gocmd

A Go library for building command line applications.

Programming language: Go

License: MIT License

Tags: Command Line     Standard CLI    

Latest version: v3.1.0

README

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

Usage

A basic app

See [basic](examples/basic/main.go) for full code.

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",
        Version:     "1.0.0",
        Description: "A basic app",
        Flags:       &flags,
        ConfigType:  gocmd.ConfigTypeAuto,
    })
}

cd examples/basic/
go build .

$ ./basic
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

Build

go build .

Test

./test.sh

Release

git add CHANGELOG.md # update CHANGELOG.md
./release.sh v1.0.0  # replace "v1.0.0" with new version

git ls-remote --tags # check the new tag

Contributing

• Code contributions must be through pull requests
• Run tests, linting and formatting before a pull request
• Pull requests can not be merged without being reviewed
• Use "Issues" for bug reports, feature requests and discussions
• Do not refactor existing code without a discussion
• Do not add a new third party dependency without a discussion
• Use semantic versioning and git tags for versioning

License

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