ping.go

package main

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

func main() {

	rand.Seed(time.Now().UnixNano())

	if len(os.Args) < 2 {
		fmt.Printf("Usage: ping [-aAbBdDfhLnOqrRUvV] [-c count] [-i interval] [-I interface]\n\t[-m mark] [-M pmtudisc_option] [-l preload] [-p pattern] [-Q tos]\n\t[-s packetsize] [-S sndbuf] [-t ttl] [-T timestamp_option]\n\t[-w deadline] [-W timeout] [hop1 ...] destination\n")
		return
	}

	target := os.Args[1]

	ip, err := net.ResolveIPAddr("ip4", target)
	if err != nil {
		fmt.Printf("error: %v\n", err)
		os.Exit(1)
	}

	fmt.Printf("PING %s (%s) 56(84) bytes of data.\n", target, ip.String())
	for i := 0; ; i++ {
		ms := (float64(rand.Intn(154)) / 10)
		fmt.Printf("64 bytes from %s: icmp_seq=%d ttl=54 time=%.1f ms\n", ip.String(), i+1, ms)

		time.Sleep(time.Second - (time.Millisecond * time.Duration(ms)))
	}
}