platform.rs

#[cfg(all(target_os = "linux"))]
fn are_you_on_linux() {
    println!("You are running linux!");
}

#[cfg(not(target_os = "linux"))]
fn are_you_on_linux() {
    println!("You are *not* running linux!");
}

fn main() {
    are_you_on_linux();
}