Windows Batch - How to get the external IP into a

Question

I am making a program that checks if a user's IP is a certain IP address.

Currently, I created a successful internal IP version:

@echo off
set userIp=192.168.90.100
for /f "tokens=4 delims= " %%i in ('route print ^| find " 0.0.0.0"') do set localIp=%%i
for /f "delims=[] tokens=2" %%a in ('ping %computername% -4 -n 1 ^| findstr "["') do set thisip=%%a
goto :Check

:Check
if %localIp%==%userIp% goto :Good
if %thisip%==%userIp% goto :Good
goto :Bad

And I am trying to make the same thing that works with external IPs.

I researched online, and here is what I got so far.

@echo off
for /f "tokens=2 delims=:" %%a IN ('nslookup myip.opendns.com. resolver1.opendns.com ^| findstr /IC:"Address"') do if /i %%a=="10.11.12.13" goto :Good
goto :Bad

I need a bit of help on how to fix this.

Sincerely, djmrminer.

Answer 1

With pure batch/already present tools:
EDIT: changed the batch to properly handle also IPv6 addresses

@Echo off
for /f "tokens=1* delims=: " %%A in (
  'nslookup myip.opendns.com. resolver1.opendns.com 2^>NUL^|find "Address:"'
) Do set ExtIP=%%B
Echo External IP is : %ExtIP%

Reference

Another one with powershell:

@Echo off
For /f %%A in (
  'powershell -command "(Invoke-Webrequest "http://api.ipify.org").content"'
) Do Set ExtIP=%%A
Echo External IP is : %ExtIP%

Answer 2

First it seems there is a . too much after the first .com.

Second when using your command with simply google.com and echo %a I get the following:

" xx.xx.xx.x" without the quotes and with two leading spaces!

So your if will never be true!

Change it to something like this: if "%%a"==" xx.xx.xx.x" Goto:good and you should be fine.

Answer 3

To get your public IP without additional parsing do this:

curl "http://api.ipify.org"

EDIT:

This version is more reliable across windows language versions:

for /f "tokens=3 delims== " %%A in ('
nslookup -debug myip.opendns.com. resolver1.opendns.com 2^>NUL^|findstr /C:"internet address"
') do set "ext_ip=%%A"