gocmd

A Go library for building command line applications.

Features

• Advanced command line arguments handling
  • Subcommand handling
  • Short and long command line arguments
  • Multiple arguments (repeated or delimited)
  • Support for environment variables
  • Well formatted usage printing
  • Auto usage and version printing
  • Unknown argument handling
• Output tables in the terminal
• Template support for config files
• No external dependency

Installation

go get github.com/devfacet/gocmd/v3

Usage

A basic app

For the full code click here.

func main() {
	flags := struct {
		Help      bool `short:"h" long:"help" description:"Display usage" global:"true"`
		Version   bool `short:"v" long:"version" description:"Display version"`
		VersionEx bool `long:"vv" description:"Display version (extended)"`
		Echo      struct {
			Settings bool `settings:"true" allow-unknown-arg:"true"`
		} `command:"echo" description:"Print arguments"`
		Math struct {
			Sqrt struct {
				Number float64 `short:"n" long:"number" required:"true" description:"Number"`
			} `command:"sqrt" description:"Calculate square root"`
			Pow struct {
				Base     float64 `short:"b" long:"base" required:"true" description:"Base"`
				Exponent float64 `short:"e" long:"exponent" required:"true" description:"Exponent"`
			} `command:"pow" description:"Calculate base exponential"`
		} `command:"math" description:"Math functions" nonempty:"true"`
	}{}

	// Echo command
	gocmd.HandleFlag("Echo", func(cmd *gocmd.Cmd, args []string) error {
		fmt.Printf("%s\n", strings.Join(cmd.FlagArgs("Echo")[1:], " "))
		return nil
	})

	// Math commands
	gocmd.HandleFlag("Math.Sqrt", func(cmd *gocmd.Cmd, args []string) error {
		fmt.Println(math.Sqrt(flags.Math.Sqrt.Number))
		return nil
	})
	gocmd.HandleFlag("Math.Pow", func(cmd *gocmd.Cmd, args []string) error {
		fmt.Println(math.Pow(flags.Math.Pow.Base, flags.Math.Pow.Exponent))
		return nil
	})

	// Init the app
	gocmd.New(gocmd.Options{
		Name:        "basic",
		Description: "A basic app",
		Version:     fmt.Sprintf("%s (%s)", version, gitCommit),
		Flags:       &flags,
		ConfigType:  gocmd.ConfigTypeAuto,
	})
}

# Build the example app:
make build

# Run it:
gocmdbasic

Usage: basic [options...] COMMAND [options...]

A basic app

Options:
  -h, --help         	Display usage
  -v, --version      	Display version
      --vv           	Display version (extended)

Commands:
  echo               	Print arguments
  math               	Math functions
    sqrt             	Calculate square root
      -n, --number   	Number
    pow              	Calculate base exponential
      -b, --base     	Base
      -e, --exponent 	Exponent

# Try the following commands:
gocmdbasic echo hello world
gocmdbasic math sqrt -n 9
gocmdbasic math pow -b 2 --exponent 2
gocmdbasic -v
gocmdbasic --vv

Test

# Test everything:
make test

# For BDD development:
# It will open a new browser window. Make sure:
#   1. There is no errors on the terminal window.
#   2. There is no other open GoConvey page.
make test-ui

# Benchmarks
make test-benchmarks

Release

# Update and commit CHANGELOG.md first (i.e. git add CHANGELOG.md && git commit -m "v1.0.0").
# Set GIT_TAG using semver (i.e. GIT_TAG=v1.0.0)
make release GIT_TAG=

Contributing

See CONTRIBUTING.md

License

Licensed under The MIT License (MIT)
For the full copyright and license information, please view the LICENSE.txt file.