1 unstable release

0.1.0 Jan 18, 2021

#197 in Command-line interface

Download history 1/week @ 2021-02-28 2/week @ 2021-03-07 2/week @ 2021-03-21 102/week @ 2021-03-28 7/week @ 2021-04-04 93/week @ 2021-04-11 1/week @ 2021-04-18 20/week @ 2021-04-25 1/week @ 2021-05-02 1/week @ 2021-05-09 2/week @ 2021-05-16 2/week @ 2021-05-23 2/week @ 2021-05-30 3/week @ 2021-06-06

78 downloads per month
Used in eavesdropper_cli

MIT license

206 lines


A simple library for quickly creating a CLI application without dealing with user input parsing.

Pros Cons
Simple to Use Missing Features More Complicated Libraries Have
Provides an Automatic Help Command

User Experience

Users would utilize your commands like so if they were to utilize the example code below:

No flags: hello

Flag: hello -a flag_value

Help Command

This library provides a already implemented help command!

help: Will provide list of commands, their help description, and the number of their flags.

help -c command_name: Will show command help description as well as detailed flag help

help -c command_name -f flag_name: Will show help information for the specific flag of the command specified.

Create a Command

The example below shows how to create an instance of a command by implementing the Command trait.

struct HelloCommand {}

impl cliargs_t::Command for HelloCommand {
    fn execute_command(&self, flags: std::collections::HashMap<std::string::String, std::string::String>) {
        println!("Hello from the command!");

    fn get_information(&self) -> cliargs_t::CommandInformation { 
        return cliargs_t::CommandInformation {
            command_name: "hello",
            command_help: "says hello",
            flags: vec![
                cliargs_t::Flag {
                    identifier: "a",
                    flag_help: "some example flag -a",
                    required: false

The Main Loop

This is an example of a main method that might funnel input through this library. In this example I used the rustyline library to simplify my user input reading, but any user input method would work as long as it is passed in the appropriate format to the handle_input() method.

use std::io::Read;
use rustyline::error::ReadlineError;
use rustyline::Editor;

fn main() {
    let hello_command: Box<cliargs_t::Command> = Box::new(HelloCommand {});
    let mut commands = vec![
    let commander = cliargs_t::Commander::new(&mut commands);

    let mut rl = Editor::<()>::new();
    if rl.load_history("history.txt").is_err() {
        println!("No previous history.");

    loop {
        let readline = rl.readline(">> ");
        match readline {
            Ok(line) => {
            Err(ReadlineError::Interrupted) => {
            Err(ReadlineError::Eof) => {
            Err(err) => {
                println!("Error: {:?}", err);


~19K SLoC