Rust Password Generator

A very small Rust project that generates simple random passwords.

It's a basic program, but making utilities like this is a rite of passage when learning a new language. So really, this was built to give me a bit of practice with Rust.

The code is included at the bottom of this post.

Usage

Help Info

When called with no arguments, the tool presents help information:

$ passgen

passgen (v0.1.0) Password generator
Usage: passgen <length> <count>

Generating A 16 Character Password

$ passgen 16

qsCbV5znL981zSlW

Generating Several Passwords

$ passgen 16 8

cBOPbcPclBtdyO3F
6UGOoN7qMojrw6Tg
86itbhsuSVtGeLu7
BZCBFK4qma0XR0gA
VFuaElVxveOMhm4I
kxi9Dfq1AhKtn3T5
KYMX5u1JTKvgq0BI
MNGEOUbzuoYq0aFz

The Code

main.rs:

extern crate rand;

use rand::thread_rng;
use rand::Rng;
use rand::distributions::Alphanumeric;

fn generate_passwords(length: &str, count: &str) {
    let length = length.parse::<usize>().expect("[ ERROR ] Invalid password length");
    let count = count.parse::<u8>().expect("[ ERROR ] Invalid number of passwords");
    for _ in 0..count {
        generate_password(length);
    }
}

fn generate_password(length: usize) {
    let rng = thread_rng();
    let password: String = rng.sample_iter(&Alphanumeric).take(length).collect();
    println!("{}", password);
}

fn title() -> String {
    let mut title = String::from(env!("CARGO_PKG_NAME"));
    title.push_str(&format!(" (v{}) ", env!("CARGO_PKG_VERSION")).to_string());
    title.push_str(env!("CARGO_PKG_DESCRIPTION"));
    title
}

fn usage() {
    println!("{}", title());
    println!("Usage: {} <length> <count>", env!("CARGO_PKG_NAME"));
}

fn main() {
    let args: Vec<String> = std::env::args().collect();
    match args.len() {
        3 => generate_passwords(&args[1], &args[2]),
        2 => generate_passwords(&args[1], "1"),
        _ => usage()
    }
}

Cargo.toml:

[package]
name = "passgen"
version = "0.1.0"
edition = "2021"
description = "Password generator"

[dependencies]
rand = "0.7.3"