Idiomatic Go Package for cli subcommands

This package is intended to be used in conjunction with the Go flag package for maping subcommands to their respective flagset.

The primary features of cmd are:

• Use the standerd flag packege. cmd does not implement its own flag parsing. Instead it integrates nicely with the standerd flag package.

• Common API, style and behavior closely follows that of the standers flag packege.

• Minimal feature set, does not attempt to be a "one size fits all" solution.

• Optionaly enable/disable extra command argument support (besides flags) for subcommands.

Install

go get -u github.com/meblum/cmd

Example usage

import (
	"flag"
	"fmt"

	"github.com/meblum/cmd"
)

func main() {
	greeter := greetHandler{
		greetType: "hello",
		greetName: "Anonymous",
	}

	greetFlagSet := flag.NewFlagSet("greet", flag.ExitOnError)
	greetFlagSet.StringVar(&greeter.greetType, "type", greeter.greetType, "greet type (hello|bye)")
	greetFlagSet.StringVar(&greeter.greetName, "name", greeter.greetName, "name to print greeting for")

	version := versionHandler{
		version: "1.0.0",
		verbose: false,
	}

	versionFlagSet := flag.NewFlagSet("version", flag.ExitOnError)
	versionFlagSet.BoolVar(&version.verbose, "verbose", version.verbose, "output version with additional information")

	c := &cmd.CmdSet{}
	c.Add("print greeting", greetFlagSet, greeter, false)
	c.Add("print version", versionFlagSet, version, false)
	c.HandleCmd(nil, flag.ExitOnError)
}

type greetHandler struct {
	greetType string
	greetName string
}

func (g greetHandler) Handle(c *cmd.Cmd) error {
	switch g.greetType {
	case "hello":
		fmt.Printf("Hello, %v! Nice to meet you :)", g.greetName)
	case "bye":
		fmt.Printf("Hello, %v! Nice to meet you :)", g.greetName)
	default:
		return fmt.Errorf("invalid greet type %v, valid options are 'hello' or 'bye'", g.greetType)
	}
	return nil
}

type versionHandler struct {
	version string
	verbose bool
}

func (g versionHandler) Handle(c *cmd.Cmd) error {
	if g.verbose {
		fmt.Printf("You are using Greeter version %v", g.version)
	}
	fmt.Print(g.version)
	return nil
}

See the documentation for more information.

License

MIT - See LICENSE file