Attribute Macro command 

#[command]

Add a command to a Clawless application

This macro attribute can be used to register a function as a (sub)command in a Clawless application. The name of the function will be used as the name of the command, and it will be automatically registered as a subcommand under its parent module.

Command functions must accept exactly two parameters:

1. An args parameter: a clap::Args struct with the command’s arguments
2. A context parameter: the Context providing access to the application environment and the cancellation token for cooperative shutdown

Attributes

• alias = "name" - Add a visible alias for the command. Can be repeated for multiple aliases.
• require_subcommand - Require a subcommand; show help if the command is invoked without one.

Requiring Subcommands

Use require_subcommand to create a command that serves as a container for subcommands. When this attribute is set, invoking the command without a subcommand will display help instead of running the command body. This is useful for organizing related commands under a common prefix.

For example, a CLI might have db migrate, db seed, and db reset commands, where db itself requires a subcommand and doesn’t perform any action on its own.

Examples

Basic command:

use clawless::prelude::*;

#[derive(Debug, Args)]
pub struct GreetArgs {
    #[arg(short, long)]
    name: String,
}

#[command]
pub async fn greet(args: GreetArgs, context: Context) -> CommandResult {
    println!("Hello, {}!", args.name);
    Ok(())
}

Command with alias:

use clawless::prelude::*;

#[derive(Debug, Args)]
pub struct GenerateArgs {}

// Users can run `mycli generate` or `mycli g`
#[command(alias = "g")]
pub async fn generate(args: GenerateArgs, context: Context) -> CommandResult {
    Ok(())
}

Command that requires a subcommand:

use clawless::prelude::*;

#[derive(Debug, Args)]
pub struct DbArgs {}

// Running `mycli db` shows help; users must specify a subcommand like `mycli db migrate`
#[command(require_subcommand, alias = "d")]
pub async fn db(args: DbArgs, context: Context) -> CommandResult {
    Ok(())
}