func init() {
	flag.StringVar(&apikey, "apikey", os.Getenv("VT_API_KEY"), "Set environment variable VT_API_KEY to your VT API Key or specify on prompt")
	flag.StringVar(&apiurl, "apiurl", "https://www.virustotal.com/vtapi/v2/", "URL of the VirusTotal API to be used.")
	flag.StringVar(&rsrc, "rsrc", "", "resource of file to retrieve report for. A resource can be md5, sha-1 or sha-2 sum of a file.")
}
init - initializes flag variables.
package main
import (
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"github.com/williballenthin/govt"
)
var apikey string
var apiurl string
var rsrc string