argopt

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.

#[cmd]
fn main(host: String, port: u16) {
    // ...
}

The output is:

$ cargo run
error: The following required arguments were not provided:
    <host>
    <port>

USAGE:
    argopt-test <host> <port>

You can customize the behavior of arguments by annotating them with attributes.

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

And you can add help messages by adding doccomments.

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

The output is:

argopt-test 0.1.0
Sample program

USAGE:
    simple [OPTIONS] --host <host>

FLAGS:
        --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -h, --host <host>    Host name
    -p, --port <port>    Port number [default: 80]

You can use the same options as structopt.

Subcommands

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

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

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

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

#[cmd(verbose)]
fn main() {
    error!("This is error");
    warn!("This is warn");
    info!("This is info");
    debug!("This is debug");
    trace!("This is trace");
}

The output is:

$ 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

License: MIT