no_color is a zero dependency rust library for NO_COLOR environment variable detection.

From no-color.org:

An increasing number of command-line software programs output text with ANSI color escape codes by default. While some developers and users obviously prefer seeing these colors, many users don’t. Unfortunately, every new piece of software seems to have a different way of disabling colored text output and some software has no way at all.

Accepting the futility of trying to reverse this trend, an informal standard is hereby proposed:

All command-line software which outputs text with ANSI color added should check for the presence of a NO_COLOR environment variable that, when present (regardless of its value), prevents the addition of ANSI color.

By adopting this standard, users that prefer to have plain, non-colored text output can set one environment variable in their shell to have it automatically affect all supported software.

no_color is a library crate which works with Cargo.

To use, add the following to your Cargo.toml dependencies section:

[dependencies]
no_color = "0.2"

or use cargo add:

cargo add no_color

Suggested updates to your rust code as below:

• Note as of edition 2018 extern is not needed to import a crate.

• See examples/simple.rs for reference.

extern crate no_color;
use no_color::*;
fn main() {
    println!(
        "Environment variable NO_COLOR {0} found. Now do something.",
        {
            if is_no_color() {
                "is"
            } else {
                "is NOT"
            }
        }
    );
}