Flager: Lightweight command Line Argument Parser

Crates.io: https://crates.io/crates/flager

Docs.rs: https://docs.rs/flager/0.0.2/flager/

This is a Rust library that helps you parse command-line arguments in your application. It provides a simple and flexible way to define flags, parse their values, and handle different types of arguments.

Features:

• Flags: You can define flags with short and long names, and specify whether they are mandatory or have a default value.
• Parsing: The library can automatically parse the values of the flags and convert them to the desired data type, such as String, PathBuf, bool, and all of the integer types.
• Argument Handling: The library provides three different ways to handle the arguments:
  • Remainder: Collects all the remaining arguments after the flag.
  • SmartRemainder: Collects the arguments until it encounters a new flag.
  • Count: Collects a specific number of arguments.

Usage

Here's an example from examples/01.rs of how to use the library:

use std::{path::PathBuf, ops::Range};
use flager::{Flag, Parser, NArgs};

fn main() {
    let parser = Parser::new();

    let flag = Flag::<i32>::new("-f", "--flag")
        .mandatory()
        .default(420)
        .help("A mandatory integer flag");

    println!("Flag: {value}", value = parser.parse(&flag).unwrap());

    ////////////////////////////////////////

    let flag2 = Flag::<PathBuf>::new("-p", "--path")
        .default("default/path".into())
        .help("An optional path flag");

    println!("Path: {path:?}", path = parser.parse_or_default(&flag2));

    ////////////////////////////////////////

    let flag3 = Flag::<String>::new("-a", "--args")
        .help("Multiple arguments");

    println!("Arguments: {args:?}", args = parser.parse_many(&flag3, NArgs::Remainder));

    ////////////////////////////////////////                         ^ You can read about `NArgs` in `nargs.md`.

    let flag4 = Flag::<Range::<usize>>::new("-r", "--range")
        .help("Multiple arguments");

    println!("Ranges: {ranges:?}", ranges = parser.parse_many(&flag4, NArgs::SmartRemainder));
}

In this example, we define three flags:

• A mandatory integer flag -f or --flag.
• An optional path flag -p or --path.
• A flag -a or --args that can accept multiple arguments.

We then use the Parser to parse the values of these flags and handle the arguments accordingly.

Supported Types

The library supports the following data types:

• String
• PathBuf
• bool
• isize, i8, i16, i32, i64, i128
• usize, u8, u16, u32, u64, u128
• Range<isize>, Range<i8>, Range<i16>, Range<i32>, Range<i64>, Range<i128>
• Range<usize>, Range<u8>, Range<u16>, Range<u32>, Range<u64>, Range<u128>

You can easily add support for other data types by creating a PR to the official repo: https://github.com/rakivo/flag/