calculations, piping to tools that see ANSI sequences as noise: stripping color is a real use case, and Farben covers it.

ansi_strip! - the Idiomatic Way ​

If you're already using farben::prelude::*, ansi_strip! is right there. It takes the same arguments as format!, formats the string, then strips any ANSI sequences before returning.

rust
use farben::prelude::*;

let colored = "\x1b[31mError\x1b[0m";
let plain = ansi_strip!("{}", colored);
assert_eq!(plain, "Error");

// format args work exactly as you'd expect
let code = 42;
let plain = ansi_strip!("\x1b[1mcode {code}\x1b[0m");
assert_eq!(plain, "code 42");

The return type is String. No extra imports, no intermediate variables.

TIP

ansi_strip! is the right call when you want to format and strip in one step. If you already have a &str and just want to clean it, reach for strip_ansi from farben_core instead.

strip_ansi - Lower-Level Control ​

For cases where you're holding a pre-colored string and want to strip it without going through a format step, farben_core::strip::strip_ansi takes a &str and returns a String.

rust
use farben_core::strip::strip_ansi;

let colored = "\x1b[31mred text\x1b[0m";
assert_eq!(strip_ansi(colored), "red text");

What Gets Stripped ​

strip_ansi targets CSI sequences specifically: ESC [ <params> <letter> (the sequences responsible for colors, bold, underline, and other SGR attributes). Things like \x1b[31m, \x1b[0m, \x1b[1;4m.

Bare ESC bytes not followed by [ are passed through unchanged:

rust
use farben_core::strip::strip_ansi;

let bare_esc = "\x1bhello";
assert_eq!(strip_ansi(bare_esc), "\x1bhello");

INFO

This is intentional. Non-CSI escape sequences serve other purposes (terminal mode switching, cursor movement outside of CSI, etc.). Stripping them blindly would corrupt output that uses those sequences legitimately.

When to Strip ​

A few situations where this comes up:

  • Log files. Your terminal output looks great colored, but writing those bytes to a file produces unreadable noise for anything reading it back as plain text.
  • Display width. ANSI sequences contribute zero visible characters but real byte count. Strip first, then measure with something like unicode-width.
  • Interop. Feeding colored output to a tool (grep, awk, a Slack webhook, a CI log parser) that doesn't know about ANSI.
rust
use farben::prelude::*;
use std::fs::OpenOptions;
use std::io::Write;

let message = cformat!("[red]error:[/] file not found.");

// print in color to the terminal
cprintln!("[red]error:[/] file not found.");

// write plain to the log
let plain = ansi_strip!("{}", message);
let mut log = OpenOptions::new().append(true).open("app.log")?;
writeln!(log, "{plain}")?;

:::note Runtime Farben already has TTY detection! :::