cli

README

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a lightweight and simple cli package

Contents

• Get Started
• Commands
  • Parameters
• Help Messages
• Contribute

Get Started

You can use this command to install the package

go get github.com/teamseodo/cli

A example code for the basics of the cli

package main

import "github.com/teamseodo/cli"

func main() {
    mainCommand := cli.NewCommand("app", "app [command] [flags]", "description about the app")

    say := cli.NewCommand("say", "say [flags]", "prints the values")
    mainCommand.AddCommand(say)

    var messageParameter string
    say.AddStringParameter(&cli.Parameter{
        Use: "app print --message [value]",
        Name: "message",
        Shortname: "m",
    }, &messageParameter, "hello world")

    say.Do(func(cmd *cli.Command) {
        fmt.Println(messageParameter)
    })

    help, err := mainCommand.FindHelp(os.Args[1:])
    if err != nil {
        log.Fatal(err)
    }
    help.ShowHelp()

    cmd, err := mainCommand.Parse(os.Args[1:])
    if err != nil {
        log.Fatal(err)
    }

    err = cmd.Run()
    if err != nil {
        cmd.Help().ShowHelp()
    }
}

Commands

You need to create a configurator to use commands or anything in this package. Configurator takes a main command and you can add sub commands to the main command.

You can create a main command like that,

mainCommand := cli.NewCommand("app", "app [command] [flags]", "description about the app")

Every command can have multiple sub commands, you can add a subcommand like that

hi := cli.NewCommand("hi", "hi", "prints a hello message back")
mainCommand.AddCommand(hi)

Now you will get an structure in command line like that,

app hi

If you want to add a functionality to the command, you can use the command.Do method.

hi.Do(func (cmd *cli.Command) {
    fmt.Println("hi")
})

Parse the args after all things are done and run the returned command

cmd, err := mainCommand.Parse(os.Args[1:])
if err != nil {
    log.Fatal(err)
}

err = cmd.Run()
if err != nil {
    cmd.Help().ShowHelp()
}

Now when you type app hi, application will print a "hi" message.

You can add a functionality to the main command either, so it will run when no command is received.

Parameters

Every command can take multiple parameters (also known as: flags) You can add three types of parameters, string, int and bool.

AddBoolParameter(parameter *Parameter, value *bool, defaultValue bool) *Parameter

AddIntParameter(parameter *Parameter, value *int, defaultValue int) *Parameter

AddStringParameter(parameter *Parameter, value *string, defaultValue string) *Parameter

If you want to add a string parameter, you can add the parameter like this

var messageParameter string
printCommand.AddStringParameter(&cli.Parameter{
	Use:       "app print --message [value]",
	Name:      "message",
	Shortname: "m",
}, &messageParameter, "hello world")

Help Messages

If you want to print a help message for the command you need to run the FindHelp() method before configurator initialization.

help, err := mainCommand.FindHelp(os.Args[1:])
if err != nil {
    log.Fatal(err)
}
help.ShowHelp()

When running the wanted command parsing errors can be occur, so you can make an error check when you run the wanted command and print a help.

err = cmd.Run()
if err != nil {
    cmd.Help().ShowHelp()
}

Contribute

Pull requests are welcome. please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

Documentation

Index

• Variables
• type Command
  • func NewCommand(name string, use string, description string) *Command
  • func (c *Command) AddBoolParameter(parameter *Parameter, value *bool, defaultValue bool) *Parameter
  • func (c *Command) AddCommand(command *Command) *Command
  • func (c *Command) AddIntParameter(parameter *Parameter, value *int, defaultValue int) *Parameter
  • func (c *Command) AddStringParameter(parameter *Parameter, value *string, defaultValue string) *Parameter
  • func (c *Command) Do(handler func(cmd *Command))
  • func (c *Command) FindCommand(name string) (*Command, bool)
  • func (c *Command) FindHelp(args []string) (*Help, error)
  • func (c *Command) GetBool(name string) (bool, error)
  • func (c *Command) GetInt(name string) (int, error)
  • func (c *Command) GetString(name string) (string, error)
  • func (c *Command) Help() *Help
  • func (c *Command) Parse(args []string) (*Command, error)
  • func (c *Command) Run() error
• type Commands
• type Help
  • func (help *Help) ShowHelp()
• type Parameter
  • func (p *Parameter) Aliases() []string

Variables

var ErrCommandHandlerNotFound = errors.New("command's handler function is not found")

var ErrCommandNotFound = errors.New("command is not found in configurator's commands")

var ErrParameterIsNotBool = errors.New("wanted parameter is not a boolean")

var ErrParameterIsNotInt = errors.New("wanted parameter is not an integer")

var ErrParameterIsNotString = errors.New("wanted parameter is not a string")

var ErrParameterNotFound = errors.New("wanted parameter is not found")

Types

type Command

type Command struct {
	Name        string
	Use         string
	Description string
	Parameters  []Parameter
	Commands    Commands
	Flagset     *flag.FlagSet
	// contains filtered or unexported fields
}

func NewCommand

func NewCommand(name string, use string, description string) *Command

func (*Command) AddBoolParameter

func (c *Command) AddBoolParameter(parameter *Parameter, value *bool, defaultValue bool) *Parameter

AddBoolParameter sets a bool flag in the command's flagset

func (*Command) AddCommand

func (c *Command) AddCommand(command *Command) *Command

AddCommand adds sub commands to the command

func (*Command) AddIntParameter

func (c *Command) AddIntParameter(parameter *Parameter, value *int, defaultValue int) *Parameter

AddIntParameter sets an int flag in the command's flagset

func (*Command) AddStringParameter

func (c *Command) AddStringParameter(parameter *Parameter, value *string, defaultValue string) *Parameter

AddStringParameter sets a string flag in the command's flagset

func (*Command) Do

func (c *Command) Do(handler func(cmd *Command))

Do sets the command's handler function

func (*Command) FindCommand

func (c *Command) FindCommand(name string) (*Command, bool)

FindCommand searches the sub commands of the command

func (*Command) FindHelp

func (c *Command) FindHelp(args []string) (*Help, error)

FindHelp recognizes if any help command is received and returns a help

func (*Command) GetBool

func (c *Command) GetBool(name string) (bool, error)

GetBool gets a bool value with the given name from the command's flagset

func (*Command) GetInt

func (c *Command) GetInt(name string) (int, error)

GetInt gets an int value with the given name from the command's flagset

func (*Command) GetString

func (c *Command) GetString(name string) (string, error)

GetString gets a string value with the given name from the command's flagset

func (*Command) Help

func (c *Command) Help() *Help

ShowHelp prints the usage of the command

func (*Command) Parse

func (c *Command) Parse(args []string) (*Command, error)

Parse parses the args returns the wanted command

func (*Command) Run

func (c *Command) Run() error

Run runs the command's handler function

type Commands

type Commands []*Command

type Help

type Help struct {
	Usage      string
	Commands   string
	Parameters string
}

func (*Help) ShowHelp

func (help *Help) ShowHelp()

type Parameter

type Parameter struct {
	Name        string
	Shortname   string
	Use         string
	Description string
}

func (*Parameter) Aliases

func (p *Parameter) Aliases() []string

Aliases returns the parameter's other uses