This crate provides attribute macros for command-line argument parsing.

Usage

Just by adding an attribute #[cmd] to a function, the function is converted to a command line program.

```rust,should_panic

[argopt::cmd]

fn main(host: String, port: u16) { // ... } ```

```text $ cargo run error: The following required arguments were not provided:

USAGE: argopt-test

For more information try --help ```

```text $ cargo run -- --help argopt-test

USAGE: argopt-test

ARGS:

OPTIONS: -h, --help Print help information ```

You can customize the behavior of arguments by annotating them with #[opt(...)] attributes.

```rust,should_panic

[argopt::cmd]

fn main( #[opt(short = 'h', long = "host")] host: String, #[opt(short, long, defaultvaluet = 80)] port: u16, ) { // ... } ```

And you can add help messages by adding doccomments.

```rust,should_panic /// Sample program

[argopt::cmd]

fn main( /// Host name #[opt(short = 'h', long = "host")] host: String, /// Port number #[opt(short, long, defaultvaluet = 80)] port: u16, ) { // ... } ```

You can also use the #[opt(...)] attribute to customize the behavior of an application.

```rust,should_panic /// Sample program

[argopt::cmd]

[opt(author, version, about, long_about = None)]

fn main( /// Host name #[opt(short = 'h', long = "host")] host: String, /// Port number #[opt(short, long, defaultvaluet = 80)] port: u16, ) { // ... } ```

```text $ cargo run -- --help argopt-test 0.1.0 Sample program

USAGE: argopt-test [OPTIONS] --host

OPTIONS: -h, --host Host name --help Print help information -p, --port Port number [default: 80] -V, --version Print version information ```

The available options are the same as those of clap::Parser.

Subcommands

You can create sub commands by adding the attribute #[subcmd] to functions.

```rust,shouldpanic use argopt::{subcmd, cmdgroup}; use std::path::PathBuf;

[subcmd]

fn add( #[opt(short)] interactive: bool, #[opt(short)] patch: bool, files: Vec, ) { // ... }

[subcmd]

fn commit( #[opt(short)] message: Option, #[opt(short)] all: bool, ) { // ... }

[cmd_group(commands = [add, commit])]

[opt(author, version, about, long_about = None)]

fn main() {} ```

Easy Verbosity Level Handling

There is a feature that allows you to interact with the log crate and handle the verbosity level automatically.

```rust use argopt::cmd; use log::*;

[cmd(verbose)]

fn main() { error!("This is error"); warn!("This is warn"); info!("This is info"); debug!("This is debug"); trace!("This is trace"); } ```

```text $ cargo run This is error

$ cargo run -- -v This is error This is warn

$ cargo run -- -vv This is error This is warn This is info

$ cargo run -- -vvv This is error This is warn This is info This is debug

$ cargo run -- -vvvv This is error This is warn This is info This is debug This is trace ```

You can also use verbose option to subcommand application.

```rust,ignore ...

[cmd_group(commands = [add, commit], verbose)]

fn main() {} ```