goflags

An extension of the go flag library that adds convenience functions and functionalities like config file, better usage, short and long flag support, custom types for string slices and maps etc.

Features

• In-built YAML Configuration file support.
• Better usage instructions
• Short and long flags support
• Custom String Slice types with different options (comma-separated,normalized,etc)
• Custom Map type
• Flags grouping support (CreateGroup,SetGroup)

Usage

The following types are supported by the goflags library. The P suffix means that the flag supports both a long and a short flag for the option.

Flag Types

String Slice Options

Example

An example showing various options of the library is specified below.

package main

import (
	"fmt"
	"log"

	"github.com/projectdiscovery/goflags"
)

type options struct {
	silent bool
	inputs goflags.StringSlice
	config string
	values goflags.RuntimeMap
}

const (
	Nil goflags.EnumVariable = iota
	Type1
	Type2
)

func main() {
	enumAllowedTypes := goflags.AllowdTypes{"type1": Type1, "type2": Type2}
	opt := &options{}

	flagSet := goflags.NewFlagSet()
	flagSet.SetDescription("Test program to demonstrate goflags options")

	flagSet.EnumVarP(&options.Type, "enum-type", "et", Nil, "Variable Type (type1/type2)", enumAllowedTypes)
	flagSet.BoolVar(&opt.silent, "silent", true, "show silent output")
	flagSet.StringSliceVarP(&opt.inputs, "inputs", "i", nil, "list of inputs (file,comma-separated)", goflags.FileCommaSeparatedStringSliceOptions)

	update := func(tool string ) func() { 
		return func()  {
			fmt.Printf("%v updated successfully!", tool)
		}
	}
	flagSet.CallbackVarP(update("tool_1"), "update", "up", "update tool_1")


	// Group example
	flagSet.CreateGroup("config", "Configuration",
		flagSet.StringVar(&opt.config, "config", "", "file to read config from"),
		flagSet.RuntimeMapVar(&opt.values, "values", nil, "key-value runtime values"),
	)
	if err := flagSet.Parse(); err != nil {
		log.Fatalf("Could not parse flags: %s\n", err)
	}
	if opt.config != "" {
		if err := flagSet.MergeConfigFile(opt.config); err != nil {
			log.Fatalf("Could not merge config file: %s\n", err)
		}
	}
	fmt.Printf("silent: %v inputs: %v config: %v values: %v\n", opt.silent, opt.inputs, opt.config, opt.values)
}

Thanks

1. spf13/cobra - For the very nice usage template for the command line.
2. nmap/nmap - For the service-port mapping and top-ports list.