Cargo.toml

[package]
name = "libc_test"
version = "0.1.0"
authors = ["Mateusz Mikuła <mati865@gmail.com>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
libc = { version = "0.2", default-features = false }

main.rs

fn main() {
    let mut timespec = libc::timespec {
        tv_sec: 0,
        tv_nsec: 0,
    };
    unsafe { libc::clock_gettime(libc::CLOCK_REALTIME, &mut timespec) };
    println!("{}\n{:#?}", timespec.tv_nsec, std::time::SystemTime::now());
}