Sub commands

Sub commands can be added using the .command() method. The first argument specifies the name and optionally arguments for your sub command. The arguments may be <required> or [optional] and the last argument may also be variadic. The second argument of the .command() method is optional and can be either the command description or an instance of a Command class. The description can be also defined with the .description() method.

i

❗ The .command() method returns the instance of the added command. If you call the .action() method after the .command() method is called, the action will be registered to the sub command and not to your main command. You can use the .reset() method to get the instance of the parent command back.

There are three ways to specify sub-commands with the .command() method which are explained in the following section.

Chained commands

Sub-command implemented using the .command() method with an action handler.

import { Command } from "https://deno.land/x/cliffy@v0.24.2/command/mod.ts";

await new Command()
  .command(
    "clone <source:string> [destination:string]",
    "Clone a repository into a newly created directory.",
  )
  .option("-r, --recursive", "Clone recursive.")
  .action(({ recursive }, source: string, destination: string) => {
    console.log("clone %s to %s", source, destination, recursive ? " (recursive)", "");
  })
  .parse(Deno.args);Copy

Command instance

The command method accepts as second argument a instance of a command. This way you can move your sub-commands into different files.

import { Command } from "https://deno.land/x/cliffy@v0.24.2/command/mod.ts";

const clone = new Command()
  .arguments("<source:string> [destination:string]")
  .description("Clone a repository into a newly created directory.")
  .action((options: any, source: string, destination: string) => {
    console.log("clone command called");
  });

await new Command()
  .command("clone", clone)
  .parse(Deno.args);Copy

Executable commands

i

⚠️ This is currently work in progress and in an experimental state!

When .executable() is invoked on a sub-command, this tells cliffy you’re going to use a separate executable file for the sub-command. Cliffy will look for a globally installed program with the name program-sub-command, like deno-install, deno-upgrade.

You handle the options for an executable (sub)command in the executable, and don’t declare them at the top-level.

import { Command } from "https://deno.land/x/cliffy@v0.24.2/command/mod.ts";

await new Command()
  .command("install [name]", "install one or more packages").executable()
  .command("search [query]", "search with optional query").executable()
  .command("update", "update installed packages").executable()
  .command("list", "list packages installed").executable()
  .parse(Deno.args);Copy