README.md

Console application

Сreating console application

import "github.com/deweppro/go-app/console"

// creating an instance of the application, 
// specifying its name and description for flag: --help 
root := console.New("tool", "help tool")
// adding root command
root.RootCommand(...)
// adding one or more commands
root.AddCommand(...)
// launching the app
root.Exec()

Creating a simple command

import "github.com/deweppro/go-app/console"
// creating a new team with settings
console.NewCommand(func(setter console.CommandSetter) {
	// passing the command name and description
    setter.Setup("simple", "first-level command")
    // description of the usage example
    setter.Example("simple aa/bb/cc -a=hello -b=123 --cc=123.456 -e")
    // description of flags
    setter.Flag(func(f console.FlagsSetter) {
    	// you can specify the flag's name, default value, and information about the flag's value.
        f.StringVar("a", "demo", "this is a string argument")
        f.IntVar("b", 1, "this is a int64 argument")
        f.FloatVar("cc", 1e-5, "this is a float64 argument")
        f.Bool("d", "this is a bool argument")
    })
    // argument validation: specifies the number of arguments, 
    // and validation function that should return 
    // value after validation and validation error
    setter.ArgumentFunc(func(s []string) ([]string, error) {
        if !strings.Contains(s[0], "/") {
            return nil, fmt.Errorf("argument must contain /")
        }
        return strings.Split(s[0], "/"), nil
    })
    // command execution function
    // first argument is a slice of arguments from setter.Argument
    // all subsequent arguments must be in the same order and types as listed in setter.Flag
    setter.ExecFunc(func(args []string, a string, b int64, c float64, d bool) {
        fmt.Println(args, a, b, c, d)
    })
}),

example of execution results

go run main.go --help

Usage: 
  tool  [command] [args]

Available Commands:
  simple    first-level command

_____________________________________________________
Use flag --help for more information about a command.

go run main.go simple --help

Usage: 
  tool simple [arg]  -a=demo -b=1 --cc=1e-05 -d

Flags:
  -a     this is a string argument (default: demo)
  -b     this is a int64 argument (default: 1)
  --cc    this is a float64 argument (default: 1e-05)
  -d     this is a bool argument (default: true)


Examples:
  tool simple aa/bb/cc -a=hello -b=123 --cc=123.456 -e

Creating multi-level command tree

To create a multi-level command tree, you need to add the child command to the parent via the AddCommand method.

At the same time, in the parent command, it is enough to specify only the name and description via the Setup method.

root := console.New("tool", "help tool")

simpleCmd := console.NewCommand(func(setter console.CommandSetter) {
    setter.Setup("simple", "third level")
    ....
})

twoCmd := console.NewCommand(func(setter console.CommandSetter) {
    setter.Setup("two", "second level")
    setter.AddCommand(simpleCmd)
})

oneCmd := console.NewCommand(func(setter console.CommandSetter) {
    setter.Setup("one", "first level")
    setter.AddCommand(twoCmd)
})

root.AddCommand(oneCmd)
root.Exec()

example of execution results

go run main.go --help

Usage: 
  tool  [command] [args]

Available Commands:
  one    first level

_____________________________________________________
Use flag --help for more information about a command.

go run main.go one --help

Usage: 
  tool one [command] [args]

Available Commands:
  two    second level

_____________________________________________________
Use flag --help for more information about a command.

go run main.go one two --help

Usage: 
  tool one two [command] [args]

Available Commands:
  simple    third level

_____________________________________________________
Use flag --help for more information about a command.

go run main.go one two simple --help

Usage: 
  tool one two simple [arg]  -a=demo -b=1 --cc=1e-05 -d

Flags:
  -a     this is a string argument (default: demo)
  -b     this is a int64 argument (default: 1)
  --cc    this is a float64 argument (default: 1e-05)
  -d     this is a bool argument (default: false)


Examples:
  tool simple aa/bb/cc -a=hello -b=123 --cc=123.456 -e