Parse command line flags in Go

cmd_flag_parser.go

package main

import (
	"flag"
	"fmt"
)

var hostName = flag.String("host", "localhost", "Hostname or IP you want to run this service on")
var portNumber = flag.Int("port", 8080, "Port you want this service to listen on (default 8080)")

func main() {
	flag.Parse()
	fmt.Println(*hostName)
	fmt.Println(*portNumber)
}

Example: go run cmd_flag_parser.go -host example.com -port 3000