代码语言：javascript复制
package main
import (
"flag"
"fmt"
"io"
"net"
"net/http"
"os"
)
var get_ip = flag.String("get_ip", "", "external|internal")
func main() {
fmt.Println("Usage of ./getmyip --get_ip=(external|internal)")
flag.Parse()
if *get_ip == "external" {
get_external()
}
if *get_ip == "internal" {
get_internal()
}
}
func get_external() {
resp, err := http.Get("http://myexternalip.com/raw")
if err != nil {
os.Stderr.WriteString(err.Error())
os.Stderr.WriteString("n")
os.Exit(1)
}
defer resp.Body.Close()
io.Copy(os.Stdout, resp.Body)
os.Exit(0)
}
func getinternal() {
addrs, err := net.InterfaceAddrs()
if err != nil {
os.Stderr.WriteString("Oops:" err.Error())
os.Exit(1)
}
for , a := range addrs {
if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
if ipnet.IP.To4() != nil {
os.Stdout.WriteString(ipnet.IP.String() "n")
}
}
}
os.Exit(0)
}</pre> 
