roll -- a simple dice-rolling program

roll.go

package main

import (
	"flag"
	"fmt"
	"math/rand"
	"os"
	"time"
)

var iflag = flag.Bool("i", false, "print individual rolls")

func main() {
	flag.Parse()
	rand.Seed(time.Now().UnixNano())

	var s string
	for _, v := range flag.Args() {
		s += v
	}
	var n, x, c int

	_, err := fmt.Sscanf(s, "%dd%d+%d", &n, &x, &c)
	if err != nil {
		fmt.Fprintln(os.Stderr, "roll:", err)
		os.Exit(1)
	}

	roll := make([]int, n)
	for i := range roll {
		roll[i] = rand.Intn(x) + 1
	}

	sum := c
	for _, v := range roll {
		sum += v
	}

	if *iflag {
		fmt.Println(roll, c)
	}
	fmt.Println(sum)
}