Print command line flags

flags.go

package main

import (
	"fmt"
	"os"
)

func main() {
	if len(os.Args) > 1 && os.Args[1] == "--help" {
		args := "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
		fmt.Printf("Usage:\n\n%s [--] [%s]...\n\n", os.Args[0], args)
		out := "Args:\n --  prints space\n"
		for _, r := range args {
			ch := string(r)
			out += fmt.Sprintf(" -%s  prints %s\n", ch, ch)
		}
		fmt.Print(out)
		return
	}

	var runes []rune
	for _, arg := range os.Args[1:] {
		if arg == "--" {
			runes = append(runes, ' ')
			continue
		}

		for _, r := range arg {
			if r != '-' {
				runes = append(runes, r)
			}
		}
	}
	fmt.Println(string(runes))
}