添加获取本地IP工具

Author: hwholiday

other/ip_test.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"testing"
+)
+
+func externalIP() (net.IP, error) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagUp == 0 {
+			continue // interface down
+		}
+		if iface.Flags&net.FlagLoopback != 0 {
+			continue // loopback interface
+		}
+		addrs, err := iface.Addrs()
+		if err != nil {
+			return nil, err
+		}
+		for _, addr := range addrs {
+			ip := getIpFromAddr(addr)
+			if ip == nil {
+				continue
+			}
+			return ip, nil
+		}
+	}
+	return nil, errors.New("connected to the network?")
+}
+
+func getIpFromAddr(addr net.Addr) net.IP {
+	var ip net.IP
+	switch v := addr.(type) {
+	case *net.IPNet:
+		ip = v.IP
+	case *net.IPAddr:
+		ip = v.IP
+	}
+	if ip == nil || ip.IsLoopback() {
+		return nil
+	}
+	ip = ip.To4()
+	if ip == nil {
+		return nil // not an ipv4 address
+	}
+	return ip
+}
+
+func Test_Ip(t *testing.T) {
+	ip, err := externalIP()
+	if err != nil {
+		fmt.Println(err)
+	}
+	fmt.Println(ip.String())
+}