2 releases

0.2.1 Feb 23, 2024
0.2.0 Aug 30, 2020
0.0.1 Jun 25, 2020

#124 in Operating systems

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There are a number of good random number generator crates in the Rust ecosystem. The point of this crate is to provide something dead simple with no dependencies beyond std by using the OS provided RNG on Unix-like operating systems. Another goal of this crate is to provide a simple interface for creating random strings - a feature that is surprisingly lacking in other random oriented crates.

You might want to use this crate if:

  • Your application does not require a lot of random data early in the boot process
  • You want to attempt to keep the dependency graph for your application small
  • You only care to support Unix-like operating systems


# Cargo.toml
osrand = "0.1"
use osrand::{BufRng, Flags, RandomString};

fn main() {
    // Get a one-off random u32
    let n = osrand::random_u32().unwrap();
    println!("Number: {n}");

    // Get a random u64 from the reusable `BufRng` struct
    let mut rng = BufRng::new().unwrap();
    let n = rng.get_u64().unwrap();
    println!("Number: {n}");

    // Get a random String using the full dictionary
    let mut rs = RandomString::new(&[]).unwrap();
    let s = rs.gen(8).unwrap();
    assert_eq!(s.len(), 8);
    println!("String: {s}");

    // Get the dictionary used by the `RandomString` generator
    let dict = rs.get_dictionary().clone();
    println!("Dictionary: {dict:?}");

    // Change the dictionary to only alphanumeric
    println!("Dictionary: {:?}", rs.get_dictionary());

    // Convert the previous `BufRng` to a `RandomString` with the full dictionary
    let mut rs_new: RandomString = rng.into();

    // Convert the previous `RandomString` to a `BufRng`
    let mut rng_new: BufRng = rs.into();


By default /dev/urandom is used as it is less resource intensive than pulling from /dev/random. If you want a more secure RNG you can go ahead and pull from /dev/random by building with --no-default-features or disabling the urandom feature.

No runtime deps