https://gist.github.com/Maki-Daisuke/59c23945d736a59cc881 の Go言語版

random.go

package main

import "fmt"
import "flag"
import "math/rand"

func main() {
	var opt_no_alpha bool
	var opt_no_digit bool
	var opt_no_unsco bool
	var opt_length int
	var opt_num int

	flag.BoolVar(&opt_no_alpha, "A", false, "Do not use any alpabets")
	flag.BoolVar(&opt_no_digit, "D", false, "Do not use any digits")
	flag.BoolVar(&opt_no_unsco, "U", false, "Do not use any digits")
	flag.IntVar(&opt_length, "l", 12, "Length of generated strings")
	flag.IntVar(&opt_num, "n", 5, "Number of generated strings")
	flag.Parse()

	m := make(map[byte]bool)
	for i := 0; i < flag.NArg(); i++ {
		str := flag.Arg(i)
		for j := 0; j < len(str); j++ {
			m[str[j]] = true
		}
	}

	if !opt_no_alpha {
		for c := 'a'; c <= 'z'; c++ {
			m[byte(c)] = true
		}
		for c := 'A'; c <= 'Z'; c++ {
			m[byte(c)] = true
		}
	}

	if !opt_no_digit {
		for c := '0'; c <= '9'; c++ {
			m[byte(c)] = true
		}
	}

	if !opt_no_unsco {
		m[byte('_')] = true
	}

	chars := make([]byte, 0, len(m))
	for c := range m {
		chars = append(chars, c)
	}

	for i := 0; i < opt_num; i++ {
		for j := 0; j < opt_length; j++ {
			fmt.Printf("%c", chars[rand.Intn(len(chars))])
		}
		fmt.Println()
	}
}